廖光福，張力，曾維國，張淑來，張博曉，喻春函，徐祖順

(有機功能分子合成與應(yīng)用教育部重點實驗室(湖北大學(xué))，有機化工新材料湖北省協(xié)同創(chuàng)新中心(湖北大學(xué))，湖北 武漢430062)

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磺化聚苯乙烯/聚苯胺/納米銀復(fù)合微球的制備及其催化性能研究

廖光福，張力，曾維國，張淑來，張博曉，喻春函，徐祖順

(有機功能分子合成與應(yīng)用教育部重點實驗室(湖北大學(xué))，有機化工新材料湖北省協(xié)同創(chuàng)新中心(湖北大學(xué))，湖北 武漢430062)

聚苯乙烯；磺化聚苯乙烯；聚苯胺；納米銀；復(fù)合微球；催化性能

0 引言

近年來，納米結(jié)構(gòu)材料因其化學(xué)、物理、生物特性以及在許多領(lǐng)域中的潛在應(yīng)用而引起人們的廣泛關(guān)注[1-2]. 特別是金屬納米粒子以及對應(yīng)的金屬氧化物，如Ag[3]、Au[4]、Cu[5]、TiO2[6]、ZnO[7]等，它們在催化劑領(lǐng)域已經(jīng)得到了廣泛的應(yīng)用. 其中，Ag作為一種催化效率非常高的催化材料[8-10]，在污水處理、光催化降解和光催化制氫等方面都有非常重要的應(yīng)用[11]. 然而，單一的納米銀作為催化材料具有易被氧化、易團聚和高成本等一系列缺點. 為了解決這些問題，科研人員已經(jīng)嘗試了很多方法，其中最重要的方法就是摻Ag至各種基材表面[12-15].選用聚合物微球作為基材，形成聚合物-納米銀核殼結(jié)構(gòu)復(fù)合微球可以很好的解決這些問題.

聚合物-金屬核殼結(jié)構(gòu)復(fù)合微球是由2種或2種以上的物質(zhì)(包括聚合物和金屬納米粒子)分別形成內(nèi)核和外殼，通過物理或者化學(xué)作用相互連接形成的復(fù)合材料[16]. 其中，殼層粒子不僅可以調(diào)整表面性質(zhì)，改變表面電荷密度、生物相容性、穩(wěn)定性及其分散性，而且還可以通過特殊梯度結(jié)構(gòu)將外殼粒子特有的電學(xué)性能、光學(xué)性能和催化活性等特性賦予整個微球[17]; 內(nèi)核微?？梢宰鳛槟０?，使外殼金屬納米粒子吸附或者接枝在其表面，從而提高復(fù)合微球的穩(wěn)定性和單分散性[18]. 因此，聚合物-金屬復(fù)合微球集有機、無機納米粒子等諸多性質(zhì)于一體，能夠?qū)崿F(xiàn)電學(xué)、光學(xué)、磁學(xué)以及催化等綜合性能的調(diào)控，在生物醫(yī)藥、組裝材料和催化領(lǐng)域具有廣闊的應(yīng)用前景[19-20].

本文中選用SPS/PANI復(fù)合微球作為基材，在此基材表面沉積納米銀，制備了一種新型的SPS/PANI/Ag復(fù)合微球. 選用SPS/PANI復(fù)合微球作為基材不僅可以很好的解決納米銀面臨的這些問題，而且SPS/PANI復(fù)合微球與納米銀具有很大的接觸面積，可以有效的提高納米銀的催化效率. 我們首先用分散聚合制備了PS微球；然后用濃硫酸對PS微球進行磺化形成了SPS微球；隨后以SPS微球為模板，并在其表面發(fā)生苯胺的氧化聚合形成SPS/PANI復(fù)合；最后，Ag納米粒子被沉積到SPS/PANI微球表面形成SPS/PANI/Ag復(fù)合微球. 我們通過SPS/PANI/Ag復(fù)合微球催化NaBH4還原MB的模型來研究其催化性能. 結(jié)果表明，SPS/PANI/Ag復(fù)合微球在NaBH4還原MB的模型中表現(xiàn)出較高的催化活性和較高的重復(fù)利用率.

1 實驗部分

1.1 實驗試劑 苯乙烯(St)，苯胺(An) ,分析純，上海阿拉丁生化科技股份有限公司，減壓蒸餾后使用；偶氮二異丁腈(AIBN)、聚乙烯吡咯烷酮(PVP)、無水乙醇、硝酸銀(AgNO3)、濃硫酸(H2SO4)、濃鹽酸(HCl)、濃氨水(NH3·H2O)、過硫酸銨(APS)，分析純，國藥集團化學(xué)試劑有限公司.

1.2 實驗方法

1.2.1 單分散PS微球的制備 采用分散聚合制備單分散PS微球. 15 g St、3 g PVP、0.2 g AIBN、95 g 無水乙醇和5 g 去離子水加入到250 mL 四口瓶中，通氮氣保護，在70 ℃恒溫水浴中反應(yīng)24 h. 停止加熱，離心并抽濾，用去離子水和無水乙醇洗滌多次，真空干燥得到PS微球.

