Responsive nanotubular organo-gelator

Sulfonated polydivinylbenzene bamboo-like nanotube stabilized Pickering emulsion for effective oxidation of olefins to 1,2-diol

Sulfonated polydivinylbenzene bamboo-like nanotube (SPDVB) with effective olefins oxidation activity is prepared by combining cationic polymerization and sulfonation. By merely adjusting sulfonation time, SPDVB with different sulfonic acid group (-SO₃H) contents is achieved. SPDVB is used as both a solid emulsifier and catalyst to fabricate Pickering emulsion interface catalytic system for oxidizing olefins with 30% H₂O₂ acting as oxidant/water phase and olefins acting as reactants/oil phase. It is shown that Pickering emulsion interface catalytic system stabilized by SPDVB exhibits enhanced olefins oxidation efficiency than the conventional ones. At the optimum catalyst and reaction condition, the conversion of olefins by Pickering emulsion interface catalytic system stabilized by SPDVB for cyclohexene, 1-methylcyclohexene, cyclooctene, 2,3-dimethyl-2-butene oxidation is higher than 90.00% and the corresponding 1,2-diol selectivity exceeds 93.00% except the selectivity to 1-methyl-1,2-cyclohexanediol. The catalytic system also exhibits excellent cycling performance (>95.00% olefins conversion and >89.00% 1,2-diol selectivity for cyclohexene/2,3-dimethyl-2-butene oxidation after four cycles). A possible mechanism for oxidation of olefins to 1,2-diol by SPDVB stabilized Pickering emulsion is proposed: the high catalytic interface area between sulfonic acid group and H₂O₂ in water phase enhances the sulfonic acid group of SPDVB to convert into peroxysulfonic acid (catalytic activity centre) firstly; then the formed peroxysulfonic acid attacks the double bond of olefins to form epoxide intermediates, which will be hydrolyzed to 1,2-diol.

Tadpole-like Janus nanotubes

Tadpole-like Janus nanotubes with controlled size are fabricated by a sol-gel reaction at the emulsion interface. Pd or Fe3O4 nanoparticles can be selectively captured into their cavities to obtain tadpole-like Janus Pd-nanotubes or tadpole-like Janus Fe3O4-nanotubes. They can be driven directionally by a chemical fuel or near-infrared (NIR) light.

Poly(alkoxysilane) reusable organogels for removal of oil/organic solvents from water surface

Novel poly(alkoxysilane)s with high oil and organic solvent absorbencies were prepared by a bulk polymerization technique via the condensation of 1,3-benzenedimethanol with different lengths of alkoxysilanes at 160 °C without using a catalyst. The influence of the length of the alkoxysilane on the polymer properties and swelling ratios was investigated. Swelling experiments in various solvents indicated that these cross-linked poly(alkoxysilane)s can be used as absorbents for oils and oil-derived organic solvents. The swelling features of the poly(alkoxysilane)s were determined by solvent absorption tests, swelling kinetics experiments, and desorption kinetics measurements. The absorption capacities of the poly(alkoxysilane)s were 50-725% for various organic solvents and oil derivatives such as gasoline and diesel. The structural and thermal properties of the cross-linked poly(alkoxysilane) polymers were determined by FTIR, solid-state (13)C and (29)Si cross-polarization magic angle spinning (CP-MAS) NMR, and thermal gravimetric analysis (TGA).

A hierarchical rippled and crumpled PLA microstructure generated through double emulsion: the interesting roles of Pickering nanoparticles

The delicate roles of Pickering nanoparticles for the in situ creation of hierarchical rippled and crumpled textures upon biomedical polymers were uncovered and demonstrated.