纺锤形二氧化硅胶体粒子的制备及组装OA

Anisotropic spindle-shaped silica colloidal particles(SSCPs)with tunable geometrical parameters and sizes were synthesized via a segmented,temperature-controlled microemulsion method.Scanning electron microscopy(SEM)characterization results showed that the SSCPs possess a uniform spindle-like morphology with a thicker middle segment and two thinner ends.Using these SSCPs as building blocks,colloidal liquid crystals were assembled driven by shape entropy via gravity sedimentation in a capillary.The resulting structures included smectic,nematic,and isotropic phases.A phase diagram was constructed with the total length(L)of SSCPs as the horizontal axis and the end-to-center diameter ratio(De/Dc)as the vertical axis.When L>1.31 μm and De/Dc<0.72,the formation of the smectic phase was effectively suppressed,and the nematic phase was preferentially induced.