1.2.2 SPS微球的制備 將3.4 g PS粉末和120 mL 濃硫酸分散于250 mL 三口瓶中，超聲30 min. 隨后，在40 ℃恒溫水浴中反應(yīng)12 h. 停止加熱，離心并抽濾，用去離子水和無水乙醇洗滌多次，真空干燥得到SPS微球.

1.2.3 SPS/PANI復(fù)合微球的制備 將0.3 g SPS 粉末、0.05 g An、40 mL 去離子水和2 mL HCl(2 mol/L)混合均勻，超聲30 min. 隨后，將混合物至于冰浴中攪拌5 h，然后緩慢滴加0.12 g APS(溶解于2 mL去離子水中)，滴加完畢后在冰浴下反應(yīng)24 h. 停止加熱，離心并抽濾，用去離子水和無水乙醇洗滌多次，真空干燥得到SPS/PANI復(fù)合微球.

圖1 SPS/PANI/Ag復(fù)合微球的制備過

1.2.4 SPS/PANI/Ag復(fù)合微球的制備 將0.13 g SPS/PANI粉末、1 g PVP 和50 mL 去離子水混合均勻，超聲30 min. 隨后，10 mL 現(xiàn)配的銀氨溶液(0.2 mol/L)迅速加入以上混合物中，在室溫下攪拌1h. 最后，在70 ℃和通氮氣條件下反應(yīng)7 h. 停止加熱，離心并抽濾，用去離子水和無水乙醇洗滌多次，真空干燥得到SPS/PANI/Ag復(fù)合微球. 制備過程如圖1所示.

2 結(jié)果與討論

2.2 XRD分析 圖3為SPS/PANI/Ag復(fù)合微球的XRD譜圖. 對照PDF卡片可以看出，在2θ值約為38.0°、44.1°、64.3°、77.2°和 81.5°出現(xiàn)尖銳峰，與純銀納米粒子衍射峰完全一致，反映了銀納米粒子面心立方結(jié)構(gòu)(111)、(200)、(220)、(311)和(222)的5個晶面[21]，這說明SPS/PANI/Ag復(fù)合微球中的Ag納米粒子為結(jié)晶態(tài). 樣品的衍射峰較尖銳，說明復(fù)合微球中生成的銀納米粒子的晶型較好.

圖2 PS微球、SPS微球、SPS/PANI復(fù)合微球和SPS/PANI/Ag復(fù)合微球的紅外圖

圖3 SPS/PANI/Ag復(fù)合微球的XRD圖譜

圖4 PS微球(a)、SPS微球(b)、SPS/PANI復(fù)合微球(c)、SPS/PANI/Ag復(fù)合微球(d)的FESEM圖和PS微球(e)、SPS微球(f)、SPS/PANI復(fù)合微球(g)、SPS/PANI/Ag復(fù)合微球(h)的EDX譜圖

圖5 3 mL MB(10 mg/mL)溶液和0.5 mLNaBH4 (10 mg/mL)的混合液在不同時間的紫外圖譜(插 圖顯示相應(yīng)的MB溶液的顏色)

圖6 1 mL SPS/PANI/Ag(0.03 mg/mL)溶液加至3 mL MB(10 mg/mL)溶液和0.5 mL NaBH4(10 mg/mL)的混合液中在不同時間的紫外圖譜(插圖顯示相應(yīng)的MB溶液的顏色)

圖7 SPS/PANI/Ag催化材料的回收利用圖

3 結(jié)論

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(責(zé)任編輯 胡小洋)

Preparation and catalytic properties of sulfonated polystyrene/polyaniline/silver composite microspheres

LIAO Guangfu, ZHANG Li, ZENG Weiguo, ZHANG Shulai, ZHANG Boxiao, YU Chunhan, XU Zushun

(Ministry of Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules(Hubei University),Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials(Hubei University), Wuhan 430062,China)

In this work, new sulfonated polystryrene/polyaniline/silver(SPS/PANI/Ag) composite microspheres were prepared by using multifunctional sulfonated polystryrene/polyaniline(SPS/PANI) composite microspheres as substrates and utilizing polyvinylpyrrolidone(PVP) as reducing agent and stabilizing agent. The morphology, compenent, structure and catalytic properties of the composite microspheres were characterized and investigated by Fourier transform infrared spectrum(FT IR), field emission scanning electron microscopy(FESEM), energy disperse spectroscopy(EDX), Powder X-ray diffraction(XRD) and UV-visible spectroscopic techniques(UV). The results confirmed the formation of PS microspheres, SPS microspheres, SPS/PANI composite microspheres, and SPS/PANI/Ag composite microspheres. Ag nanoparticles and PANI was uniformly distributed on the surface of SPS microspheres with its size ranging from 1.2 to 1.3 μm. And the SPS/PANI/Ag composite microspheres shown high catalytic activity and high recycling rate in the model with methylene blue(MB) dye was reduced by sodium hydride(NaBH4).

polystyrene;sulfonated polystyrene;polyaniline;silver nanoparticles;composite microspheres;catalytic property

2016-08-24

武漢市高新技術(shù)成果轉(zhuǎn)讓及專業(yè)化項目(2014010303010159)資助

廖光福(1992-)，男，碩士生；徐祖順，通信作者，教授，E-mail：zushunxu@hubu.edu.cn

1000-2375(2017)04-0400-05

O643.3

A

10.3969/j.issn.1000-2375.2017.04.012