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Thermo-responsive liquid marbles can be prepared using poly(N-isopropylacrylamide) powder and Na2SO4 aqueous solution, which were transferred to the surface of bulk water containing Na2SO4 aqueous solution. They remained stable at room temperature. When the bulk aqueous solution was cooled, the liquid marbles disintegrated because powder wettability increased. Thus, the remote triggering of chemical reactions using liquid marbles can be achieved by cooling.
Dynamic birefringence and viscoelasticity for cellulose acetate butyrate, CAB, were measured simultaneously at various temperatures covering a wide frequency region from the rubbery plateau to the glassy zone in order to discuss the viscoelastic segment size of cellulose. The segment sizes for cellulose derivatives are larger than vinyl polymers, reflecting the stiff chain structure of β-linked D-glucose units (about 10 glucose units per segment).
Mean-square radii of gyration <S2> for two polystyrene samples in toluene and 2-butanone and a cyclic amylose tris(phenylcarbamate) (cATPC) sample in tetrahydrofuran were determined by SAXS between −77 and 70 °C. Whereas <S2> of cATPC does not depend on temperature over the range investigated, those for polystyrene depend to a significant degree. The characteristic ratio for polystyrene in toluene monotonically decreases with increasing temperature. However, that in 2-butanone has a minimum ∼10 °C, suggesting that the RIS energy parameters are affected by the intermolecular interactions between the polymer and solvent.
Nanocomposites based on ethylene-acrylic acid copolymer (EAA) and polyhedral oligomeric silsesquioxanes (POSS) molecules were prepared by melt mixing: partial cage POSS with different pendent organic groups were used to investigate the interaction between the –OH POSS’s groups and the acrylic functionalities of the matrix. All measured properties of EAA/POSS nanocomposites are the result of two contrasting phenomena, particularly, the plasticizer and reinforcement effect. Moreover, the properties of up generation nanocomposites depend significantly on the presence of some functionalities in the components and on possible interaction between them.
One step method for the fabrication of electospun nanofibrous membranes (ENMs) with hydrophilic surfaces and improved flux via in situ polymerization technique is described. The developed membranes also possess enhanced antifouling properties when compared with the virgin PVDF polymer.
The synthesis of amphiphilic poly(dimethylsiloxane) derivatives with quaternized imidazolium salts having alkyne group was achieved. The introduction of the alkyne group enabled coupling with azide-functionalized fluorescent dyes and green fluorescent protein by the click reaction using a copper catalyst. Fluorescence-labeled o/w emulsions were successfully formed using the labeled polymers. Therefore, these polymers would be useful for drug delivery by conjugating cell-specific targeting molecules by the click reaction.
We report the preparation of novel functional microparticles by self-assembly of amphiphilic copolymer composed of poly(γ-glutamic acid) (γ-PGA) as a hydrophilic backbone and dodecylamine (DOA) as a hydrophobic side chain (γ-PGA-DOA). γ-PGA-DOA with a grafting degree of 55% self-assembled by hydrophobic interaction, and formed microparticles (diameter 13±3 μm) in aqueous solution. These microparticles possess functional carboxylic groups, and could be further modified with active compounds such as drugs, proteins and peptides, and thus have great potential as vaccine carriers.
Two polystyrene-based amphiphilic diblock copolymers, PS(x)-PV(y) and PS(x)-PA(y) (where PS(x)-PV(y) and PS(x)-PA(y) possess poly[(ar-vinylbenzyl)trimethylammonium chloride] and poly(2-acrylamido-2-methylpropanesulfonic acid) blocks, respectively, and x and y are the degrees of polymerization), were prepared by reversible addition-fragmentation chain transfer radical polymerization to investigate their formation of reverse micelles in less polar organic media. Theoretical analysis using light scattering data indicated that PS(x)-PV(y) formed star-like micelles at x/y>6 and brush-like micelle micelles at x/y<6 in DCE.
We prepared imidazolium-containing silica hybrid films by sol–gel reactions of 1-(trimethoxysilylpropyl)-3-methylimidazolium chloride under microwave irradiation. Furthermore, we incorporated hydrophobic dyes such as pyrene and 1-pyrenecarboxaldehyde into the silica hybrids, and we investigated dispersion behaviors of these dyes in the matrices. It was suggested that the local heating of the imidazolium groups caused under microwave irradiation contributed to the enhancement to reaction rates in the sol–gel process. Finally, we established to incorporate higher concentration of the dyes into the silica hybrids as compared with the conventional heating.
