Synthesis And Antifungal Properties Of Core-shell Particles Fe₂O₃/SiO₂

Mold is harm to the books and materials. The destructive force of the mold on the paper islarge and Mold is the most difficult to control. Mold has important influence on clay, bauxite,calcium carbonate and titanium dioxide pigment. Therefore, the pigment is modified to endowthem with certain mouldproof performance has important significance. γ-Fe₂O₃is a new type ofnanometer materials. It not only has the strong ultraviolet ray absorption, high chroma, hightinting strength, high transparency, but also non-toxic, tasteless, heat resistance, acid and alkaliresistant. It can be widely used in coating, paint, ink printing and chemical materials. In thispaper, γ-Fe₂O₃is modified and coated to synthesize with a certain nanocomposite of a certainantifungal properties.γ-Fe₂O₃is very easy to reunite in the decentralized system. In order to increase thesuperficial capacity of nanocrystalline iron oxide（γ-Fe₂O₃）, γ-aminopropyltriethoxylsilanecoupling agent （KH-550） was used via hydrolysis and condensation as modifier for surfacemodification of γ-Fe₂O₃. Using orthogonal experiment design, surface coupling claddingconcentration as the index was utilized to research effect of the coupling agent dilution agentdosage, reaction temperature, reaction time on the surface modification of γ-Fe₂O₃. Thesynthesized product was characterized by transmission electron microscope （TEM）, infraredspectrometer （FTIR）, Particle Size Analyzer. The optimum conditions were as follows:coupling agent concentration4.5%, reaction temperature55℃, reaction time6h. KH-550couldform chemical union with γ-Fe₂O₃. The agglomeration of γ-Fe₂O₃particles was effectivelyrestricted after surface modification. The average particle size was reduced by43.9%andparticle size distribution was more uniform with good dispersion.Core-shell structural γ-Fe₂O₃/SiO₂nanocomposite particles were prepared via hydrolysisand condensation of TEOS by using sol-gel method using TEOS as silica precursor.Orthogonal design and single factor experiment were utilized to study effect of seven factors onthe synthesis of nanocomposite particles, such as the dosage of γ-Fe₂O₃, Ammonia water,TEOS, the ratio of alcohol to water, reaction time, reaction temperature and stirring speed. Thesynthesized products were characterized by transmission electron microscope （TEM）, X-raydiffraction （XRD）, infrared spectrometer （FTIR）, differential scanning calorimetry （DSC） andParticle Size Analyzer. The results showed that the dosage of TEOS had the most influence onthe synthesis of Core-shell structural γ-Fe₂O₃/SiO₂nanocomposite particles. The optimum conditions were as follows: γ-Fe₂O₃0.06g, TEOS0.5mL, ammonia2mL, the ratio of alcohol towater5:1, reaction time8h, reaction temperature30℃and stirring speed150r/min. ComparedCore-shell structural γ-Fe₂O₃/SiO₂with γ-Fe₂O₃,The average particle size was reduced by31%and particle size distribution was more uniform, with good dispersion.By core-shell structure γ-Fe₂O₃/SiO₂nanocomposites on aspergillus Niger mouldproofperformance research, adding γ-Fe₂O₃/SiO₂in PDA medium, Aspergillus niger plaque diameteris an index To evaluate the antifungal effect. Experimental results of different adding methods,Influence of adding amount of γ-Fe₂O₃/SiO₂mouldproof performance, Influence ofhumidity conditions mouldproof performance and Comparison of different particle sizesmouldproof capabilities were studied. Studies have found that using the method of earlyadding γ-Fe₂O₃/SiO₂, adding the amount is larger, the smaller the relative humidity, theinhibitory effect of aspergillus Niger is better; Under the combined effect of particle size anddispersion properties, the average particle size is smaller, the better the dispersion, theinhibitory effect of aspergillus Niger is more significant; adding the same amount ofγ-Fe₂O₃/SiO₂, nano γ-Fe₂O₃, nano SiO₂into the medium, mouldproof effect order are: nanoSiO₂>γ-Fe₂O₃/SiO₂> nano γ-Fe₂O₃.