Jingcheng Liu,Ren Liu,Yan Yuan,Shengwen Zhang,Xiaoya Liu
Novel superhydrophobic antistatic coatings were prepared from the branched alternating copolymers P(St- alt -MAn) and carbon nanotubes through a facile method. Pristine multiwalled carbon nanotubes (MWCNTs) were non-covalently modified by an organic–inorganic hybrid of the branched copolymers P(St- alt -MAn) and silica with the existence of γ-aminopropyl-triethoxysilane. The modified MWCNTs were mixed with tetraethyl orthosilicate in ethanol, coated with a fluoroalkylsilane, and then heat treated to obtain the superhydrophobic antistatic coatings. Scanning electron microscopy (SEM) showed that the coatings have a micrometer- and nanometer-scale hierarchical structure similar to that of lotus leaves with high water contact angles (>170°). In addition, the relationship between content of MWCNTs and the properties of the coatings, as well as the effect of cure temperature on contact angle values were investigated systematically.
A new type of copolymer containing two alternating segments, poly-(styrene- alt -maleic anhydride)- co -poly (7-(4-vinylbenzyloxyl)-4-methylcoumarin- alt -maleic anhydride) P(St- alt -MAn)-co-P(VM- alt -MAn)(PSMVM), was prepared. The copolymer self-assembled into nanoparticles with internal microphase structures in water because the hydrophilicity of segment P(VM- alt -MAn) is higher than that of P(St- alt -MAn). The particle size, morphology, ζ potential and surface properties and their dependence on the pH and slat concentrations were studied with a combination of techniques. The nanoparticles of PSMVM showed surface activity and pH sensitivity for producing Pickering oil-in-water emulsions. The emulsion volume increased and the size of oil/water droplet decreased with increasing salt concentration. Furthermore, cross-linked nanoparticles (CLPs) were obtained by photo-dimerization of the pendent coumarin groups in PSMVM under UV irradiation. The emulsions produced by using the CLPs as emulsifiers showed even better stability upon standing. Solid oil-phase droplets were obtained by preparation of CLPs-stabilized Pickering emulsions with an oil phase of styrene containing the initiator AIBN followed by the polymerization of styrene. Thus, the enrichment and aggregation of the CLPs on the emulsion droplets was visible because the solid droplets remained unchanged during the SEM sample preparation.
Liu Jingcheng,Xiong Xiaomei,Liu Ren,Jiang Jinqiang,Liu Xiaoya
Novel branched alternating copolymers poly(styrene- alt -maleic anhydride) (BPSMA) were synthesized through free radical polymerization with styrene, maleic anhydride, and chain transfer monomer, 4-vinyl benzyl thiol. The successful synthesis of BPSMA was confirmed by a triple detection system including gel permeation chromatography, multiangle laser light scattering, and differential viscosity detectors, as well as thermal analysis (differential scanning calorimetry). This methodology proposes good prospects for scaling-up and thereby offers a wide range of branched alternating copolymers at low cost.
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