Meng Xu,Dong Yanyan,Arias Manuel J. Lis,Mu Song,Liang Liping
For the actual courses of surroundings conservation, segregation of oily water mixtures is increasingly desired. The hydrophobic/oleophilic cotton fabric as a system for removing oil from a water phase was prepared by reversible addition fragmentation chain transfer (RAFT) reaction technology. A piece of fabric was modified with the RAFT chain transfer agent S-1-Dodecyl-S′-(α′,α″-dimethyl-α″-acetic acid) trithiocarbonate (CTA), then hydrophobic/oleophilic interface was fabricated on the CTA modified fabric by grafting the octadecyl methacrylate. The chemical structures, surface topographies and surface properties were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and contact angle experiments, respectively. The ability of as-prepared fabric with a separation efficiency was better than 97.0 % on average for various types of oil/water mixtures demonstrated the hydrophobic/oleophilic property. We believe that the work will extend the applications of fabric in the oil/water separation and provide a new design in practical applications.
Poly(acrylated epoxidized soybean oil) (PAESO) has been grafted on the surface of multiwalled carbon nanotubes (MWCNTs) by reversible addition–fragmentation chain-transfer reaction (RAFT). MWCNTs–PAESO as reinforcement has been successfully applied to prepare epoxidized soybean oil/maleopimaric-based thermosetting composites with good dispersion through probe ultrasonic treatment in ethyl acetate. Micromorphology analyses on composites by transmission electron microscopy and scanning electron microscopy show that MWCNTs–PAESO has better dispersion stability in both ethyl acetate and epoxy matrix and better interface bonding effect with cured matrix, resulting in more uniformly and separately dispersed behavior than hydroxylated multiwalled carbon nanotubes. Correspondingly, by the method of molecular dynamics simulation, it is verified that the nonbond energy and van der Waals force of CNTs–PAESO in solvent can be relatively reduced, and that CNTs–PAESO possesses higher binding energy with matrix compared with CNTs OH. Therefore, MWCNTs–PAESO and PAESO have synergistic enhancement on the mechanical properties of composites demonstrated by rheology testing and dynamic mechanical analysis. The appropriate amount of MWCNTs–PAESO loading at 0.15 wt% can increase the glass transition temperature ( T g ) of thermoset from 83.8 to 96.3°C, resulting in the improvement of both mechanical and thermal properties. These results show that surface-grafting MWCNTs with homologous polymer can effectively increase the interfacial compatibility between matrix and MWCNTs, thereby improving the thermal and mechanical properties of composites.
Integrating these features of acid-activated positively charged surface and size contraction into single nanoparticle would be an effective strategy for enhancing cellular uptake, intratumoral penetration and accumulation. Here, hierarchical responsive micelle (HVDMs) was developed via RAFT reaction as multifunctional polymer-drug conjugate for maximizing penetration and therapeutic effect against MCF-7 tumor by combining positively charged surface with size contraction: surface zeta-potential reversal (−2 to +12 mV) by protonation of PHEME and size contraction (~81–~41 nm) by simultaneous hydrophobic/hydrophilic conversion (pH ≈ 6.7); the disintegration of hydrazone bond between hydrophobic PVB and DOX triggered drug release (pH ≈ 5.0). The in vitro structural stabilization, cellular uptake and anti-proliferative efficiency were significantly higher than other control groups (CVDMs and HSDMs) at pH 6.7. The markedly increased penetration depth, cellular internalization and anti-tumor efficiency were confirmed in 3D MCSs spheroids at pH 6.7, and the ex vivo DOX fluorescence images further verified obvious penetration and accumulation in internal region of solid tumor. The antitumor effect in vivo demonstrated that HVDMs accelerated tumor atrophy, induced intratumoral cells apoptosis and alleviated system toxicity.
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