We investigated the two-step chemical transformation of a series of symmetric poly(styrene-b-solketal acrylate) (PS-b-PSA) copolymers with varying molecular weights from 1900 to 27?300 g/mol (13 ? N ? 194) synthesized by sequential atom transfer radical polymerization. Through acid-catalyzed hydrolysis, the PSA block is converted into poly(glycerol acrylate) (PGA), which subsequently…
sergio.rodrigues@xenocs.com27 January 2020
The effect of solvent selectivity on the fragmentation kinetics of spherical micelles formed by a 1,2-polybutadiene-block-poly(ethylene oxide) BO copolymer in five 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide-based ionic liquids (ILs), (, where n = methyl, ethyl, butyl, hexyl, and octyl) was investigated by temperature-jump dynamic light scattering (T-jump DLS),
sergio.rodrigues@xenocs.com27 January 2020
Isoporous membranes prepared from the combination of self-assembly and non-solvent induced phase inversion (SNIPS) were known for their asymmetric structures that were characterized with an isoporous top layer and porous/interconnected sublayer. This unique feature provides an opportunity to tailor the structure on toplayer and sublayer separately or synchronously by adjusting…
sergio.rodrigues@xenocs.com27 January 2020
A series of polyethylene-like ionomers with periodic sulfonate groups were synthesized by polyesterification of octatetracontane-1,48-diol and tetrabutylammonium dimethyl sulfosuccinate. Optional cation exchange in aqueous dispersions replaced the NBu4+ counterions for Na+ or Cs+. The defined periodic microstructure of the polymers leads to the formation of layered structures in bulk and…
sergio.rodrigues@xenocs.com27 January 2020
Enantiodifferentiation is crucial in organic chemistry, pharmacochemistry, material chemistry, and life science. However, it remains tremendously challenging to achieve a broad enantioselectivity to different types of chiral substrates via a single-material design. Here, we report a coassembled organogel strategy with chirality transfer to make an enantioselective generality possible. This
sergio.rodrigues@xenocs.com27 January 2020
One of the greatest challenges of robust self-healing materials is the confliction between high chain mobility for self-healing and a stable structure for mechanical strength. Herein, dangling 2-ureido-4-pyrimidione (UPy)-functionalized side groups were introduced into the hard segments of thermoplastic polyurethane (TPU) elastomers, where embedded the dynamic disulfide bonds in the…
sergio.rodrigues@xenocs.com27 January 2020
Self-healing polyurethane with disulfide bonds was synthesized using polycarbonate diol as a soft segment, and methylene diphenyl diisocyanate and 2-hydroxyethyl disulfide as a hard segment. Well-developed phase separation as the hard segments increased was confirmed by Fourier transform infrared spectra. The X-ray diffraction data showed that the crystallinity of the…
sergio.rodrigues@xenocs.com27 January 2020
The Moebius topology (twisted, single-sided strip) is intriguing because of its structural elegance and distinct properties. Here we report the generation of block copolymer Moebius strips via a fast self-assembly of chiral block copolymer polystyrene-block-poly(D-lactide acid) (PS-b-PDLA) in tetrahydrofuran/water mixed solvents. The Moebius strip is formed by morphological evolution from…
sergio.rodrigues@xenocs.com27 January 2020
A new transition between alternating gyroid (GA) structure and cylindrical morphology was observed in thin films for a poly(isoprene-block-styrene-block-(2-vinylpyridine)) (ISP) triblock terpolymer (I/S/P volume fraction = 0.20:0.66:0.14) exhibiting in bulk a Q214 (space group I4132) morphology. Thin films were organized using solvent vapor annealing (SVA) and characterized by atomic force
sergio.rodrigues@xenocs.com27 January 2020
Due to their distinctive molecular architecture, ABA triblock copolymers will undergo specific self-assembly processes into various nanostructures upon introduction into a B-block selective solvent. Although much of the focus in ABA triblock copolymer self-assembly has been on equilibrium nanostructures, little attention has been paid to the guiding principles of nanostructure…
sergio.rodrigues@xenocs.com27 January 2020