Details of a Researcher - Banno, Taisuke

Papers - Banno, Taisuke

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Machine learning prediction of self-assembly and analysis of molecular structure dependence on the critical packing parameter

Y Ishiwatari, T Yokoyama, T Kojima, T Banno, N Arai

Molecular Systems Design & Engineering 9 (1), 20-28 (Molecular Systems Design and Engineering) 9 ( 1 ) 20 - 28 2024

Lead author, Last author, Corresponding author, Accepted, ISSN 2058-9689

Amphiphilic molecules spontaneously form self-assembly structures depending on physical conditions such as the molecular structure, concentration, and temperature. These structures exhibit various functionalities according to their morphology. The critical packing parameter (CPP) is used to correlate self-organized structures with the chemical composition. However, accurately calculating it requires information about both the molecular shape and molecular aggregates, making it challenging to apply directly in molecular design. We aimed to predict the self-assembled structure of a molecule directly from its chemical structure and to analyze the factors influencing it using machine learning. Dissipative particle dynamics simulations were used to reproduce many self-assembly structures comprising various chemical structures, and their CPPs were calculated. Machine learning models were built using the chemical structures as input data and the CPPs as output data. As a result, both random forest and the gated recurrent unit showed high prediction accuracy. Feature importance analysis and sample size dependence revealed that the amphiphilic nature of molecules significantly influences the self-assembly structures. Additionally, selecting an appropriate molecular structure representation for each algorithm is crucial. The study results should contribute to product development in the fields of materials science, materials chemistry, and medical materials.

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Bifurcation and Transposition of the Wicking Front of Binary Solutions Infiltrating into Chromatography Paper Associated with Their Evaporation

Amiko Aizawa, Taisuke Banno, Kouichi Asakura

Langmuir (American Chemical Society (ACS)) 39 ( 47 ) 16731 - 16739 2023.11

Lead author, Last author, Corresponding author, Accepted, ISSN 0743-7463

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Photoinduced phase transition between vesicles and coacervates using low-molecular-weight catanionic amphiphiles

Tomoya Kojima, Koichi Terasaka, Kouichi Asakura, Taisuke Banno

Colloids and Surfaces A: Physicochemical and Engineering Aspects (Colloids and Surfaces A: Physicochemical and Engineering Aspects) 669 2023.07

Lead author, Last author, Corresponding author, Accepted, ISSN 0927-7757

Amphiphiles form various molecular self-assemblies in the aqueous phase, such as vesicles and coacervates, depending on molecular properties. Recently, phase transitions between vesicles and coacervates have drawn much attention because the switching between “closed” and “open” compartments could achieve the controllability of molecular sequestrations. We expect that the photoinduced drastic change in the molecular structure of catanionic amphiphiles comprising azobenzene-containing cationic amphiphiles (Azo) and anionic sodium dodecyl sulfate causes the transition. Self-assemblies prepared by a thin-film hydration method were observed using microscopy under UV and subsequent visible-light illumination. Additionally, investigation of selectivity for molecular sequestration and assay of enzymatic reactions in the self-assemblies were conducted. Photoinduced reversible phase transitions between vesicles and coacervates occurred owing to the photoisomerization of Azo. The formed coacervates had selectivity for molecular sequestration. Additionally, the transition achieved fusion of different vesicles via coacervates. Although coacervates are generally known to facilitate enzymatic reactions, the reactions were inhibited in the presence of the formed self-assemblies due to the deactivation of enzymes. Our results represent rapid and non-invasive systems of reversible vesicle–coacervate transitions. Furthermore, the findings provide a new aspect of coacervates in which catanionic low-molecular-weight amphiphiles could act as suppressors of chemical reactions.

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Factors to control the alignment of surface-treated titanium dioxide powders to maximize performance of sunscreens.

Shoji Takekawa, Miwa Ohara, Taisuke Banno, Kouichi Asakura

International journal of cosmetic science (International Journal of Cosmetic Science) 45 ( 1 ) 38 - 49 2023.02

Lead author, Last author, Corresponding author, Accepted, ISSN 0142-5463

OBJECTIVE: Titanium dioxide powders are contained in a large class of colour cosmetics and sunscreen formulas. When they are used, the formation of a uniform functional powder layer on the skin is an important factor to show their functionality, such as aesthetic and UV protection. Attempts were made to extract the factors that affect the UV shielding ability of the deposited powder layer. METHODS: Seven kinds of surface treatments were conducted on nano-sized titanium dioxide powder to modify the surface characteristics. Dispersion samples were prepared by mixing these powders with liquids, such as mixed solutions of cyclopentasiloxane, isododecane, coconuts alkane and dimethicone using a disperser and a bead mill. The dispersions were applied using an applicator on cellulose triacetate film, polycarbonate film and polymethyl pentene film. Laser microscope observation and micro-gloss glossmeter analysis were carried out to assess the flatness of the deposited powder layers, and the UV shielding ability was evaluated using SPF analyser. RESULTS: Factors whose influences on the structure and UV shielding ability of the deposited powder layer being analysed were pseudo-HLB of the powders, liquids for preparing the dispersions and material of the substrates. Higher UV shielding ability was attained when powders having pseudo-HLB at around 6 were employed independent from the kinds of liquids and substrates. Flatness of the deposited layer was found to enhance the UV shielding ability of the UV-B region, while that of the UV-A region was scarcely influenced by the flatness. Employing lower surface tension liquids for preparing the dispersions and materials exhibiting lower polar components of surface free energy as substrates tended to enhance the UV shielding ability. CONCLUSION: Surface treatments conducted on the powders in this study were found to change UV shielding ability, especially UV-B shielding ability, and the relation between pseudo-HLB and UV shielding ability was scarcely influenced by the kinds of liquids. Both surface tension of liquids and the polar component of surface free energy of substrates affected the UV shielding ability. It was suggested that pseudo-HLB calculated based on chemical structure becomes useful information to choose optimum surface treatment to make uniform powder alignment independent from the surrounding environment.

