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  本文選題：銀納米粒子　切入點：(Ag/Ag~+/Ag~(3+))復(fù)合納米粒子　出處：《陜西科技大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：銀納米顆粒(AgNPs)及其復(fù)合納米顆粒具有優(yōu)異的導(dǎo)電性能、良好的抗菌性、小尺寸效應(yīng)及量子尺寸效應(yīng)等,使其廣泛應(yīng)用于醫(yī)療、電子、食品等行業(yè)。AgNPs的制備方法主要有物理法,化學(xué)法和生物法。與物理法和化學(xué)法相比,生物法因具有高效、快速、簡單易行、環(huán)境友好及價格低廉等諸多優(yōu)點而倍受人們關(guān)注。目前微生物法研究較多,植物法卻鮮為報道,為了開拓新的AgNPs及復(fù)合NPs的植物制備法,本研究選取綠茶、銀杏葉、蘋果渣及石榴皮提取液為還原劑和穩(wěn)定劑合成AgNPs及其復(fù)合NPs。主要研究內(nèi)容及其結(jié)果如下:(1)綠茶、銀杏葉、蘋果渣、石榴皮等植物水提取液與AgNO_3溶液混合,制備AgNPs或(Ag/Ag~+/Ag~(3+))NPs;借助UV-vis、XRD和TEM等儀器對所得納米粒子進行表征,利用FTIR分析檢測植物提取液合成納米粒子前后含有的大分子物質(zhì)變化;通過單因素實驗確定了植物法合成AgNPs及其復(fù)合物的適宜條件。結(jié)果表明:以綠茶提取液為原料,合成條件為:料液比1:30(g/mL),AgNO_3濃度為10 mmol/L,反應(yīng)液體積比為1:5(mL/mL),所得AgNPs的平均尺寸為13.6 nm;以蘋果渣提取液為原料,合成條件為:料液比1:20(g/mL),AgNO_3濃度為15 mmol/L,反應(yīng)液體積比為1:4(mL/mL),得到平均尺寸為16.0 nm的AgNPs;且這兩種植物提取液合成的AgNPs結(jié)晶度較高,形貌規(guī)整,呈球形或近似球形,大小均勻,顆粒分散。以銀杏葉提取液為原料,合成條件為:料液比1:50(g/mL),AgNO_3濃度為5 mmol/L,反應(yīng)液體積比為1:8(mL/mL),制備的(Ag/Ag~+/Ag~(3+))NPs均勻分散結(jié)晶度較高,為球形或近似球形,其中AgNPs的平均尺寸為13.8 nm,AgONPs的平均尺寸為24.6 nm;以石榴皮提取液為原料,得到(Ag/Ag~+/Ag~(3+))NPs,合成條件為:溶液pH=8,AgNO_3濃度為10 mmol/L,料液比為1:15(g/mL),得到的復(fù)合NPs較分散,結(jié)晶度較好,尺寸分布在18~35 nm之間;FTIR分析表明,植物提取物中的多酚類,黃酮類,維生素,蛋白質(zhì)等大分子物質(zhì)在納米粒子的形成過程起還原和保護作用。(2)以Vc作為對比,測定了植物水提取物對·OH、O_2~-·及DPPH自由基的清除率,確定提取物抗氧化性的強弱;測定了合成條件下Ag~+的還原率;測定了研究所得AgNPs在溶液中的穩(wěn)定性。結(jié)果表明,綠茶提取液的抗氧化性強于Vc,對自由基有很強的清除能力,其余3種植物提取物的稍弱;植物提取物對4種自由基清除率的實驗結(jié)果表明,綠茶、銀杏葉等被選取的4種植物提取物對DPPH自由基的清除效果最好;通過測定可得Ag~+的還原率或轉(zhuǎn)化率均可達到99%以上;合成的AgNPs在溶液中較穩(wěn)定。(3)利用抑菌圈法和MIC值檢驗了合成的AgNPs及(Ag/Ag~+/Ag~(3+))NPs對E.coli和S.aureus的抑菌性能,結(jié)果表明,AgNPs對革蘭氏陽性菌和革蘭氏陰性菌的生長均有較好的抑制能力,且(Ag/Ag~+/Ag~(3+))NPs的抑菌能力約是AgNPs的2~3倍;AgNPs或(Ag/Ag~+/Ag~(3+))NPs對E.coli和S.aureus的MIC值約為1.15×10~(-4) mol/L或約為2.90×10~(-5) mol/L。納米粉體經(jīng)200,350,500°C熱處理后,觀察其XRD圖譜變化及對其衍射峰參數(shù)的分析發(fā)現(xiàn),AgNPs及其復(fù)合NPs的尺寸均增大,結(jié)晶度均提高,且(Ag/Ag~+/Ag~(3+))NPs中Ag~+和Ag~(3+)的存在形態(tài)均遭到破壞;借助ESEM觀察發(fā)現(xiàn),納米粉體存在形貌發(fā)生改變;通過SEM觀測發(fā)現(xiàn),隨著溫度的升高納米粒子開始聚集,AgNPs的平均粒徑由15 nm左右增大至100 nm左右,(Ag/Ag~+/Ag~(3+))NPs的平均粒徑由20 nm左右增大至130 nm左右。500°C熱處理后,AgNPs及其復(fù)合NPs的抑菌性能均明顯減弱,處理前的抑菌能力基本是處理后的2~3倍;熱處理后,AgNPs對E.coli或S.aureus的MIC增大至2.31×10~(-4) mol/L左右,(Ag/Ag~+/Ag~(3+))NPs的MIC值增大至5.80×10~(-5)mol/L左右。所以,溫度會影響或改變納米粒子的存在形態(tài)、尺寸、結(jié)晶度和抑菌性能。對比AgNPs及(Ag/Ag~+/Ag~(3+))NPs熱處理前后的FTIR吸收峰發(fā)現(xiàn),多酚類,黃酮類,蛋白質(zhì)等大分子物質(zhì)相應(yīng)的吸收峰均消失,說明這些大物質(zhì)分子覆蓋在納米粒子表面,且被高溫分解。(4)通過對納米粒子的形成機理及抑菌機理的探索發(fā)現(xiàn),AgNPs及(Ag/Ag~+/Ag~(3+))NPs合成過程中遵循生物大分子與Ag~+發(fā)生吸附、還原和絡(luò)合的過程;其抑菌機理具有與菌體細胞多位點結(jié)合的特點;該機理為植物法合成AgNPs及復(fù)合NPs提供新思路和理論基礎(chǔ)。
[Abstract]:Silver nanoparticles (AgNPs) excellent conductive properties and composite nano particles have good antibacterial property, small size effect and quantum size effect, which is widely used in medical, electronic, food and other industries.AgNPs preparation methods mainly include physical method, chemical method and biological method and physical method and compared. Chemical method, biological method is efficient, fast, simple, environmentally friendly and low price and many other advantages. At present, people pay more attention to microbial research more, but plant method is seldom reported, in order to open up a new AgNPs and NPs composite plant preparation method, this study selected Green Tea, Ginkgo biloba, apple pomace as follows pomegranate peel extract as the reducing agent and stabilizer synthesis of AgNPs composite NPs. and its main contents and results: (1) Green Tea, Ginkgo biloba extract, apple pomace, and AgNO_3 mixed solution of pomegranate and other water plants, the preparation of AgNPs (or Ag/Ag~+ /Ag~ (3+) NPs); with the help of UV-vis, the nanoparticles were characterized by XRD and TEM instruments, detection and analysis of plant extracts macromolecules changes before and after the synthesis of nanoparticles using FTIR liquid containing plant; synthesis of AgNPs and its composite suitable conditions were determined by single factor experiments. The results showed that: Green Tea extracts the raw material, the synthesis conditions were: liquid ratio (g/mL), AgNO_3 1:30 concentration was 10 mmol/L, the volume of reaction liquid ratio of 1:5 (mL/mL), the average size of the AgNPs was 13.6 nm; apple pomace extract as raw material, the synthesis conditions were: liquid ratio (g/mL), AgNO_3 1:20 concentration was 15 mmol/L the