疏水化改性的介孔硅材料携带及释放纳米气泡能力的研究

发布时间：2018-12-26 08:21

【摘要】：纳米气泡最早是由Ishida等人将三氯十八烷基硅烷(OTS)修饰过的硅片直接浸入纯水中产生的,其存在已经通过多种实验手段得到证实,并成为界面科学研究的一个热点。研究表明,在有疏水表面存在的情况下,过剩气体分子倾向于直接在固体表面的成核中心(缺陷或空隙处)聚集,以纳米气泡的形式稳定存在于疏水固体与水的界面上。由于纳米气泡在界面上的稳定存在对表面科学、流体力学、生物医学及一些应用领域都有广泛的影响。因此,固/液界面纳米气泡的性质及应用方面都值得我们去探索研究,具有十分重要的理论意义和应用价值。在本文中,我们探究了纳米硅材料的疏水性能及表面物化性质的变化对其吸脱附纳米气泡能力的影响。具体内容如下:(1)本课题中,我们以聚环氧乙烷-聚环氧丙烷-聚环氧乙烷三嵌段共聚物(P123)为模板剂,通过双三乙氧基硅基乙烷在酸性条件下水解共聚,合成了乙基骨架的载体材料(PMO),然后再使用不同比例的六甲基二硅胺(HMDS)对其进行不同程度的疏水化改性,探究疏水化程度对PMO载体材料携带和释放纳米气泡能力的影响。实验结果表明,PMO型纳米硅材料可以有效吸附/脱附氧纳米气泡,并且在其他理化性质一致的情况下,随着疏水化程度的不断提高,其吸附氧纳米气泡的能力也随之提高,同时向缺氧环境中补充氧气的能力亦越强。(2)本课题中,我们以聚氧丙烯-聚氧乙烯共聚物(F127)为模板剂,由正硅酸四乙酯(TEOS)在酸性条件下水解共聚,再通过控制不同的进釜温度,制得了不同孔径和比表面积的无机骨架的载体材料(FDU),然后再使用过量的六甲基二硅胺(HMDS)对其进行疏水化改性,探究孔径和比表面积等物化性质对FDU载体材料携带和释放纳米气泡能力的影响。实验结果表明,FDU型纳米硅材料可以有效吸附/脱附氧纳米气泡,其能力与材料的比表面积和孔径有关。在疏水化程度一致的情况下,其吸脱附氧纳米气泡的速率与材料的孔径成正比,其吸脱附氧纳米气泡的含量与材料的比表面积成正比。
[Abstract]:Nanobubbles were first produced by Ishida et al., which were directly immersed in pure water by (OTS) modified with trichlorooctadecyl silane. Their existence has been confirmed by many experimental methods and has become a hot spot in the research of interface science. It is shown that in the presence of hydrophobic surfaces, the excess gas molecules tend to gather directly in the nucleation centers (defects or voids) of the solid surfaces, and exist stably in the form of nano-bubbles on the interface between the hydrophobic solids and the water. The stability of nano-bubble on the interface has a wide range of effects on surface science, hydrodynamics, biomedicine and some applications. Therefore, the properties and applications of nanoscale bubbles in solid / liquid interface are worthy of our exploration and study, which has very important theoretical significance and application value. In this paper, we investigate the influence of the hydrophobic properties and surface physicochemical properties of nano-silicon materials on the adsorption and desorption of nano-bubbles. The main contents are as follows: (1) in this thesis, we used poly (ethylene oxide), poly (propylene oxide) and poly (ethylene oxide) triblock copolymers (P123) as template, and hydrolyzed and copolymerized by bis (triethoxysilyl) ethane under acidic conditions. The support material of ethyl skeleton, (PMO), was synthesized and modified with different proportion of hexamethyldisilamine (HMDS) to different degree of hydrophobicity. To explore the effect of hydrophobicity on the ability of PMO carrier materials to carry and release nano-bubbles. The experimental results show that PMO nanocrystalline silicon can effectively adsorb / desorb oxygen nano-bubbles, and with the increase of hydrophobic degree, the ability of adsorption of oxygen nano-bubbles increases with the same physicochemical properties. At the same time, the ability of supplying oxygen to anoxic environment is stronger. (2) in this subject, we use polyoxypropylene polyoxyethylene copolymer (F127) as template, tetraethyl orthosilicate (TEOS) is hydrolyzed and copolymerized under acidic conditions. Then by controlling the temperature of the autoclave, the inorganic skeleton (FDU), with different pore size and specific surface area was prepared, and then modified by excessive (HMDS) of hexamethyldisilamine. The effects of physical and chemical properties such as pore size and specific surface area on the ability of FDU carrier to carry and release nano-bubbles were investigated. The experimental results show that FDU nanocrystalline silicon can effectively adsorb / desorb oxygen nano-bubbles, and its ability depends on the specific surface area and pore size of the material. When the degree of hydrophobicity is the same, the rate of adsorption and desorption of oxygen nano-bubble is proportional to the pore size of the material, and the content of the adsorbed oxygen nano-bubble is proportional to the specific surface area of the material.
【学位授予单位】：上海师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O613.72;TB383.1

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