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Photoinduced collective motion of oil droplets and concurrent pattern formation in surfactant solution

Tomoya Kojima, Hiroyuki Kitahata, Kouichi Asakura, Taisuke Banno

Cell Reports Physical Science (Elsevier BV) 4 ( 1 ) 101222 - 101222 2023.01

Lead author, Last author, Corresponding author, Accepted, ISSN 2666-3864

Collective motions are the spontaneous emergence of the ordered movement in living systems. Various constructive approaches have been attempted toward understanding the mechanism. However, few studies have been on the motion induced by biomimetic artificial systems based on molecular conversions. In this study, we report an artificial system of oil droplets in surfactant solutions, wherein collective motion and pattern formation occur concurrently, using the conversion of photoresponsive surfactants. Assembly/dispersion of multiple oil droplets and appearance/disappearance of circular patterns around them occur under UV/visible light illumination, respectively. Moreover, whether the assembled droplets move laterally or not depends on the number of droplets, which is considered analogous to biological organisms in response to population density. These phenomena occur because the photoisomerization of surfactants induces the gradient of interfacial tension, generating specific flow fields around droplets. Our results could be useful for understanding the mechanism of life motion in terms of physicochemical aspects.

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Factors to control the alignment of surface‐treated titanium dioxide powders to maximize performance of sunscreens

S Takekawa, M Ohara, T Banno, K Asakura

International Journal of Cosmetic Science 45 (1), 38-49 2023

Lead author, Last author, Corresponding author, Accepted

Synthesis of Mannosylerythritol Lipid Analogues and their Self-Assembling Properties, Recovery Effects on Damaged Skin Cells, and Antibacterial Activity.

Takanori Kondo, Chihiro Yasui, Ikkei Miyajima, Taisuke Banno, Kouichi Asakura, Tokuma Fukuoka, Kazunori Ushimaru, Maito Koga, Azusa Saika, Tomotake Morita, Yoshiaki Takahashi, Chigusa Hayashi, Masayuki Igarashi, Daisuke Takahashi, Kazunobu Toshima

Chemistry (Weinheim an der Bergstrasse, Germany) (Chemistry - A European Journal) 28 ( 55 ) 2022.06

Lead author, Last author, Corresponding author, Accepted, ISSN 0947-6539

Synthesis of three types of purpose-designed mannosylerythritol lipid (MEL)-D analogues with decanoyl groups (C10), β-GlcEL-D, α-GlcEL-D, and α-MEL-D, was accomplished utilizing our boron-mediated aglycon delivery (BMAD) methods. Their self-assembling properties, recovery effects on damaged skin cells, and antibacterial activity were evaluated. It was revealed, for the first time, that α-GlcEL-D and α-MEL-D only generated giant vesicles, indicating that slight differences in the steric configuration of an erythritol moiety and fatty acyl chains affect the ability to form vesicles. Analogue α-MEL-D exhibited significant recovery effects on damaged skin cells. Furthermore, α-MEL-D exhibited antibacterial activity as high as that for MEL-D, indicating that α-MEL-D is a promising artificial sugar-based material candidate for enhancing the barrier function of the stratum corneum, superior to a known cosmetic ingredient, and possesses antibacterial activity.

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Construction of Supramolecular Systems That Achieve Lifelike Functions

Taisuke Banno, Daichi Sawada, Taro Toyota

MATERIALS (MDPI) 15 ( 7 ) 2391 2022.04

Accepted, ISSN 1996-1944

The Nobel Prize in Chemistry was awarded in 1987 and 2016 for research in supramolecular chemistry on the "development and use of molecules with structure-specific interactions of high selectivity" and the "design and production of molecular machines", respectively. This confirmed the explosive development of supramolecular chemistry. In addition, attempts have been made in systems chemistry to embody the complex functions of living organisms as artificial non-equilibrium chemical systems, which have not received much attention in supramolecular chemistry. In this review, we explain recent developments in supramolecular chemistry through four categories: stimuli-responsiveness, time evolution, dissipative self-assembly, and hierarchical expression of functions. We discuss the development of non-equilibrium supramolecular systems, including the use of molecules with precisely designed properties, to achieve functions found in life as a hierarchical chemical system.

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Chemotaxis of Oil Droplets and Their Phase Transition to Aggregates with Membrane Structures in Surfactant Solution Containing Metal Salts

Sepia Nakayama, Tomoya Kojima, Mari Kaburagi, Takanori Kikuchi, Kouichi Asakura, Taisuke Banno

CHEMSYSTEMSCHEM (WILEY) 4 ( 2 ) 2022.03

Lead author, Last author, Corresponding author, Accepted, ISSN 2570-4206

The movement of supramolecular self-assemblies has been induced by the application of external stimuli that cause a shift to non-equilibrium conditions. However, few supramolecular chemical systems exist in which multiple different functions are associated with movement. Herein, we observed multiple phase transition of micrometer-sized lauronitrile oil droplets in a solution of cationic surfactants with aniline skeletons in the presence of metal ions. These dynamics include tactic motion and subsequent formation of aggregates with membrane structures, in a linear-type channel. These dynamic behaviors result from variations in the interfacial tension at the droplet surface and the chemical compositions owing to the interactions between system components. The current findings may provide a methodology for designing molecular systems in which multi-step phase transitions of supramolecular self-assemblies are coupled to movement in non-equilibrium conditions.

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Self-Assembling Properties and Recovery Effects on Damaged Skin Cells of Chemically Synthesized Mannosylerythritol Lipids.

Takanori Kondo, Chihiro Yasui, Taisuke Banno, Kouichi Asakura, Tokuma Fukuoka, Kazunori Ushimaru, Maito Koga, Hiroyuki Minamikawa, Azusa Saika, Tomotake Morita, Daisuke Takahashi, Kazunobu Toshima

Chembiochem : a European journal of chemical biology (ChemBioChem) 23 ( 2 ) e202100631 2022.01

Accepted, ISSN 14394227

Mannosylerythritol lipids (MELs), which are one of the representative sugar-based biosurfactants (BSs) produced by microorganisms, have attracted much attention in various fields in the sustainable development goals (SDGs) era. However, they are inseparable mixtures with respect to the chain length of the fatty acids. In this study, self-assembling properties and structure-activity relationship (SAR) studies of recovery effects on damaged skin cells using chemically synthesized MELs were investigated. It was revealed, for the first time, that synthetic and homogeneous MELs exhibited significant self-assembling properties to form droplets or giant vesicles. In addition, a small difference in the length of the fatty acid chains of the MELs significantly affected their recovery effects on the damaged skin cells. MELs with medium or longer length alkyl chains exhibited much higher recovery effects than that of C18-ceramide NP.

