pH responsive polymeric Janus nanosheets with poly（maleic acid） moiety and crosslinked PS onto the corresponding sides have been synthesized by free radical polymerization. The Janus nanosheets can serve as solid emulsifier to stabilize an oil/water emulsion, whose stability is easily triggered by changing pH across pKa of the poly（maleic acid）.
Peng ZhouQian WangCheng-Liang ZhangFu-Xin LiangXiao-Zhong QuJiao-Li LiZhen-Zhong Yang
We herein report a novel approach to fabricate poly（DVB-co-VBC） one-dimentional nanomaterials with varied composition. By adjusting the monomer DVB/VBC ratio and using inert solvents, after internal cavity of the nanotubes disappears and length of the nanotubes is decreased, thus nanorods are achieved. After quaternary ammoniation from the benzyl chloride group, the exterior surface becomes hydrophilic while the interiority preserves hydrophobic. The Janus nanorods can serve as a specific vehicle to selectively collect oils from their aqueous surroundings.
The influence of chirality on the thermal conductivity of single-walled carbon nanotubes （SWNTs） is discussed in this paper, using a non-equilibrium molecular dynamics （NEMD） method. The tube lengths of the SWNTs studied here are 20, 50, and 100 nm, respectively, and at each length the relationship between chiral angle and thermal conductivity of a SWNT is revealed. We find that if the tube length is relatively short, the influence of chirality on the thermal conductivity of a SWNT is more obvious and that a SWNT with a larger chiral angle has a greater thermal conductivity. Moreover, the thermal conductivity of a zigzag SWNT is smaller than that of an armchair one. As the tube length becomes longer, the thermal conductivity increases while the influence of chirality on the thermal conductivity decreases.
pH responsive composite Janus cages of PS-silica-PEO are prepared using silica nanoparticles to crosslink two PAA contained di-block copolymers at an emulsion interface sequentially. Transverse channels are in situ created across the shell, which facilitates mass transfer. Shell is pH responsive owing to the presence of residual PAA chains tethered onto the silica nanoparticles. The Janus cages are capable to preferentially capture oil from their aqueous surroundings. The saturation absorption capacity is determined by pH and oil property. Other composite Janus cages are expected by extension the method using other copolymers and functional nanoparticles.
