呂生華，朱琳琳，李 瑩，賀亞亞，楊文強(qiáng)

(陜西科技大學(xué) 資源與環(huán)境學(xué)院，西安 710021)

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氧化石墨烯復(fù)合材料的研究現(xiàn)狀及進(jìn)展

呂生華，朱琳琳，李 瑩，賀亞亞，楊文強(qiáng)

(陜西科技大學(xué) 資源與環(huán)境學(xué)院，西安 710021)

氧化石墨烯(Graphene Oxide，GO)以其獨(dú)特的二維納米片層結(jié)構(gòu)、超大的比表面積和親水極性界面，使其在功能復(fù)合材料領(lǐng)域有著廣泛的應(yīng)用和發(fā)展前景。本文綜述了近年來(lái)GO復(fù)合材料在增強(qiáng)增韌、吸附分離、光催化及生物醫(yī)藥等方面的研究現(xiàn)狀及進(jìn)展，介紹了GO調(diào)控高分子材料及水泥基體形成規(guī)整有序的微觀結(jié)構(gòu)形貌而產(chǎn)生顯著的增強(qiáng)增韌效果的機(jī)理，分析了GO復(fù)合材料在吸附、催化、生物醫(yī)藥等方面作用原理，指出了GO增強(qiáng)增韌復(fù)合材料、GO吸附復(fù)合材料和GO光催化復(fù)合材料的應(yīng)用前景和發(fā)展趨勢(shì)。

氧化石墨烯；復(fù)合材料；微觀結(jié)構(gòu)；增強(qiáng)增韌；光催化降解

氧化石墨烯(Graphene Oxide，GO)是將石墨氧化后經(jīng)過(guò)超聲剝離、分散、粉碎后得到的片層狀物質(zhì)，從化學(xué)結(jié)構(gòu)上看GO是石墨烯的氧化產(chǎn)物，與石墨烯相同的是其結(jié)構(gòu)單元具有由C原子構(gòu)成六元環(huán)狀結(jié)構(gòu)，與石墨烯不同的片層結(jié)構(gòu)上帶有親水性基團(tuán)，如羧基、羥基和環(huán)氧基等，在水相中容易分散成為穩(wěn)定的納米片層分散液，GO分散液中的聚集態(tài)GO是由不同片層數(shù)構(gòu)成，其片層的數(shù)量與GO的制備過(guò)程及分散條件有關(guān)系，對(duì)GO的應(yīng)用有重要的影響。目前，GO的用途主要有：(1)制備還原氧化石墨烯(Reduction of Graphene Oxide, RGO)。通過(guò)GO與還原性的化學(xué)試劑如水合肼、苯肼、抗壞血酸、沒(méi)食子酸、硼氫化鈉等[1-11]反應(yīng)制備RGO，將RGO廣泛應(yīng)用于電池的電極材料、超級(jí)電容器、生物傳感器、催化劑組分等領(lǐng)域；(2)制備吸附材料。GO具有很好的吸附性能，通過(guò)與一些化學(xué)材料的復(fù)合及化學(xué)改性[12-17]等反應(yīng)，在GO上接枝特定吸附功能化學(xué)基團(tuán)，提高吸附的選擇性和效果；(3)制備復(fù)合材料。GO與有機(jī)物和無(wú)機(jī)物通過(guò)原位聚合、物理共混等方法制備復(fù)合材料，顯著提高材料的強(qiáng)度和韌性等性能[18,19]。由于GO的納米片層結(jié)構(gòu)狀態(tài)，直接使用GO受到了很大的限制，目前GO的主要用途是制備復(fù)合材料，其中增強(qiáng)增韌復(fù)合材料、吸附復(fù)合材料及其具有催化、蛋白修復(fù)等功能的復(fù)合材料成為了研究的熱點(diǎn)。本文主要綜述了采用GO制備增強(qiáng)增韌、吸附、光催化降解等功能復(fù)合材料的研究進(jìn)展，展望了GO在復(fù)合材料中的應(yīng)用前景。