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New in vitro SPF Evaluation Method for Hydrophilic Sunscreen Samples

Kurumi Ikawa, Amiko Aizawa, Taisuke Banno, Miyuki Fujishiro, Shoichi Yahagi, Akihiro Kuroda, Kouichi Asakura

JOURNAL OF OLEO SCIENCE (JAPAN OIL CHEMISTS SOC) 71 ( 2 ) 321 - 331 2022

Accepted, ISSN 13458957

A new method was developed for the in vitro sun protection factor (SPF) evaluation of sunscreen samples. A new type of substrate, a hydroxyalkyl cellulose-coated plate, was also prepared specifically for hydrophilic samples. This new substrate was required because hydrophilic samples would be unlikely to wet the surface of the standard cosmetic PMMA UV evaluation plate. A super-hydrophilic quartz plate was prepared by corona-discharge treatment before an aqueous solution of hydroxyalkyl cellulose was spread on it. A flat and uniform hydroxyalkyl cellulose film was subsequently formed through the evaporation of water. Special care was taken to inhibit the generation of spatial non-uniformity. Six hydrophilic sunscreen samples with in vivo SPF values of 56, 55, 52, 25, 15, and 4, were then applied to the prepared hydroxyalkyl cellulose-coated plate, as well as a super-hydrophilic quartz plate and a flat hydrophobic PMMA plate. The thicknesses of the applied layers were determined using a wheel-shaped wet film thickness gauge immediately after the application, and UV transmission was measured using an SPF analyzer. The value of in vitro SPF was calculated from the UV absorbance and the thickness of the layer. For two out of the six samples, PMMA plate could not be available, as the samples were unable to wet the PMMA surface. Relatively small differences were observed between the in vitro SPF values when the super-hydrophilic and hydroxyalkyl cellulose-coated plates were used. Samples exhibiting higher in vivo SPF were also associated with higher in vitro SPF values, although a linear relationship was not observed. In contrast to the super hydrophilic plate whose half-life of the super-hydrophilicity is only approximately five days, the hydrophilicity of the hydroxyalkyl cellulose-coated plate scarcely varied during six months of storage. Finally, a simplified evaluation method was also proposed. The validity of the method was verified through a ring test where three researchers employed this method in different laboratories at three independent organizations.

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Synthesis of Mannosylerythritol Lipid Analogues and their Self‐Assembling Properties, Recovery Effects on Damaged Skin Cells, and Antibacterial Activity

T Kondo, C Yasui, I Miyajima, T Banno, K Asakura, T Fukuoka, ...

Chemistry–A European Journal 28 (55), e202201733 2022

Lead author, Last author, Corresponding author, Accepted

pH-Sensitive Controlled Motion of Micrometer-sized Oil Droplets in a Solution of Surfactants Containing Fumaric Acid Derivatives

Mari Kaburagi, Tomoya Kojima, Kouichi Asakura, Taisuke Banno

JOURNAL OF OLEO SCIENCE (JAPAN OIL CHEMISTS SOC) 71 ( 9 ) 1319 - 1326 2022

Lead author, Last author, Corresponding author, Accepted, ISSN 1345-8957

Self-propelled droplets are of considerable interest as an appropriate model for understanding the self-propulsion of objects in the fields of nonequilibrium physics and nonlinear science. Several research groups have reported the monodirectional motion of droplets, that is, chemotaxis, using stimuli-responsive materials. However, the precise control of chemotaxis remains challenging from the perspective of synthetic chemistry because chemotactic motion is primarily induced by the consumption of reactive oil or surfactants. Herein, we report a chemical system containing pH-responsive fumaric acid derivatives, in which the oil droplet exhibited positive chemotaxis over a wide pH range-from basic to acidic conditions. From the measurements of the interfacial tension between the oil and aqueous phases, it was deduced that the positive chemotaxis was due to heterogeneity in the interfacial tension of the droplet surface, which was accompanied by the production of surface-active compounds in the pH gradient in a linear-type channel.

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Pathway-Dependent Phase Transitions of Supramolecular Self-assemblies Containing Cationic Amphiphiles with Azobenzene and Disulfide Groups

Daichi Sawada, Kouichi Asakura, Taisuke Banno

CHEMISTRY-A EUROPEAN JOURNAL (WILEY-V C H VERLAG GMBH) 27 ( 55 ) 13840 - 13845 2021.10

Accepted, ISSN 09476539

There have been several attempts to construct supramolecular chemical systems that mimic the phase transitions in living systems. However, most of these phase transitions are one-to-one and induced by one stimulus or chemical; there have been few reports on the pathway-dependent phase transition of supramolecular self-assemblies in multi-step. To induce multistep phase transitions, molecular crystals were prepared that contained a cationic amphiphile bearing azobenzene and disulfide groups. A reducing agent caused the crystals to become vesicles, and adjacent, non-touching vesicles fused under UV and subsequent visible light. Adding a reducing agent to the worm-like aggregates that were generated after UV irradiation of the original crystals resulted in the growth of sheet-like aggregates. H-1 NMR and fluorescence anisotropy measurements showed that a series of phase transitions was induced by changes in the phase structures from molecular conversions of the reactive amphiphiles. The multiple pathway-dependent phase transitions of supramolecular self-assemblies can provide a methodology for developing new stimuli-responsive materials that exhibit the desirable properties under specific circumstances from a systems chemistry viewpoint.

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How to Control Powder Alignment to Maximize Functionality and Performance of Color Cosmetics and Sunscreen

Shoji Takekawa, Miwa Ohara, Taisuke Banno, Kouichi Asakura

JOURNAL OF OLEO SCIENCE (JAPAN OIL CHEMISTS SOC) 70 ( 8 ) 1081 - 1091 2021

Accepted, ISSN 13458957

Control of powder alignment is essential for maximizing the functionality of color cosmetics and sunscreens. Various surface treatments were applied to nanosized titanium dioxide to modify their surface characteristics. Such modifications can be used to control the behavior of dispersions in cosmetics, enabling them to align uniformly. The powders were mixed with solvents and applied to a cellulose triacetate film. The features of powder alignment on the film were evaluated using several approaches. When the type of surface treatment changed by varying the weight ratio, there was no significant correlation between its alignment and treatment. However, when we focused on the pseudo-HLB each treated pigment, their alignments were correlated. It was confirmed that the powders subjected to the appropriate surface treatment combinations from the pseudo-HLB standpoint made it possible to align uniformly and create a smooth coating film. As a result, it has a high UV-shielding ability. The surface-treated powders in this study were found to change the UV shielding ability and surface roughness of the layer formed when they were formed by spreading the sample powder dispersion and drying of the film. It was suggested that the pseudoHLB, which is calculated based on the chemical structure after the surface treatment process, is useful for choosing the optimum surface treatment to create a uniformly aligned pigment layer.

