【摘要】：球形納米銀具有良好的廣譜抗菌性和高安全性。其形貌和尺寸分布是影響其物理化學(xué)性質(zhì)和功能的主要因素,因此納米銀的可控制備是近年來研究的熱點(diǎn)方向之一。本論文采用液相化學(xué)還原法,以來源廣泛、無毒的天然產(chǎn)物殼聚糖為保護(hù)劑,葡萄糖為還原劑,硝酸銀為銀前驅(qū)體,研究了在水相中制備球形納米銀的影響因素,探討了可控制備球形納米銀的方法,并考察了球形納米銀的抗菌性能。本論文對液相化學(xué)還原法的反應(yīng)條件進(jìn)行了一系列單因素實(shí)驗(yàn),采用紫外可見光譜儀、透射電子顯微鏡和x射線衍射等技術(shù)確定了各反應(yīng)條件對球形納米銀制備過程的影響,并優(yōu)化了制備工藝。反應(yīng)體系處于弱堿性(pH=7.30～8.30),反應(yīng)溫度為60℃,殼聚糖/AgNO3質(zhì)量比為980,AgNO3濃度0.01～0.04 mol/L, AgNO3/葡萄糖摩爾比為1,反應(yīng)時(shí)間8h時(shí)有利于生成單分散、小尺寸的穩(wěn)定球形納米銀膠體。FTIR光譜表明殼聚糖對球形納米銀的保護(hù)主要源于分子中-NH2中的N與銀原子進(jìn)行配位,使球形納米銀不易團(tuán)聚沉降。本研究發(fā)展了一種操作簡單、在水相中可控合成球形納米銀的方法。通過向液相還原體系中引入不同尺寸的球形納米銀為晶種,合成了一系列尺寸均一的球形納米銀。在制備過程中,發(fā)現(xiàn)隨著加入的晶種粒徑的增大,制備的球形納米銀粒徑同步增大,可以從6 nm、9 nm、12 nm依次遞增至25 nm,說明在晶體生長過程中保持銀原子處于較低濃度是尺寸可控合成的關(guān)鍵。采用Optical Density 600法研究了球形納米銀的抗菌性能。發(fā)現(xiàn)球形納米銀對金黃色葡萄球菌(S. aureus)口大腸桿菌(E. coil)都具有優(yōu)異的抗菌性能,尤其是針對E. coil。在相同球形納米銀濃度下,其抗菌性隨著其粒徑的增加而迅速降低,小粒徑球形納米銀具有更強(qiáng)的抗菌性；對同一種細(xì)菌,同一粒徑的球形納米銀的抗菌性隨著銀含量的提高迅速提高。與自制的PVP-球形納米銀、AgNO3和殼聚糖相比,以殼聚糖為保護(hù)劑的球形納米銀抗菌性最優(yōu)。
[Abstract]:Spherical silver nanoparticles have good broad-spectrum antibacterial properties and high safety. The morphology and size distribution are the main factors affecting the physical and chemical properties and functions of silver nanoparticles, so the controllable preparation of silver nanoparticles is one of the hot research directions in recent years. In this paper, the liquid phase chemical reduction method was used to study the factors influencing the preparation of spherical silver nanoparticles in aqueous phase with chitosan, a non-toxic natural product, as protective agent, glucose as reducing agent and silver nitrate as precursor. The method of controllable preparation of spherical silver nanoparticles was discussed, and the antibacterial properties of spherical silver nanoparticles were investigated. In this paper, a series of single-factor experiments were carried out on the reaction conditions of liquid-phase chemical reduction method. The effects of the reaction conditions on the preparation of spherical silver nanoparticles were determined by UV-Vis spectroscopy, transmission electron microscope and X-ray diffraction. The preparation process was optimized. The reaction system is in weak basic (pH=7.30~8.30), the reaction temperature is 60 鈩，

本文編號：2185040