Xinde Tang

Facile strategy for fabrication of transparent superhydrophobic coatings on the surface of paper

A one-step dip coating process was applied to fabricate a transparent superhydrophobic coating on the surface of paper using silica nanoparticles modified with long-chain hydrocarbon hexadecyltrimethoxysilane in an ethanolic solution.

Simple, robust and large-scale fabrication of superhydrophobic surfaces based on silica/polymer composites

Superhydrophobic surfaces were facilely fabricated by a brush coating process based on silica/polymer composites. The hydrophobicity of the obtained surfaces can be tuned by varying the weight ratio of silica/polymer. The simple and robust strategy can facilitate the fabrication of superhydrophobic surfaces in large-scale on general substrates.

A facile procedure to fabricate nano calcium carbonate–polymer-based superhydrophobic surfaces

A facile procedure to fabricate superhydrophobic surfaces based on nano calcium carbonate–polymer composites has been described. The hydrophobicity of the resulting surfaces can be tuned by varying the weight ratio of nano calcium carbonate–polymer composites. The simple and robust strategy can facilitate the fabrication of superhydrophobic surfaces on general substrates.

Thermo-sensitive zwitterionic block copolymers via ATRP

Novel thermo-sensitive zwitterionic ABC-type triblock copolymers poly(ethylene glycol)-block-[2-(methacryloyloxy)ethyl]dimethyl(3-sulfopropyl)-ammonium hydroxide-block-poly[2-(dimethylamino)ethyl methacrylate] (MPEG-b-PSBMA-b-PDMAEMA) were synthesized by atom transfer radical polymerization (ATRP). The bromide-terminated diblock copolymers poly(ethylene oxide)-block-[2-(methacryloyloxy)ethyl]dimethyl(3-sulfopropyl)-ammonium hydroxide (MPEG-b-PSBMA-Br) were prepared by the ATRP of methacryloxyethyl sulfobetaine initiated by the macroinitiator MPEG-Br, which was obtained by the esterification of poly(ethylene glycol) monomethyl ether (MPEG) with 2-bromoisobutyryl bromide. Then, poly(2-(diethylamino)ethyl methacrylate) (PDMAEMA) was introduced by a sequential ATRP process to obtain the triblock copolymers. These copolymers with varied compositions, molecular weights and polydispersities were characterized by 1H NMR and GPC. Variable temperature ultraviolet analysis was employed to test their stimuli-sensitive properties. These block copolymers exhibited distinct thermo-sensitivity under different molecular compositions or solution conditions. The resistance to the non-specific protein adsorption of the triblock copolymers was evaluated, and excellent antifouling property occurred. This can be attributed to surface hydration via hydrogen bonds between PEG and water molecules and the surface hydration via ionic-induction between PSBMA and water molecules. The synergistic effect resulted in an effective reduction of protein adsorption. These copolymers have potential applications as antifouling and antibacterial agents.

Biodegradable Self-Assembled Nanoparticles of Galactose-Containing Amphiphilic Triblock Copolymers for Targeted Delivery of Paclitaxel to HepG2 Cells.

Biodegradable self-assembled polymeric nanoparticles (NPs) composed of poly(6-O-methacryloyl-D-galactopyranose)-b-poly(L-lactide)-b-poly(6-O-methacryloyl-D-galactopyranose) (PMAGP-b-PLA-b-PMAGP) are prepared as carriers for the hydrophobic anticancer drug paclitaxel (PTX), to achieve target delivery to hepatoma cells. PTX can be encapsulated by the NPs with various molar ratios of L-lactide (LA) and 6-O-methacryloyl-D-galactopyranose (MAGP) during the process of self-assembly, and the resulting NPs exhibit high drug loading efficacy and substantial stability in aqueous solution. The size, size distribution, and morphology of the NPs are characterized using a Zetasizer Nano ZS and transmission electron microscopy. The hemolysis assay and cell cytotoxicity assay indicate that the polymeric NPs are biocompatible and non-toxic. The cellular uptake assay demonstrates that the galactose-containing NPs can be selectively recognized and subsequently accumulate in HepG2 cells. All of these results demonstrate that galactose-containing polymeric NPs are potential carriers for hepatoma-targeted drug delivery and liver cancer therapy in clinical medicine.

Electrosynthesis of pure poly(3,4-ethylenedioxythiophene) (PEDOT) in chitosan-based liquid crystal phase

Ordered poly(3,4-ethylenedioxythiophene) (PEDOT) was successfully prepared by electrochemical polymerization of 3,4-ethylenedioxythiophene in lyotropic liquid crystal phase formed by chitosan in an acetic acid solution. The structure, performance, and morphology of PEDOT were characterized by infrared absorption spectra, cyclic voltammograms, polarizing optical microscopy, and scanning electron microscopy. The ordered pure PEDOT film with good electrochemical behavior exhibited obvious birefringence.

Synthesis and water absorption of galactose-containing amphiphilic triblock copolymers based on PLAs

Well-defined amphiphilic triblock copolymers PMAGP-b-PLA-b-PMAGP with varied compositions and molecular weights were obtained via a four-step procedure. The hydrophilicity and water absorption increase with an increase of the PMAGP chain length. The presence of active hydroxyl groups was confirmed by a dyeing procedure.

Temperature-/CO2-dual-responsiveness of a zwitterionic “schizophrenic” copolymer

A zwitterionic “schizophrenic” copolymer with dual-responsiveness to temperature and carbon dioxide self-assembles to undergo a reversible phase transition in a weakly alkaline borate buffer solution. It can be switched “on” and “off” when sequentially treated with carbon dioxide/nitrogen (CO2/N2) due to the protonation–deprotonation of the tertiary amine groups along the polymer skeleton.