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pH-Tolerant giant vesicles composed of cationic lipids with imine linkages and oleic acids

Daichi Sawada, Ayana Hirono, Kouichi Asakura, Taisuke Banno

RSC ADVANCES (ROYAL SOC CHEMISTRY) 10 ( 56 ) 34247 - 34253 2020.09

Accepted

Giant vesicles (GVs) have attracted attention as functional materials because they can encapsulate both hydrophilic and hydrophobic compounds. For next generation functional GVs, both tolerance and stimuli-sensitivity are needed. So far, vesicles tolerant to acidic or basic conditions were generated using a mixture of cationic lipids and fatty acids. Here, to create functional GVs that are tolerant to a wide pH range but sensitively respond at below a specific pH, the behaviour of GVs composed of a cationic lipid with an imine bond and oleic acid was investigated. Even though the GVs prepared by the film swelling method were tolerant to strongly acidic conditions, GVs without oleic acid gradually shrank, accompanied by the generation of oil droplets at the same pH.H-1 NMR analysis revealed that during hydration of the film, the imine bond hydrolysed to provide a cationic surfactant and an oil component in the presence of oleic acid due to its own Lewis basicity, suggesting the dissociation of oleic acid. The results of fluorescence spectroscopy using an environment-responsive probe and IR spectroscopy indicated that the GV tolerance originated from the intermolecular interactions of cationic lipids and anionic oleate.

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Cell-Mimicry Behaviors of Micrometer-Sized Oil Droplets in Aqueous Solution

Taisuke Banno, Taro Toyota, Kouichi Asakura

ALIFE 2018: The 2018 Conference on Artificial Life (ALIFE 2018 - 2018 Conference on Artificial Life: Beyond AI) 30 13 - 14 2020

Accepted

In cell system, dynamic behaviors of nanometer- and micrometer-sized living tissues are induced through various chemical reaction networks accompanied with molecular conversions of key molecules. However, such hierarchy between macroscopic dynamics of cells and molecular conversions is very complicated. Here, as a tool for understanding the essence of the dynamic behavior found in cell system, two chemical systems for droplets exhibiting cell-mimicry behaviors have been described: transformation of molecular aggregates and locomotion mode of oil droplets.

Temperature-Dependent Dynamics of Giant Vesicles Composed of Hydrolysable Lipids Having an Amide Linkage

M. Tameyuki, H. Hiranaka, T. Toyota, K. Asakura, T. Banno*

Langmuir (Langmuir) 35 ( 52 ) 17075 - 17081 2019.12

Accepted, ISSN 07437463

Various amphiphiles including surfactants and lipids have been designed and synthesized to improve and create new functionalities. In particular, the emergence of cell-like behaviors of giant vesicles (GVs) composed of synthetic lipids has drawn much attention in the development of chemical models for cells. The aim of this study was to measure temperature-dependent morphological changes of GVs induced by fragmentation and subsequent growth using hydrolysable cationic lipids having an amide linkage. Results from differential scanning calorimetry, fluorescence spectroscopy using an environment-responsive probe, and confocal Raman microscopy showed that the dynamics observed were due to changes in the vesicle membrane, including variation in the lipid composition, induced by thermal stimulation.

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Start of Micrometer-Sized Oil Droplet Motion through Generation of Surfactants

Yui Kasuo, Hiroyuki Kitahata, Yuki Koyano, Masahiro Takinoue, Kouichi Asakura, Taisuke Banno

Langmuir (American Chemical Society ({ACS})) 35 ( 41 ) 13351 - 13355 2019.10

Accepted, ISSN 07437463

Self-propelled motion of micrometer-sized oil droplets in surfactant solution has drawn much attention as an example of nonlinear life-like dynamics under far-from-equilibrium conditions. The driving force of this motion is thought to be induced by Marangoni convection based on heterogeneity in the interfacial tension at the droplet surface. Here, to clarify the required conditions for the self-propelled motion of oil droplets, we have constructed a chemical system, where oil droplet motion is induced by the production of 1,2,3-triazole-containing surfactants through the Cu-catalyzed azide-alkyne cycloaddition reaction. From the results of the visualization and analysis of flow fields around the droplet, the motion of the droplets could be attributed to the formation of flow fields, which achieved sufficient strength caused by the in situ production of surfactants at the droplet surface.

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Disruption of Liquid Marbles Induced by Host-Guest Interaction

Shohei Kozuka, Taisuke Banno, Syuji Fujii, Yoshinobu Nakamura, Shin-ichi Yusa

CHEMISTRY LETTERS (CHEMICAL SOC JAPAN) 48 ( 8 ) 840 - 843 2019

Accepted, ISSN 03667022

The present work describes the preparation of host-guest complex formation-responsive liquid marbles (LMs) composed of a water droplet and hydrophobic adamantane (AD) powder. The importance of hydrophobic and hydrophilic balance to the stability of LM was demonstrated with this system. The hydrophobic AD powder formed an amphiphilic system upon formation of a host-guest complex with methyl-beta-cyclodextrin (CD). Although the LM was stable for more than one hour on the water surface, it collapsed on the surface of a CD aqueous solution within a few minutes due to formation of the AD-CD complex.

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Surface Structures of Cosmetic Standard Poly Methyl Methacrylate UV Evaluation Plates and their Influence on the in vitro Evaluation of UV Protection Abilities of Cosmetic Sunscreens

Akihiro Kuroda, Karin Sakai, Shoichi Yahagi, Tsubasa Mukawa, Nobumasa Sato, Naoki Nakamura, Daisuke Maezawa, Hitoshi Masaki, Taisuke Banno, Kouichi Asakura

