Preparation and Surface Modifing Application of Functional Silica Nanoparticles and PMAA Nanoparitcles

Author:Zhao Zheng Bai

Supervisor:jiang yong


Degree Year:2017





A easy way to prepare the functional nanomaterials was demonstrated in this paper.A facile and effective method to fabricate raspberry-like nanoparticles is reported in a one-pot reaction.This method consists of two steps:preparation of silicananoparticle precursors dispersion via the Stoberprocess and growth of the tiny functionalfluoride-silicananoparticles on the surface of silica nanoparticle precursors via the hydrolysis-condensation reaction of tetraethoxysilane(TEOS)and 1H,1H,2H,2H-Perfluorodecyl triethoxysilane(HDFTES).The obtained raspberry-like nanoparticle dispersion could be spraycoated onto differentsubstratesdirectly with the water contact angle greater than 150° and water roll-off angle less than 4°.And the prepared coatings maintained water resistance after water jetting,sand abrasion.This method can be an effective strategy for fabricating superhydrophobic surfaces for practicalindustrial applications.Based on the previous research,a facile and effective method to fabricate hybrid nanocomposites for amphiphobic coatings is reported in a one-step reaction.The F-Si@PMAA hybrid nanocomposites with rough dual structure were prepared via the co-condensation reaction of tetraethoxysilane(TEOS)and 1H,1H,2H,2H-Perfluorodecyl triethoxysilane(HDFTES)on the surface of the pre-synthesized PMAA nanoparticles in ethanol dispersion.The resulting hybrid nanocomposites dispersion could be spray coated onto different substrates directly.All the coated substrates exhibited good amphiphobicity that superhydrophobicity with the water contact angle greater than 1500° and water roll-off angle less than 4° and high oleophobicity with the oil contact angle greater than 130°.Moreover,the prepared coatings maintained water resistance after water jetting,sand abrasion.This method can be an effective strategy for fabricating amphiphobic surfaces for practical industrial applications.The kind of silicone coupling agent was changed in the experiment,a multi-layer core-shell nanoparticle with multiple functions also could be prepared by a two-step process.First,the hydrolysis-condensation reaction of 3-methacryloxypropyl trimethoxysilane(MPS)and tetraethoxysilane(TEOS)was performed on the surface of the pre-synthesized SiO2 nanoparticles to form the MPS/SiO2 core-shell nanoparticles.Second,the copolymerization of octadecyl methacrylate(ODMA)monomers with C=C bonds was carried out on the surface of MPS/SiO2 nanoparticles to form PODMA/MPS/SiO2 multi-layer nanocomposite.The hybrid nanocomposite could be used directly as the thermostable hydrophobic coatings.The prepared coatings not only were hydrophobic with the water contact angle greater than 130°,but also exhibited high heat resistance.Moreover,the hybrid nanocomposite could also be used as nano viscosity depressants for crude oil.The viscosity of crude oil could be reduced more than 80%.Owing to these good practical advantages,the PODMA/MPS/SiO2 hybrid nanocomposites may have some potential applications in practical industrial production.Based on the results of the previous experiments,a system of different siloxane@ poly(methylacrylic acid)core-shell nanoparticles with functional groups were prepared by the previous facile hydrolysis-condensation method in this work.Three different silane coupling agents 3-methacryloxypropyltrimethoxysilane(MPS),3-triethoxysilylpropylamine(APTES),3-glycidoxypropyltrimethoxy silane(GPTMS)were added along with tetraethoxysilane(TEOS)into the polymethylacrylic acid(PMAA)nanoparticles ethanol dispersion to form the Si@PMAA core-shell nanoparticles with different functional groups.The core-shell structure and the surface special functional groups of the resulting nanoparticles were measured by TEM and FTIR.The corresponding preparation conditions and mechanism were discussed in detail.This hydrolysis-condensation method also could be used to functionalize other nanoparticles which contain active groups on the surface.Meanwhile,the Si@PMAA core-shell nanoparticles with carbon-carbon double bonds and amino groups have further been applied to prepare hydrophobic coatings.