reaction volume, liquid ratio 1:4 (mL/mL), the average size is 16 nm AgNPs; and the two plant extracts synthesized AgNPs high degree of crystallinity, morphology, spherical or nearly spherical, uniform size, particle dispersion. Ginkgo biloba extract as raw material, synthesis conditions As the ratio of material to liquid, the concentration of AgNO_3 (g/mL) 1:50 is 5 mmol/L, the volume of reaction liquid ratio of 1:8 (mL/mL), the preparation of (Ag/Ag~+/Ag~ (3+) NPs) dispersed high degree of crystallinity, spherical or nearly spherical, the average size of AgNPs is 13.8 nm, the average size of 24.6 AgONPs nm; to extract of pomegranate peel as raw material, obtained (Ag/Ag~+/Ag~ (3+) NPs), the synthesis conditions are: solution pH=8, AgNO_3 concentration was 10 mmol/L, the ratio of liquid to 1:15 (g/mL), compound NPs obtained more dispersed, good crystallinity and size distribution in 18~35 nm; FTIR analysis showed that polyphenols class, plant extracts, flavonoids, vitamin, protein and other substances in the formation of nanoparticles process reduction and protection. (2) using Vc as contrast, plant water extract on OH determination of scavenging O_2~- and DPPH free radicals, determine the antioxidative activity of strength; Determination of synthesis under the condition of Ag~+ The reduction rate of income; stability of AgNPs in solution were determined. The results showed that the extraction of antioxidant Green Tea liquid is stronger than Vc, has a strong ability to scavenge free radicals, the other 3 kinds of plant extracts. Green Tea; plant extracts of 4 kinds of free radical scavenging rate of the experimental results show that, the best of DPPH free radical scavenging effect of 4 kinds of plant extracts of Ginkgo biloba leaves were selected; through the determination of available Ag~+ reduction rate or conversion rate can reach above 99%; the synthesis of AgNPs was stable in solution. (3) using the inhibition zone method and MIC value test of the synthesis of AgNPs and (Ag/Ag~+/Ag~ (3+)) the results showed that the antibacterial properties of NPs, E.coli and S.aureus, AgNPs had better inhibitory ability against gram positive and gram negative bacteria growth, and (Ag/Ag~+/Ag~ (3+)) antibacterial ability of NPs is about 2~3 times of AgNPs; or AgNPs (Ag/Ag~+/Ag~ (3+) NPs) on E.coli and S. The aureus MIC value is about 1.15 * 10~ (-4) or mol/L is about 2.90 * 10~ (-5) mol/L. nano powder by 200350500 DEG C after heat treatment, observe the change of the spectrum and XRD analysis of the diffraction peak parameters, AgNPs and composite NPs size increased, the crystallinity increased, and the (Ag /Ag~+/Ag~ (3+) Ag~+) and Ag~ NPs (3+) forms were destroyed; with the aid of the ESEM observation found that the nano powder has the morphology changes; through SEM observation found that with the increase of temperature of the nanoparticles began to gather, the average particle size of the AgNPs increased from about 15 nm to about 100 nm, (Ag/Ag~+/Ag~ (3+)) NPs average particle size of from about 20 nm increased to 130 nm about.500 DEG C after heat treatment, and the antibacterial properties of AgNPs composite NPs significantly decreased, antibacterial ability before treatment is basically 2~3 times after treatment; after heat treatment, the AgNPs of E.coli or S.aureus increased to 2.31 MIC * 10~ (-4) M About ol/L (Ag/Ag~+/Ag~ (3+) NPs) MIC value increased to 5.80 * 10~ (-5) mol/L. So, the temperature will affect or change the existing form, particle size, crystallinity and antibacterial properties. Comparison of AgNPs and (Ag/Ag~+/Ag~ (3+) NPs) before and after heat treatment of the absorption peak of FTIR found that polyphenols class, flavonoids, proteins and other macromolecules corresponding to the absorption peak disappeared, indicating that these large molecules covered on the surface of nanoparticles, and is decomposed at high temperature. (4) by exploring the formation mechanism and the antibacterial mechanism of the nanoparticles, and AgNPs (Ag/Ag~+/Ag~ (3+)) NPs synthesis followed in the process of biological macromolecules with the occurrence of Ag~+ adsorption, reduction and complexation; its antibacterial mechanism has the characteristics of cell and multilocus combined; the mechanism to provide new ideas and theoretical basis for plant synthesis of AgNPs and NPs composite.