JOURNAL OF OLEO SCIENCE (JAPAN OIL CHEMISTS SOC) 68 ( 2 ) 175 - 182 2019

Accepted, ISSN 13458957

Cosmetic standard poly methyl methacrylate (PMMA) UV evaluation plates, i.e., roughened PMMA plates, are used in the EU and the US for the in vitro evaluation of UV protection abilities of sunscreen, such as in vitro UVA-PF and critical wavelength for the Broad-spectrum approval. In our previous studies, inhomogeneity in the thickness of a pseudo-sunscreen layer applied on a flat quartz plate was observed to alter UV transmission. Thus, the surface roughness of the standard plates should have a significant influence on the in vitro evaluation. In the present study, we have analyzed the surface structures of three cosmetic standard PMMA UV evaluation plates: Helioplates HD6 (Sa = 6 mu m) and ISO plates (Ra = 2 and 5 mu m). A decamethylcyclopentasiloxane and 2-propanol-mixed solvent solution of acrylsilicone resin was prepared, and the solution was added dropwise onto the plates. After the evaporation of the solvents, the plates were cut and the cross section was analyzed using SEM-EDS. The distribution of silicon atoms at the cross-section suggested that the maximum depth of penetrating of acrylsilicone resin was larger than Ra for all the standard plates, and the surface structure was significantly different for each standard plate. In addition, cracks into which the acrylsilicone resin deeply penetrated were observed on the surface of some plates. Clear-solution-type pseudo-sunscreen samples in which UV absorbers and acrylsilicone resin were dissolved were deposited on the standard roughened PMMA plates. It was observed that the addition of acrylsilicone resin drastically changed the net UV transmission. The degree to which the hollows of the roughened surface were filled with the pseudo-sunscreen samples determined the variation of UV transmittance.

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Irreversible aggregation of alternating tetrablock- like amphiphile in water

Shota Konno, Taisuke Banno, Hideaki Takagi, Satoshi Honda, Taro Toyota

PLOS ONE (PLoS ONE) 13 ( 8 ) e0202816 2018.08

Accepted

As a frontier topic of soft condensed matter physics, irreversible aggregation has drawn attention for a better understanding of the complex behavior of biomaterials. In this study, we have described the synthesis of an artificial amphiphilic molecule, an alternating tetra-block-like amphiphile, which was able to diversify its aggregate structure in water. The aggregated state of its aqueous dispersion was obtained by slow evaporation of the organic solvent at room temperature, and it collapsed irreversibly at ~ 50C. By using a cryo-trans-mission electron microscope and a differential scanning calorimeter, it was revealed that two types of molecular nanostructures were formed and developed into submicro- and micrometer-sized fibrils in the aggregated material.

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Locomotion Mode of Micrometer-Sized Oil Droplets in Solutions of Cationic Surfactants Having Ester or Ether Linkages

Ayana Hirono, Taro Toyota, Kouichi Asakura, Taisuke Banno

Langmuir (Langmuir) 34 ( 26 ) 7821 - 7826 2018.07

Accepted, ISSN 07437463

Micrometer-sized self-propelled oil droplets under a far-from-equilibrium condition have drawn much attention because of their potential as a dynamic model for the chemical machinery in living organisms. To clarify the effect of interactions between the system components (surfactant, oil, and water) on the locomotion mode of droplets, we investigated the behaviors of oil droplets composed of n-heptyloxybenzaldehyde (HBA) in solutions of cationic surfactants having or not having an ester or an ether linkage. It was observed that in solutions of cationic surfactants having an ester or an ether linkage, spherical HBA droplets self-propelled by changing their direction frequently. On the other hand, when this functional group is absent, a slow self-propelled motion of the oil droplets concurrent with the evolution of aggregates on their surface was observed. From the results of measurement of interfacial tension and assessment of self-emulsification, we determined that the attractive interactions of cationic surfactants without an ester or an ether linkage with HBA are stronger than those having the linkage. The difference in the locomotion mode of oil droplets is probably explained from the viewpoint of the interactions among the system components.

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Droplets As Liquid Robots

J. Čejková, T. Banno, M. M. Hanczyc, F. Štěpánek

Artificial Life 23 528 - 549 2017.12

Lead author, Last author, Corresponding author, Accepted

Locomotion and Transformation of Underwater Micrometer-Sized Molecular Aggregates under Chemical Stimuli

Toyota, Taro, Banno, Taisuke, Castro, Juan M., Imai, Masayuki

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN (PHYSICAL SOC JAPAN) 86 ( 10 ) 528 - 549 2017.10

Research paper (scientific journal), Accepted, ISSN 0031-9015

In this review paper, we introduce the mobility and transformation of micrometer-sized molecular aggregates (i.e., oil droplets, liquid crystalline droplets and tubes, and giant vesicles) in water under chemical stimuli. These molecular aggregates comprising lipophilic and/or amphiphilic molecules have drawn much attention as plausible prebiotic cellular structures and dynamic microreactors related to the origins of life. Here, we highlight recent advances and issues concerning the construction of such systems and discuss the implications of these findings to our understanding of protocellular systems.

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Sequential dynamic structuralisation by in situ production of supramolecular building blocks

Yuasa, Hirohiko, Asakura, Kouichi, Banno, Taisuke

CHEMICAL COMMUNICATIONS (ROYAL SOC CHEMISTRY) 53 ( 61 ) 8553 - 8556 2017.08

Research paper (scientific journal), Accepted, ISSN 1359-7345

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Self-Propelled Motion of Monodisperse Underwater Oil Droplets Formed by a Microfluidic Device

Ueno, Naoko, Banno, Taisuke, Asami, Arisa, Kazayama, Yuki, Morimoto, Yuya, Osaki, Toshihisa, Takeuchi, Shoji, Kitahata, Hiroyuki, Toyota, Taro

LANGMUIR 33 ( 22 ) 5393 - 5397 2017.06

Research paper (scientific journal), Accepted, ISSN 0743-7463

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Phototactic behavior of self-propelled micrometer-sized oil droplets in a surfactant solution

Sho Kaneko, Kouichi Asakura, Taisuke Banno

CHEMICAL COMMUNICATIONS (ROYAL SOC CHEMISTRY) 53 ( 14 ) 2237 - 2240 2017.02

Lead author, Last author, Corresponding author, Accepted, ISSN 1359-7345

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Self-Propelled Oil Droplets and Their Morphological Change to Giant Vesicles Induced by a Surfactant Solution at Low pH

Taisuke Banno, Yuki Tanaka, Kouichi Asakura, Taro Toyota

LANGMUIR (AMER CHEMICAL SOC) 32 ( 37 ) 9591 - 9597 2016.09

Lead author, Last author, Corresponding author, Accepted, ISSN 0743-7463

Unique dynamics using inanimate molecular assemblies based on soft matter have drawn much attention for demonstrating far-from-equilibrium chemical systems. However, there are no soft matter systems that exhibit a possible pathway linking the self-propelled oil droplets to formation of giant vesicles stimulated by low pH. In this study, we conceived an experimental oil-in-water emulsion system in which flocculated particles composed of a imine-containing oil transformed to spherical oil droplets that self-propelled and, after coming to rest, formed membranovs figures. Finally, these figures became giant vesicles. From NMR, pH curves, and surface tension measurements, we determined that this far-from-equilibrium phenomenon was due to the acidic hydrolysis of the oil, which, produced a benzaldehyde derivative as an component and a primary amine as a surfactant precursor, and, the dynamic behavior of the hydrolytic products in the emulsion system. These findings afforded us a potential linkage between mobile droplet-based protocells and vesicle-based protocells stimulated by low pH.

