| As one of the most common used film-forming materials, polyacrylate is widely used in leather finishing agent, textile adhesive, wood and construction paints due to its excellent gloss, flexibility, transparent and chemical stability. However, the drawback of neat polyacrylate, such as weak climate-resistance, poor antimicrobial activities and lower sanitation properties often restrict its application. Recently, polymer/inorganic nanocomposites have attracted a great deal of attention with the rapid development of nanotechnology.This research is based on the above background. Inorganic nanomaterials with excellent antimicrobial activities were bought into polyacrylte firstly. Then the influences of inorganic nanomaterials with different morphologies and sizes on the properties of the nanocomposites were investigated in details. At last, polyacrylate-based nanocomposites with excellent antibacterial and sanitation properties were obtained. The main contents are listed as follows.1. The effects of inorganic nanoparticles including commercially MgO, TiO2, ZnO, Al2O3, MMT and SiO2on the properties of the nanocomposites were investigated in details. Then anionic polymer (PA30) was used to modify the chosen ZnO, and the optimum modification conditions were obtained. At last, the preparation method and optimum conditions of polyacrylate/ZnO nanocomposites were studied.2. There are various ZnO nano structures with different shapes and sizes, and each of them displays some unique properties. ZnO nano structures with various morphologies and sizes were successfully obtained via microwave-assisted hydrothermal process in this study. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to investigate the morphology and crystal structure of obtained ZnO. Then polyacrylate/ZnO nanocomposite latexes were prepared by in-situ emulsion polymerization of acrylate monomers in the presence of PA30modified ZnO nanostructures. The influences of ZnO nano structures with various morphologies and sizes on the performances of the obtained ZnO, nanocompsite latexes and films, as well as the finished leather samples and treated fabrics were investigated.The results showed that the antimicrobial activities of sphere-like ZnO and polyacrylate/sphere-like ZnO nanocompsoite film were both decreased with the increasing of the diameter of ZnO.Sphere-like ZnO and flower-like ZnO had better antimicrobial activities and ultraviolet absorption property than those of ZnO with other morphologies. Polyacrylate-based films containing sphere-like ZnO and flower-like ZnO showed excellent antimicrobial activities on candida albicans. However, the antimicrobial activities of films containing sphere-like ZnO and flower-like ZnO on aspergillus flavus were poor.Experimental results showed that vapor permeability of the leather finished by polyacrylate/flower-like ZnO nanocomposite latex increased by232.65%, compared to that finished by pure polyacrylate latex. The moisture permeability of fabric treated by polyacrylate/sphere-like ZnO nanocomposite latex was increased by129.21%, compared to that treated by pure polyacrylate latex.The releasing of Zn ions and the photo catalysis activity of ZnO played an important role in the antimicrobial activities of polyacrylate/ZnO nanocomposite film containing sphere-like ZnO, and the excellent antimicrobial properties of polyacrylate-based film containing flower-like ZnO might attribute to the photo catalysis activity of ZnO.3. Ag particles were doped on the surface of sphere-like ZnO and flower-like ZnO to improve the antimicrobial activities of ZnO on aspergillus flavus. SEM, XRD and TEM were used to investigate the morphology, structure and chemical composition of the obtained composite particles. The influences of different methods including chemical and adsorption reduction method, microwave-assisted reduction method and oxidation-reduction method, and the morphologies of ZnO on the properties of the obtained ZnO/Ag composite particles were investigated. Then polyacrylate/ZnO/Ag nanocomposites were obtained by in-situ emulsion polymerization of acrylate monomers in the presence of PA30modified ZnO/Ag composite particles. The effects of ZnO/Ag composite particles with different preparation methods, morphologies, and the dosages of ZnO/Ag composite particles on the properties of the polyacrylate/ZnO/Ag nanocompsite latexes and films were investigated in detail. At last, the composite latex was used in leather finishing and textile treating.The results indicated that the antimicrobial activities of ZnO/Ag composite particles and polyacrylate/flower-like ZnO/Ag composite prepared by chemical and adsorption reduction method were higher than that prepared by microwave-assisted reduction method and oxidation-reduction method. Besides, the inhibition abilities to aspergillus flavus were greatly improved with the doping of Ag on the surface of ZnO.The antimicrobial activities of sphere-like ZnO/Ag composite particles and flower-like ZnO/Ag composite particles were almost alike. However, the antimicrobial activities of the film containing flower-like ZnO/Ag composite particles was higher than that of the film containing sphere-like ZnO/Ag composite particles.Experimental results showed the vapor permeability of the leather finished by polyacrylate/flower-like ZnO/Ag composite latex was increased by138.46%, compared to that finished by polyacrylate/flower-like ZnO composite latex. The moisture permeability of fabrics treated by polyacrylate/flower-like ZnO composite latex was increased by12.84%, compared to that treated by pure polyacrylate latex.The photocatalysis activites of ZnO/Ag composite particles played an important role in the antimicrobial activities of polyacrylate/flower-like ZnO/Ag nanocomposite film. The contaction of metal ions also influenced the antimicrobial activities of the nanocomposite film. However, the reason for the different antimicrobial activities on candida albicans and aspergillus flavus were probably due to the different structures and compositions of the two kinds of bacteria.Polyacrylate-based nanocomposites prepared by the above method had excellent antimicrobial and sanitation properties. The as-prepared composite film was soft but not sticky. Besides, the reaction was carried out in water media, which was non-toxic, pollution-free, and safe. There were few reports about the influences of inorganic nanomaterials with different morphologies and sizes on the properties of the nanocomposites, especially the antimicrobial activities. |
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