Silica nanospheres (SNSs) synthesized with different base catalysts assemble into one-dimensional (1D) chain-like nanostructures at proper pH levels in the presence of the block copolymer F127. The addition of basic amino acids or the removal of base catalysts by dialysis influences the pH of 1D assembly. The base molecules affect assembly by modifying the electrostatic repulsion among the SNSs; however, they are not indispensable for this 1D assembly phenomenon.
A facile approach is demonstrated for the preparation of hollow mesoporous silica nanoparticles with large pore volume and high dispersibility. Core–shell nanoparticles consisting of iron oxide (α-Fe2O3) core and mesostructured silica–surfactant composite shell are treated with hexamethyldisiloxane under acidic conditions to achieve capping of silanol groups and removal of both surfactants and the Fe2O3 cores in a single step.
In this study, phase changes, catalytic active species that appeared at the phase change, and the corresponding water tolerance of samples obtained upon thermal treatment from K2CO3-supported microsized and nanosized sodalite as diesel-soot combustion catalyst are examined. We have shown the successful preparation of nepheline with water tolerance from sodalite as starting material. It is confirmed that the interaction between alkali metal carbonate and crystalline aluminosilicate is prerequisite for enhancing water tolerance of the catalytically active component, Na/K carbonate, located on the nepheline.