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Deformable Self-Propelled Micro-Object Comprising Underwater Oil Droplets

Taisuke Banno, Arisa Asami, Naoko Ueno, Hiroyuki Kitahata, Yuki Koyano, Kouichi Asakura, Taro Toyota

SCIENTIFIC REPORTS (NATURE PUBLISHING GROUP) 6 31292 2016.08

Lead author, Last author, Corresponding author, Accepted, ISSN 2045-2322

The self-propelled motion with deformation of micrometer-sized soft matter in water has potential application not only for underwater carriers or probes in very narrow spaces but also for understanding cell locomotion in terms of non-equilibrium physics. As far as we know, there have been no reports about micrometer-sized self-propelled soft matter mimicking amoeboid motion underwater. Here, we report an artificial molecular system of underwater oil droplets exhibiting self-propelled motion with deformation as an initial experimental model. We describe the heterogeneity in a deformable self-propelled oil droplet system in aqueous and oil phases and at their interface based on the behavior and interaction of surfactant and oil molecules. The current results have great importance for scientific frontiers such as developing deformable micro-swimmers and exploring the emergence of self-locomotion of oil droplet-type protocells.

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Controlled polymerization of acrylonitrile proceeded along with the Belousov-Zhabotinsky oscillator by changing its stirring conditions

Yuuka Furue, Kunihiko Okano, Taisuke Banno, Kouichi Asakura

CHEMICAL PHYSICS LETTERS (ELSEVIER SCIENCE BV) 645 210 - 214 2016.02

Lead author, Last author, Corresponding author, Accepted, ISSN 0009-2614

Chemical oscillations of the manganese-ion catalyzed Belousov-Zhabotinsky (BZ) reaction system were found to be controlled by changing its stirring conditions. The oscillation stopped at a high stirring rate, while it reappeared immediately by reducing the stirring rate. It is known in the BZ reaction system, that the radical polymerization takes place along with the oscillation when acrylic monomers are added. By the addition of acrylonitrile to the system stirred at a high stirring rate, the oscillation as well as the polymerization of acrylonitrile stopped. The radical polymerization of acrylonitrile by the BZ oscillator is thus found to be made controllable by changing the mixing conditions. (C) 2015 Elsevier B.V. All rights reserved.

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Design of Reactive Surfactants that Control the Locomotion Mode of Cell-Sized Oil Droplets

Banno Taisuke

Current Physical Chemistry 5 ( 1 ) 37 - 51 2015.10

Lead author, Last author, Corresponding author, Accepted

Molecular System for the Division of Self-Propelled Oil Droplets by Component Feeding

Taisuke Banno, Taro Toyota

LANGMUIR (AMER CHEMICAL SOC) 31 ( 25 ) 6943 - 6947 2015.06

Lead author, Last author, Corresponding author, Accepted, ISSN 0743-7463

Unique dynamics using inanimate molecular assemblies have drawn a great amount of attention for demonstrating prebiomimetic molecular systems. For the construction of an organized logic combining two fundamental dynamics of life, we demonstrate here a molecular system that exhibits both division and self-propelled motion using oil droplets. The key molecule of this molecular system is a novel cationic surfactant containing a five-membered acetal moiety, and the molecular system can feed the self-propelled oil droplet composed of a benzaldehyde derivative and an alkanol. The division dynamics of the self-propelled oil droplets were observed through the hydrolysis of the cationic surfactant in bulk solution. The mechanism of the current dynamics is argued to be based on the supply of "fresh" oil components in the moving oil droplets, which is induced by the Marangoni instability. We consider this molecular system to be a prototype of self-reproducing inanimate molecular assembly exhibiting self-propelled motion.

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Micrometer-sized network structure of novel DNA-lipid conjugates induced by heat stimulation

K. Takahashi, M. Matsuo, T. Banno, T. Toyota

SOFT MATTER (ROYAL SOC CHEMISTRY) 11 ( 35 ) 7053 - 7058 2015

Lead author, Last author, Corresponding author, Accepted, ISSN 1744-683X

We have developed a novel lipid-bearing DNA that forms hairpin modules, including a single RNA monomer; this can be used to create micrometer-sized structures from nanometer-sized building blocks during breakage at the RNA site. In the presence of divalent metal ions and heat stimulation, we observed transition of the self-assembly, which results in the formation of a three-dimensional network structure. To our knowledge, this is also the first report of heat-induced micrometer-sized molecular self-assembly of molecules that carry biological information.

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Multiple-division of self-propelled oil droplets through acetal formation

Taisuke Banno, Rie Kuroha, Shingo Miura, Taro Toyota

SOFT MATTER (ROYAL SOC CHEMISTRY) 11 ( 8 ) 1459 - 1463 2015

Lead author, Last author, Corresponding author, Accepted, ISSN 1744-683X

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Giant Vesicle Formation of Novel Polymerizable Amphiphile Associated with Its Polymerization and Hydrolysis in Water

Taisuke Banno, Yuki Kazayama, Taro Toyota

CHEMISTRY LETTERS (CHEMICAL SOC JAPAN) 43 ( 11 ) 1707 - 1709 2014.11

Lead author, Last author, Corresponding author, Accepted, ISSN 0366-7022

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Molecular Building Blocks and Their Architecture in Biologically/Environmentally Compatible Soft Matter Chemical Machinery

Taro Toyotat, Taisuke Banno, Sachiko Nitta, Masahiro Takinoue, Tomonori Nomoto, Yuno Natsume, Shuichi Matsumura, Masanori Fujinami

JOURNAL OF OLEO SCIENCE (JAPAN OIL CHEMISTS SOC) 63 ( 11 ) 1085 - 1098 2014.11

Lead author, Last author, Corresponding author, Accepted, ISSN 1345-8957

This review briefly summarizes recent developments in the construction of biologically/environmentally compatible chemical machinery composed of soft matter. Since environmental and living systems are open systems, chemical machinery must continuously fulfill its functions not only through the influx and generation of molecules but also via the degradation and dissipation of molecules. If the degradation or dissipation of soft matter molecular building blocks and biomaterial molecules/polymers can be achieved, soft matter particles composed of them can be used to realize chemical machinery such as self-propelled droplets, drug delivery carriers, tissue regeneration scaffolds, protocell models, cell-/tissue-markers, and molecular computing systems.

