Rod-Like Amphiphile of Diblock Polyisocyanate Leading to Cylindrical Micelle and Spherical Vesicle in Water

Synthesis of Alternating Polyisocyanate Copolymers by Anionic Polymerization for Mimicking Amphiphilic Helical Peptides

The amphiphilic conformation of α-helical peptides has important biological functions, such as ion transport, antifreeze, and innate immunity, which can be mimicked by alternating polyisocyanate copolymers. We synthesized poly(allyl isocyanate-alt-(S)-(-)-α-methylbenzyl isocyanate (P(AIC-alt-SMBIC)) and ammonium-containing P(AIC-alt-SMBIC) (N-P(AIC-alt-SMBIC)), ensuring the amphiphilic helical conformation. The benzyl group of SMBIC plays an important role in alternating copolymerization with its steric and electron-withdrawing effects, while AIC provides an alkene group capable of introducing a customized functional group. The P(AIC-alt-SMBIC) with predominantly alternating sequence was acquired at f_SMBIC /f_AIC =8 with a controlled molecular weight and narrow dispersity. N-P(AIC-alt-SMBIC)s were synthesized from thiol-ene radical addition with P(AIC-alt-SMBIC).

Clathrate Hydrate Inhibition by Polyisocyanate with Diethylammonium Group

Polymers containing amide groups have been used as kinetic hydrate inhibitors (KHIs). The amide group has good performance for hydrate nucleus adsorption, resulting in inhibition of hydrate growth. Polyisocyanates composed of an amide backbone can be KHI candidates; however, the use of polyisocyanates as KHIs has not yet been reported. Herein, we prepared water-soluble poly[3-[[2-(diethylamino)ethyl]thio]-1-propyl isocyanate-ran-hexyl isocyanate] (P(DETPIC-ran-HIC)) to investigate the ability of polyisocyanates to inhibit hydrate formation. In the tetrahydrofuran (THF) clathrate hydrate crystal growth inhibition tests, P(DETPIC-ran-HIC) showed better performance than the polyamide, poly(N-vinylpyrrolidone) (PVP).

Micellization Behaviour of Linear and Nonlinear Block Copolymers Based on Poly(n-hexyl isocyanate) in Selective Solvents

Block copolymers have attracted significant scientific and economic interest over the last decades due to their ability to self-assemble into ordered structures both in bulk and in selective solvents. In this work, the self-assembly behaviour of both linear (diblocks, triblocks and pentablocks) and nonlinear (miktoarm stars and a block-graft) copolymers based on poly(n-hexyl isocyanate), PHIC, were studied in selective solvents such as n-heptane and n-dodecane. A variety of experimental techniques, namely static and dynamic light scattering, dilute solution viscometry and atomic force microscopy, were employed to study the micellar structural parameters (e.g., aggregation number, overall micellar size and shape, and core and shell dimensions). The effect of the macromolecular architecture, the molecular weight and the copolymer composition on the self-assembly behaviour was studied. Spherical micelles in equilibrium with clusters were obtained from the block copolymers. Thermally stable, uniform and spherical aggregates were found from the triblock copolymers. The poly(n-hexyl isocyanate)-b-polyisoprene-b-poly(n-hexyl isocyanate),-HIH copolymers tend to adopt closed loop conformation, leading to more elongated cylindrical-type structures upon increasing the concentration. Clustering effects were also reported in the case of the pentablock terpolymers. The topology of the blocks plays an important role, since the poly(n-hexyl isocyanate)-b-polystyrene-b-polyisoprene-b-polystyrene-b-poly(n-hexyl isocyanate), HSISH terpolymer shows intermicellar fusion of spherical micelles, leading to the formation of extended networks. The formation of spherical micelles in equilibrium with clusters was obvious in the case of the miktoarm stars, whereas the block-graft copolymer shows the existence of mainly unimolecular micelles.

Biosignal-responsive polymer nanorods that specifically recognize hydrogen polysulfide (H2Sn) from reactive sulfur species

We report a new block copolymer bearing p-fluoronitrobenzoate (FNB) pendants that is capable of responding to the H₂S_n biosignal in an extraordinarily selective and sensitive manner.

Preparation of glycoside polymer micelles with antioxidant polyphenolic cores using alkylated poly(arbutin)s

This paper describes the synthesis of long-chain-alkylated poly(arbutin)s (poly(Arb)-R_x, where R = alkyl-chain length and x = degree of substitution (DS)) and their aqueous micelle formation.

Construction of reverse vesicles from pseudo-graft poly(glycerol methacrylate)s via cyclodextrin–cholesterol interactions

Reverse vesicles were constructed from pseudo-graft amphiphilic copolymers by dint of the host–guest inclusion complexation between β-cyclodextrins and cholesterols, and transformed into organogels by adding trace amounts of water.