Janus Nanospheres Were Prepared Based On The Optical Activity Of Organic Siloxane

Janus particles with two sides in morphology or properity has attracted increasing interest because of their unique properties based on additional orientation interactions and potential applications in a number of fields, such as functional surfactants, self-assembly and molecular recognition, electronic paper, optical biosensors, multifunctional magnetic asymmetric materials, refection reducing coating, electronic device, photonic crystal, catalyst, and anisotropic building blocks for supraparticular assemblies.A simple method to prepare Janus particle was proposed in this thesis. The method was based on selective irradiation of SiO2 particles with photoactive alkoxysilane. The prepared particles possess two sides in polarity, which makes the particles have Janus particles property. To meet the desired aim, the following contents are involved in this thesis:(1) Synthesis characterization of photosensitive silane NVOC-U-PTEOS by reaction between 6-Nitroveratryl oxycarbonyl alcohol (NVOC-OH) with isocyanatopropyl-triethoxysilane (NCO-PTEOS)(2) Preparation and characterization of silica particles by the stober method.(3) Synthesis and characterization of silica modified NVOC-U-PTEOS by condensation between hydroxy in silica and OCN in NVOC-U-PTEOS.Based on the experiments mentioned above, the following results were obtained.(1) The reaction between NCO-PTEOS and NVOC-OH can be employed to get NVOC-U-PTEOS. For this reaction. Keeping dried reaction environment is very important. Additionally, to remove THF in precipitation of the production is very important also. The IR and 1HNMR results indicated that the obtained produce makes the composition of NVOC-U-PTEOS. The UV spectroscopy results indicated that NVOC-U-PTEOS can be degradation to form compounds with NH2 and aldehydic groups respectively. Namely, NVOC-U-PTEOS possesses photoactivity.(2) The results from preparation of the silica and the modified silica easily to immobilize NVOC-U-PTEOS onto surface of the silica.(3) The method for preparation of Janus silica with different polarity in two sides was proposed. The modified silica particles with photoactivity were placed in two quartz plates in one side, by which one half surfaces of the modified silica particles with photoactivity. Could be photo-degradation. Based on this method, the Janus silica particles with polar and apolar surface could be obtained. The irradiation of silica particles were characterized by TEM and the dispersion in water/organic solvent. The results indicated that the irradiated silica particles with photoactivity can selectively absorb the carboxylic acid-modified gold particles in one side of the silica particles, indicating that the irradiated silica particles with photoactivity have a side with NH2 and a side with hydrophobicity. The dispersion of the irradiated particles in water/organic solvent illustrated that the particles are distributed at interface of water and organic solvent. The result showed that the irradiated particles have amphiphilic performance.