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pH-Induced Motion Control of Self-Propelled Oil Droplets Using a Hydrolyzable Gemini Cationic Surfactant

Shingo Miura, Taisuke Banno, Taishi Tonooka, Toshihisa Osaki, Shoji Takeuchi, Taro Toyota

LANGMUIR (AMER CHEMICAL SOC) 30 ( 27 ) 7977 - 7985 2014.07

Lead author, Last author, Corresponding author, Accepted, ISSN 0743-7463

Self-propelled motion of micrometer-sized substances has drawn much attention as an autonomous transportation system. One candidate vehicle is a chemically driven micrometer-sized oil droplet. However, to the best of our knowledge, there has been no report of a chemical reaction system controlling the three-dimensional motion of oil droplets underwater. In this study, we developed a molecular system that controlled the self-propelled motion of 4-heptyloxybenzaldehyde oil droplets by using novel gemini cationic surfactants containing carbonate linkages (2G12C). We found that, in emulsions containing sodium hydroxide, the motion time of the self-propelled oil droplets was longer in the presence of 2G12C than in the presence of gemini cationic surfactants without carbonate linkages. Moreover, in 2G12C solution, oil droplets at rest underwent unidirectional, self-propelled motion in a gradient field toward higher concentration of sodium hydroxide. Even though they stopped within several seconds, they restarted in the same direction. 2G12C was gradually hydrolyzed under basic conditions to produce a pair of the corresponding monomeric surfactants, which exhibit different interfacial properties from 2G12C. The prolonged and restart motion of the oil droplets were explained by the increase in the heterogeneity of the interfacial tension of the oil droplets.

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Mode Changes Associated with Oil Droplet Movement in Solutions of Gemini Cationic Surfactants

Taisuke Banno, Shingo Miura, Rie Kuroha, Taro Toyota

LANGMUIR (AMER CHEMICAL SOC) 29 ( 25 ) 7689 - 7696 2013.06

Lead author, Last author, Corresponding author, Accepted, ISSN 0743-7463

Micrometer-sized self-propelled oil droplets in nonequilibrium systems have attracted much attention, since they form stable emulsions composed of oil, water, and surfactant which represent a primitive type of inanimate chemical machinery. In this work, we examined means of controlling the movement of oil droplets by studying the dynamics of n-heptyloxybenzaldehyde droplets in phosphate buffers containing alkanediyl-alpha,omega-bis(N-dodecyl-N,N-dimethylammonium bromide) (nG12) with either tetramethylene (4G12), octaethylene (8G12), or dodecamethylene (12G12) chains in the linker moiety. Significant differences in droplet dynamics were observed to be induced by changes in the linker structure of these gemini cationic surfactants. In a phosphate buffer containing 30 mM 4G12, self-propelled motion of droplets concurrent with the formation of molecular aggregates on their surfaces was observed, whereas the fusion of oil droplets was evident in both 8G12 and 12G12 solutions. We also determined that the surface activities and the extent of molecular self-assembly of the surfactants in phosphate buffer were strongly influenced by the alkyl chain length in the linker moiety. We therefore conclude that the surface activities of the gemini cationic surfactant have important effects on the oil water interfacial tension of oil droplets and the formation of molecular aggregates and that both of these factors induce the unique movement of the droplets.

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pH-Sensitive Self-Propelled Motion of Oil Droplets in the Presence of Cationic Surfactants Containing Hydrolyzable Ester Linkages

Taisuke Banno, Rie Kuroha, Taro Toyota

LANGMUIR (AMER CHEMICAL SOC) 28 ( 2 ) 1190 - 1195 2012.01

Lead author, Last author, Corresponding author, Accepted, ISSN 0743-7463

Self-propelled oil droplets in a nonequilibrium system have drawn much attention as both a primitive type of inanimate chemical machinery and a dynamic model of the origin of life. Here, to create the pH-sensitive self-propelled motion of oil droplets, we synthesized cationic surfactants containing hydrolyzable ester linkages. We found that n-heptyloxybenzaldehyde oil droplets were self-propelled in the presence of ester-containing cationic surfactant. In basic solution prepared with sodium hydroxide, oil droplets moved as molecular aggregates formed on their surface. Moreover, the self-propelled motion in the presence of the hydrolyzable cationic surfactant lasted longer than that in the presence of nonhydrolyzable cationic surfactant. This is probably due to the production of a fatty acid by the hydrolysis of the ester-containing cationic surfactant and the subsequent neutralization of the fatty acid with sodium hydroxide,. A complex surfactant was formed in the aqueous solution because of the cation and anion combination. Because such complex formation can induce both a decrease in the interfacial tension of the oil droplet and self-assembly with n-heptyloxybenzaldehyde and lauric acid in the aqueous dispersion, the prolonged movement of the oil droplet may be explained by the increase in heterogeneity of the interfacial tension of the oil droplet triggered by the; hydrolysis of the ester-containing surfactant.

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[解説] 油中水滴エマルションを用いたジャイアントベシクル型人工細胞の器づくり

豊田太郎*, 伴野太祐, 藤浪真紀

オレオサイエンス 12 ( 2 ) 77 - 84 2012

Lead author, Last author, Corresponding author, Accepted, ISSN 2187-3461

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Chemo-enzymatic Synthesis and Properties of Novel Optically Active Cationics Containing Carbonate Linkages

Taisuke Banno, Kazuo Kawada, Shuichi Matsumura

JOURNAL OF OLEO SCIENCE (JAPAN OIL CHEMISTS SOC) 60 ( 4 ) 185 - 195 2011.04

Lead author, Last author, Corresponding author, Accepted, ISSN 1345-8957

Novel optically active carbonate-type cationics were designed and synthesized via a green method. A series of n-alkyl N,N-dimethylaminoalkyl carbonates was prepared via a two-step successive carbonate exchange reaction of diphenyl carbonate with 1-alkanol followed by the reaction of the optically active or racemic amino alcohol in the presence of triethylamine. The quaternarization of the N,N-dimethylamino group was carried out using methyl iodide. Furthermore, optically active cationics were prepared by the lipase-catalyzed enantioselective hydrolysis of the racemic cationics. Carbonate-type cationics having an isopropylene linkage showed high hydrolytic stability. They exhibited surfactant properties similar to those of the corresponding racemic cationics. Although no significant differences in the antimicrobial activities were observed owing to the stereochemistry of the cationics, the biodegradability was strongly influenced by the stereochemistry. Some optically active cationics were rapidly biodegraded by activated sludge.