【學(xué)位授予單位】：陜西科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：O614.122;TB383.1

【參考文獻】

相關(guān)期刊論文 前10條

1 吳小煈;劉琳琳;解增旗;馬於光;;金屬納米粒子增強有機光電器件性能研究進展[J];高等學(xué)校化學(xué)學(xué)報;2016年03期

2 魏秀珍;姜興華;高美珍;;綠茶的保健作用研究[J];科技展望;2015年12期

3 田小溪;王伯良;曹義戰(zhàn);仲月霞;涂艷陽;校建波;何乾峰;翟麗娜;;Comparison of Protective Effects of Safflor Injection and Extract of Ginkgo Biloba on Lung Ischemia/Reperfusion Injury in Rabbits[J];Chinese Journal of Integrative Medicine;2015年03期

4 YAO Xin;CHEN Nan;MA Chun-Hua;TAO Jing;BAO Jian-An;CHENG Zong-Qi;CHEN Zu-Tao;MIAO Li-Yan;;Ginkgo biloba extracts attenuate lipopolysaccharide-induced inflammatory responses in acute lung injury by inhibiting the COX-2 and NF-κB pathways[J];Chinese Journal of Natural Medicines;2015年01期

5 曹雪玲;劉發(fā)現(xiàn);金麗;;納米銀膠的制備及對草莓的保鮮性能研究[J];食品工業(yè)科技;2014年05期

6 Ponarulselvam S;Panneerselvam C;Murugan K;Aarthi N;Kalimuthu K;Thangamani S;;Synthesis of silver nanoparticles using leaves of Catharanthus roseus Linn.G.Don and their antiplasmodial activities[J];Asian Pacific Journal of Tropical Biomedicine;2012年07期

7 許鳳鳳;魏取福;孟靈靈;;非織造基磁控濺射納米銀薄膜導(dǎo)電性能的研究[J];化工新型材料;2012年06期

8 劉艷娟;;催化光度法測定水中痕量銀[J];化學(xué)工程師;2010年11期

9 韓慧芳;楊丙雨;馮玉懷;李簡;;2001—2006年國內(nèi)光度法測定銀的概況[J];黃金;2008年10期

10 鮑云霞;;綠茶的化學(xué)成分與品質(zhì)[J];監(jiān)督與選擇;2007年06期

，

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