Study On Synthesis Of Inorganic/Organic Nanocomposite Materials And Hollow Materials

Nano-materials are the important aspects by the way of nano-science.In recent years,nano-materials have become the hot issue in the field of materials science.Nano-materials can be prepared by selective design and project ideas.Inthis paper,we report a new method to prepare the inorganic/organic nanocomposite materials and hollow materials wim different size and morphology by changingreaction measures and methods.In this paper, we prepared polystyrene microspheres with dispersion,emulsionpolymerization, and studied the effect of reaction temperature, monomer andmeasure of added monomer, the kinds and concentration of emulsifier and initiator,reaction medium on the polymerization process. The morphology, composition,weight loss, diameter, size and size distribution of polystyrene particles aremeasured by transmission electron microscopy (TEM), infrared spectra (FTIR),SEM, thermogravimetric analysis and Zetasizer analyzer. 3-(trimethoxysilyl)propyl methacrylate (KH570) is used as functional monomer, two different kindsof functional groups are concluded in it, ethylene groups of one end can becopolymered with other monomers; at the same time, silanol groups (SiOH) areincorporated on the surface of polystyrene latex particles because of trialkoxysilaneof the other end hydrolysis. As this principle, we described the synthesis ofpolystyrene core-shell particles carrying silanol groups on their surface bydispersion polymerization using the copolymerization between styrene and KH570in ethanol/water medium for the first time. We aim to produce hollow materialswith hydrophilic polystyrene latexes, which surface properties are similar to thoseof silica microspheres, and studied the effect of reaction time and reaction mediumon the core-shell particles. Emulsion of core-shell polymer was prepared in watermedium using traditional method, and emulsion cannot directly used materials aspreparing hollow spheres because hydrolysis and polycondensation of TEOS tookplace in ethanol medium. So it is necessary that emulsion must be centrifuged, anddispersed in ethanol. Reaction process of preparing core-shell polymer waspredigested with disperse polymerization in this paper. Core-shell polymerparticles can be directly used as materials preparing hollow spheres. We modified the inorganic nanoparticles using oleic acid and sodium oleate assurfactants. Surface energy of inorganic nanoparticles was reduced, and thecomparability between inorganic nanoparticles and polymers was enhanced.Oleic acid is a cheap unsaturation organic acid including carboxyl and C=C doublebonds functional groups. In this paper, we prepared silica particles using TEOS,ethanol, NH3·H2O and H2O as materials, controlled the total volume of reactionlatex 100 ml, studied the effect of the concentrations of TEOS and NH3·H2O,reaction temperature etc on the final products. We prepared a series of sphericalsilica with different diameters by changing the reaction condition, and obtained thehydrophobic silica using oleic acid as modifier. Oleic acid was bonded to the silicasurface with a single hydrogen bond between carboxyl functional groups andsilanol groups on the surface of nanosized silica. The presence of the oleic acid onthe surface modified silica was confirmed by the surface energy spectrum andFTIR spectroscopy. We prepared spinal and hexagonal modified magnesiumhydroxide particles using MgCl2·6H2O and NaOH as materials, sodium oleated asmodifier. The results indicated grafted Mg(OH)2 particles with spinal or hexagonalmorphology, diameters from 80nm to 200nm by transmission electron microscopy(TEM) and Zetasizer analyzer. We have prepared polystyrene/SiO2 composite particles (PSCP), poly (methylmethacrylate)/SiO2 composite particles (PMSCP), polystyrene/Mg(OH)2 compositeparticles (PSMCP) in situ emulsion polymerization. We prepared PSCP film. Wehave found the excellent comparability between inorganic particles and polymerwithout obvious interface. The method solves the difficult problem that inorganicparticles are difficult dispersion in the polymer; makes inorganic particles dispersewith nano-diameter grade in the film. We used inorganic particles with grafted oleicacid as "seed". Monomer was polymerized on the surface of inorganic particles,polymers were coated on the inorganic particles, which due to the C=C bondscopolymerization between oleic acid and monomer. So we obtainedinorganic/organic nanocomposite materials; aimed to produce materials withuniform distributable inorganic particles in the polymer latex. We studied the effectof the amount of monomer (St, Mma), grafted silica, modifier (OA), emulsifier(DBS), and imitator on polymerization process, morphology, diameter, size andsize distribution of composite particles. The diameters of PSCP can be increasedwith increasing the amount of styrene, and the thickness of the coating layer canalso be increased on the surface of silica particles. Polystyrene microsphereswithout silica appeared in the latex when the quality content of styrene is more than10%, and the size distribution of PSCP turns wide. It is seriously important thatmonomer drops without surface protecting cause the latex instability for short ofemulsifier. So the quality content of styrene must be less than 10%. Silica particlesin PSCP increased with increasing the grafted silica. When excessively increasedthe amount of grafted silica, the inorganic cannot be encapsulated entirely,separated from the latex in polymerization process, and adhibited on the wall ofbottle and the stirring pole. The quantity of latex particles was more when thequality of emulsifier increased, namely the concentration of emulsifier increased.The stability of latex decreased when emulsifier decreased, composite particleswith good dispersion were difficultly formed because of the decreasing emulsifieron the surface of latex particles. So in the synthesis systems, the appropriateamount of emulsifier is necessary in order to achieve colloid particles with goodmorphology, appropriate diameter and narrow size distribution. We selectedconcentration of emulsifier from 1–2.5mg/ml DBS. The morphology, composition,inorganic content, diameter, size and size distribution of composite particles aremeasured by transmission electron microscopy (TEM), infrared spectra (FTIR),SEM, thermogravimetric analysis and Zetasizer analyzer. It was in-situpolymerization method that inorganic particles were firstly dispersed in water,monomer was polymerized, then polymer/inorganic composite particles wereobtained. This method is simple, and the preparation of polymer/inorganiccomposite particles is widely attended by people. This nanocomposite method iscarried out in water, without changing the intrinsic polymerization route. So oncenanocomposite method is broken through, the character will make nano-materialsbe taken as the leader in industrializations. We prepared hollow spheres with nano-meter diameter by a new synthesismethod. Tradition method has the disadvantage of complex process and difficultcontrol, and aperture diameter of hollow sphere is hard to reach in the nano-size.This method is simple. A series of hollow spheres (such as hollow titania) can beprepared by this method. These results prove the novelty of this method, make usfurther understand the formation mechanism of macroporous materials. Weprepared functional KH570/PS polymer particles to covalently attach silanolgroups to the surface of polystyrene (PS) latex particles by a new dispersioncopolymerization between styrene and KH570. Adding ethanol solution includingTEOS into reaction latex, then the polycondensation reaction of TEOS exclusivelytook place on the particles surface in the presence of ammonia. Silica-coated...