Preparation And Properties Of Crystals With Large Unit

The crystallization behavior of crystals with large unit was different from thetraditional crystals which were consist of atoms, molecules or ions. Except theproperties of the unit itselef, there are many novel properties produced by thecoupling effect of units. Now, the study in crystals with large unit is still in incipientstage. In this paper, the films consisting of crystals with large unit were made withcolloids on plane substrates by spin-coating, even more, the phase transition betweenlayers was discussed. The co-assembly of a sacrificial colloidal template with a matrixmaterial were used to make SiO₂inverse opal, then the influence of photonic bandgap in inverse opal on the photoluminescence of fluorescence material wereinvestigated. On patterned substrates, we analyzed the peculiarity of crystallizationand finial structures when the ratio of unit size to the width of groove on substrate isdifferent. Subsequently, the crystals with large unit system which was used as anepitaxial growth model was made to assemble large unit colloids on photo etchingpatterned substrate through liquid circulation flow. The crystallization at differentexperiment conditions were studied. The main content and results achieved in thispaper are summarized as follows:1. Monodispersed colloids were assembled on glass slides by spin-coating method,and the optimum spinning speed and the phase transition between layers were bothdeliberated.2. Prepared SiO₂inverse opal by co-assembly method, then doped quinacrinedihydrochloride molecules in it using double substrate deposition. Then we discussedthe influence of photonic stop band in inverse opal on the photoluminescence propertyof fluorescence material.3. Assemble monodispersed PS and SiO₂colloids on CD substrate by spin-coating,the result reveals that units can disperse well on substrate when the surface andphysical properties between colloids and substrate is similarly. Then we assembleddifferent diameter PS colloids on CD through vertical lift-up method, the variousstructure pattern can be obtained because the ratio of groove width to PS diameter isdifferent.4. The ordered wrinkle structure which was induced by stress on PDMS substrate/Ptfilm system were made by mechanical stretch method. A series of different wavelength wrinkle system were obtained by regulating the thickness of Pt films.Then different organized results were gotten through lifting up same diameter PScolloids on different wavelength wrinkle system.5. The prefabricated structures on ITO conducting glass/negative photoresistsubstrate were made by photolithography, and the mechanic wriggle were used asdriving power, mono-disperse PS colloidal suspension flow circularly onphoto-etching patterned substrate, then the crystallization at different experimentcondition were studied.