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Synthesis and Properties of Green Sustainable Carbonate-type Nonionics Containing Polyoxyethylene Chains

Taisuke Banno, Hiroshi Sato, Takayuki Tsuda, Shuichi Matsumura

JOURNAL OF OLEO SCIENCE (JAPAN OIL CHEMISTS SOC) 60 ( 3 ) 117 - 126 2011.03

Lead author, Last author, Corresponding author, Accepted, ISSN 1345-8957

A series of polyoxyethylene surfactants containing carbonate linkages as biodegradable and chemically recyclable segments was designed and synthesized by a green process. A two-step carbonate exchange reaction was used: dimethyl or diphenyl carbonate was reacted with 1-alkanol, and the product was reacted with poly (ethylene) glycol in the presence of a lipase or chemical catalyst. The obtained carbonate-type nonionics exhibited good surface-active properties such as a low critical micelle concentration value and a surface tension lowering action. They were readily biodegraded by activated sludge, furthermore, could be chemical recycled using a lipase.

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Creation of Novel Green and Sustainable Gemini-Type Cationics Containing Carbonate Linkages

Taisuke Banno, Kazuo Kawada, Shuichi Matsumura

JOURNAL OF SURFACTANTS AND DETERGENTS (SPRINGER HEIDELBERG) 13 ( 4 ) 387 - 398 2010.10

Lead author, Last author, Corresponding author, Accepted, ISSN 1097-3958

Novel gemini-type cationics containing carbonate linkages as biodegradable and chemically recyclable segments were designed and synthesized by a green process. The carbonate linkages were introduced into only the hydrophobic moiety or in both the hydrophobic and linker moieties of gemini-type cationics. They showed higher surface activities, such as a low critical micelle concentration value, a surface tension lowering, and a high adsorption efficiency, when compared to the corresponding single-type cationics. Also, the gemini-type cationics containing carbonate linkages in both the hydrophobic and the linker moieties showed stronger antimicrobial activities when compared to those only in the hydrophobic moiety. It was found that some gemini-type cationics containing carbonate linkages showed higher biodegradability compared to the conventional gemini-type cationics. The biodegradability of the gemini-type cationics decreased when a carbonate linkage was introduced into the hydrophobic moiety rather than the linker moiety. However, some gemini-type cationics containing carbonate linkages both in the hydrophobic and linker moieties showed ready biodegradability. The gemini-type cationics containing carbonate linkages in the hydrophobic moiety showed chemical recyclability by a lipase (E.C. 3.1.1.3).

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Synthesis and Properties of Polycarboxylate-type Green Surfactants with S- or N-Linkages

Yuu Okada, Taisuke Banno, Kazunobu Toshima, Shuichi Matsumura

JOURNAL OF OLEO SCIENCE (JAPAN OIL CHEMISTS SOC) 58 ( 10 ) 519 - 528 2009.10

Lead author, Last author, Corresponding author, Accepted, ISSN 1345-8957

Polycarboxylate-type green surfactants with either sulfide- (S-) or imino- (N-) linkages were prepared in high yields by a single addition reaction of fatty mercaptan or fatty amine with unsaturated polycarboxylic acids such as fumaric, maleic, itaconic and aconitic acids. They exhibited surfactant properties and excellent biodegradabilities. Also, green surfactants with S-linkages showed better calcium ion sequestration abilities compared to the corresponding surfactant having an N-linkage. Among these surfactants, aconitic acid-derived polycarboxylate with an S-linkage exhibited calcium ion sequestration capacities similar to that of disodium 3-oxapentanedioate (ODA), a conventional calcium ion sequestrant on a molar basis of the surfactant.

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Synthesis and Properties of Gemini-type Cationic Surfactants Containing Carbonate Linkages in the Linker Moiety Directed Toward Green and Sustainable Chemistry

Taisuke Banno, Kazunobu Toshima, Kazuo Kawada, Shuichi Matsumura

JOURNAL OF SURFACTANTS AND DETERGENTS (SPRINGER HEIDELBERG) 12 ( 3 ) 249 - 259 2009.08

Lead author, Last author, Corresponding author, Accepted, ISSN 1097-3958

Gemini-type cationic surfactants containing carbonate linkages as biodegradable and chemically recyclable segments, consisting of two long-chain alkyl groups, two quaternary ammonium groups and a linker moiety, were designed and synthesized as novel green and sustainable cationics with improved physicochemical and biological activities. The gemini-type cationics containing a carbonate linkage showed lower critical micelle concentration values compared to the corresponding single-type cationics. Also, the gemini-type cationics containing a carbonate linkage in the linker moiety showed strong antimicrobial activities. The biodegradability of the gemini-type cationics was significantly improved when a carbonate linkage was introduced into the linker moiety. The maximum biochemical oxygen demand-biodegradability of the gemini-type cationics containing a carbonate linkage in the linker moiety exceeded 70% after a 28-day incubation. Furthermore, the gemini-type cationics containing both a carbonate linkage and an n-dodecyl group showed a chemical recyclability using a lipase (E.C. 3.1.1.3).

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Synthesis and Properties of Biodegradable and Chemically Recyclable Cationic Surfactants Containing Carbonate Linkages

Banno Taisuke, Toshima Kazunobu, Kawada Kazuo, Matsumura Shuichi

Journal of Oil Chemists' Society, Japan (Japan Oil Chemists' Society) 56 ( 9 ) 493 - 499 2007

Lead author, Last author, Corresponding author, Accepted, ISSN 1345-8957

Novel biodegradable and chemically recyclable carbonate-type cationic surfactants consisting of a long chain alkyl group and a quaternary ammonium propyl group were designed and synthesized as a green surfactant. These carbonate-type cationics showed better surface activities in an aqueous solution when compared to the conventional cationics. Novel cationics containing both the carbonate linkage and <i>n</i>-dodecyl group showed strong antimicrobial properties, enzymatic degradabilities for chemical recycling and rapid biodegradabilities by activated sludge.<br>

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