放射状褶皱结构介孔二氧化硅负载纳米银的制备及其抗菌性能研究

发布时间：2018-06-17 20:25

本文选题：放射状褶皱结构 + 介孔氧化硅　；参考：《深圳大学》2015年硕士论文

【摘要】：纳米银具有很强的吸附性,表面能和化学活性,可吸附细菌使其失去活性而死亡。但是,随着尺寸的减小,纳米银在实际应用中分散性差、缓释过快、且不易保存,将银纳米粒子(Ag NPs)均匀负载到结构更为稳定的无机纳米载体上,预计能顺利解决上述难题。介孔氧化硅材料生物相容性好、比表面积大,化学修饰性和稳定性较好,在催化,药物控释,基因治疗等领域应用广泛。本文利用原位化学还原将Ag NPs负载到具有丰富管道的放射状褶皱结构介孔二氧化硅材料内外表面。这种新型结构介孔二氧化硅的负载性、容纳性及可修饰性优于传统介孔氧化硅。首先,向外开放的放射状结构能让各种尺寸的客体通过并进入到内层,利于银纳米粒子的负载,增强纳米银的分散稳定性能,并保证了单位体积内纳米Ag的密集分布。同时,Si O2球壳对镶嵌在其内表面上的纳米Ag起到保护作用,降低其消耗速度。最后,多重尺度介孔的协同结合将在纳米Ag逸出抗菌性能中充当缓释基体,延长所得纳米抗菌剂的使用寿命。本文的主要实验路线是以分别修饰有巯基、氨基以及羧基活性基团的放射状褶皱结构介孔氧化硅为载体,利用官能团与Ag+的结合能力,有效调控介孔氧化硅内外表面的银离子浓度以及分布。接着,通过对吸附的银离子进行原位还原,即可制得载银纳米介孔二氧化硅材料。最后,我们对此材料的抗菌性能进行了详细的表征,具体工作分为以下几个部分:(1)放射状褶皱结构介孔氧化硅载体的制备及表征。碱性环境下,以十六烷基三甲基溴化铵(CTAB)为模板剂,正硅酸乙酯(TEOS)和3-巯丙基三甲氧基硅烷(MPS)为硅源,乙醚为增溶剂,室温条件下采用溶胶-凝胶法改变MPS添加量,合成一系列具有放射状褶皱结构的介孔氧化硅。其中,MPS/TEOS体积比=0.08时所得样品形貌规整,粒径均一,约为100 nm左右,比表面积可达696.59 m2/g;(2)对以上制得的巯基改性介孔氧化硅进行磺化处理,利用静电作用吸附Ag+,将其固定在介孔氧化硅整个表面,再将其原位还原。所得纳米Ag在介孔氧化硅表面分布密集且均匀,粒径只有3~5 nm,无团聚现象,对大肠杆菌和金黄色葡萄球菌均表现出优异的抗菌性。样品对大肠杆菌的MIC为36.55 mg/L,MBC为48.55 mg/L,对金黄色葡萄球菌的最小抑菌浓度(MIC)为73.10 mg/L,MBC为97.10 mg/L,其中银的负载量仅8.32%;(3)制备氨基、羧基改性放射状褶皱介孔氧化硅,利用氨基和羧基的配位能力吸附Ag+,固定其在介孔氧化硅表面的分布,再原位将Ag+还原成Ag NPs,有效解决了Ag NPs易团聚问题。测试结果表明:Ag NP@Si O2-NH2中纳米Ag颗粒分布密集均匀,粒径约10nm,而Ag NP@Si O2-COOH中纳米Ag分布稀疏,粒径较大,约20~30 nm。N-Ag对大肠杆菌和金黄色葡萄球菌的抗菌能力均远胜于C-Ag的抗菌能力。
[Abstract]:Silver nanoparticles have strong adsorbability, surface energy and chemical activity. However, with the decrease of size, the dispersion of silver nanoparticles in practical applications is poor, the slow release is too fast, and it is not easy to preserve. It is expected that the above problems can be solved by loading silver nanoparticles with Ag NPs evenly onto inorganic nano-carriers with more stable structure. Mesoporous silica materials have good biocompatibility, large specific surface area, good chemical modification and stability, and are widely used in catalysis, drug controlled release, gene therapy and so on. In this paper, Ag NPs were loaded into the inner and outer surfaces of porous silica materials with radial fold structure with abundant pipes by in situ chemical reduction. This new type of mesoporous silica is superior to traditional mesoporous silica in its load-carrying, accommodative and modifiable properties. Firstly, the radial structure which is open to the outside can make the objects of various sizes pass through and enter the inner layer, which is favorable to the loading of silver nanoparticles, enhance the dispersion and stability of silver nanoparticles, and ensure the dense distribution of nano-Ag in unit volume. At the same time, the spherical shell of SiO2 can protect the nano-Ag embedded on its inner surface and reduce its consumption speed. Finally, the synergistic combination of multi-scale mesoporous will act as the slow-release matrix in the antibacterial properties of nano-Ag escape, and prolong the service life of the prepared nano-antibacterial agent. In this paper, the main experimental route is to utilize the binding ability of functional groups to Ag by using mesoporous silicon oxide with radial fold structure modified with sulfhydryl, amino and carboxyl active groups, respectively. The concentration and distribution of silver ions on the inner and outer surfaces of mesoporous silica were effectively regulated. Then, the silver loaded nano mesoporous silica material can be prepared by in situ reduction of the adsorbed silver ions. Finally, the antibacterial properties of this material were characterized in detail. The specific work was divided into the following parts: 1) preparation and characterization of mesoporous silicon oxide carrier with radial fold structure. In alkaline environment, cetyltrimethylammonium bromide (CTAB) as template, tetraethyl orthosilicate (TEOS) and 3-mercaptopropyltrimethoxysilane (MPS) as silicon source, ether as solvent, and sol-gel method were used to change the amount of MPs at room temperature. A series of mesoporous silicon oxide with radial fold structure was synthesized. When the volume ratio of MPS / TEOS was 0.08, the sample was uniform in shape, about 100nm in size, with a specific surface area of 696.59 m2 / g ~ (-2). The sulfhydryl modified mesoporous silica was sulfonated, and Ag was adsorbed by electrostatic interaction. It is immobilized on the whole surface of mesoporous silica and then reduced in situ. The nanocrystalline Ag was distributed densely and uniformly on the surface of mesoporous silica with a particle size of only 3 ~ 5 nm without agglomeration. It showed excellent antibacterial activity against Escherichia coli and Staphylococcus aureus. The MIC of the sample to Escherichia coli was 36.55 mg / L MBC was 48.55 mg / L, and the minimum inhibitory concentration to Staphylococcus aureus was 73.10 mg / L MBC = 97.10 mg / L, in which the loading amount of silver was only 8.32 mg / L) to prepare amino, carboxyl modified radial fold mesoporous silicon oxide. Using the coordination ability of amino and carboxyl groups to adsorb Ag, to fix the distribution of Ag on mesoporous silica surface, and then to reduce Ag in situ to Ag NPs, which effectively solves the agglomeration problem of Ag NPs. The results showed that the distribution of nano-Ag particles was dense and uniform, and the particle size was about 10nmm. the distribution of nano-Ag in Ag NPSiO2-COOH was sparse and the size of nano-Ag was larger. The antibacterial ability of about 200.30nm.N-Ag against Escherichia coli and Staphylococcus aureus was much better than that of C-Ag.
【学位授予单位】：深圳大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ131.22;TB383.1

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