1 GO/聚合物復(fù)合材料研究進(jìn)展

1.1 GO/聚L-乳酸(PLLA)基復(fù)合材料

GO具有納米片層結(jié)構(gòu)，其尺寸大小可以調(diào)控，而且片層上帶有羧基、羥基等化學(xué)基團(tuán)，在能夠形成晶體的環(huán)境中，GO的參與可以調(diào)控和改變晶體的形狀和聚集方式，從而提高材料的熱穩(wěn)定性和力學(xué)性能。研究表明，L-聚乳酸(Poly(L-Lactic Acid), PLLA)存在力學(xué)性能差、結(jié)晶速率低、降解速率慢以及生物相容性差的問(wèn)題[20-23]。GO納米片層能夠調(diào)控聚PLLA的結(jié)晶行為，使其形成規(guī)整有序、分布均勻的花瓣?duì)罹w(圖1)，顯著提高PLLA耐熱性能和力學(xué)性能[20]。

1.2 GO/聚ε-己內(nèi)酯(PCL)基復(fù)合材料

RGO是GO在還原劑的作用下得到的，是含氧量較低的GO。Wang等[25]研究了RGO和GO對(duì)聚ε-己內(nèi)酯(Poly(e-Caprolactone), PCL)微觀結(jié)構(gòu)及性能的影響，結(jié)果表明，摻有RGO和GO的聚合物的微觀結(jié)構(gòu)中均出現(xiàn)了規(guī)整的晶體(圖2)，其屈服應(yīng)力和楊氏模量都有約24%的提升，GO比RGO 的增強(qiáng)增韌效果更加明顯。

圖1 純PLLA(a),PLLA/0.5%GO(b),PLLA/1%GO(c)和PLLA/2%GO(d)在138℃的POM圖[20]Fig.1 POM images of neat PLLA(a)， PLLA/0.5%GO(b),PLLA/1%GO(c) and PLLA/2%GO(d) crystallized at 138℃[20]

1.3 GO/玻璃纖維基復(fù)合材料

Ning等[26]討論了玻璃纖維、氨基改性玻璃纖維和用GO改性玻璃纖維的微觀結(jié)構(gòu)和性能，結(jié)果表明，GO的引入使得玻璃纖維的半晶態(tài)聚合物在界面處的結(jié)晶性能明顯提升，同時(shí)材料的力學(xué)性能也獲得了較大的提升。因此，GO可以用于玻璃纖維基復(fù)合材料的增強(qiáng)和增韌。

1.4 水泥/GO復(fù)合材料

GO納米片層對(duì)于水泥水化產(chǎn)物的形狀及聚集態(tài)結(jié)構(gòu)和性能有顯著的調(diào)控作用。呂生華等[27]研究了GO納米片層摻入量為水泥質(zhì)量的0%～0.06%時(shí)，水泥基復(fù)合材料的微觀結(jié)構(gòu)和力學(xué)性能變化(表1)，結(jié)果表明，添加GO后水泥試樣的力學(xué)性能有了顯著的提高。

摻有GO的水泥基體SEM形貌如圖3所示[27]。結(jié)果表明，沒(méi)有摻入GO的水泥基體雖然有棒狀和片狀晶體，但是其聚集方法呈現(xiàn)雜亂無(wú)章的堆疊，存在著大量的縫隙和孔洞。摻入GO的水泥基體中形成了由棒狀、花狀和多面體狀晶體構(gòu)成的規(guī)整有序的聚集狀態(tài)，同時(shí)發(fā)現(xiàn)晶體在結(jié)構(gòu)疏松的部位以及孔隙、孔洞部位較多，其生長(zhǎng)過(guò)程對(duì)于這些結(jié)構(gòu)缺陷進(jìn)行了修復(fù)，使得水泥基復(fù)合材料的結(jié)構(gòu)均勻和緊實(shí)，從而提高了水泥基材料的力學(xué)性能。

圖2 不同結(jié)晶時(shí)間時(shí)純PCL(1)和PCL/0.1%RGO納米復(fù)合物(2)的POM圖[25] (a)1min;(b)4min;(c)7minFig.2 POM images of neat PCL(1) and PCL/0.1%RGO nanocomposites(2) in different crystallization time[25] (a)1min;(b)4min;(c)7min

MassofGO/gCompressivestrength/MPaRateofincrease/%Flexuralstrength/MPaRateofincrease/%Tensilestrength/MPaRateofincrease/%0.0036.74/59.310.0/0.05.63/8.840.0/0.01.94/3.830.0/0.00.0141.23/67.2412.2/13.48.55/13.4151.9/51.72..47/5.6328.0/47.00.0248.33/75.6631.5/27.68.68/11.7554.2/32.92.48/6.1128.6/59.50.0353.32/82.3645.1/38.99.11/14.2161.8/60.72.93/6.3451.0/65.50.0456.42/84.3553.6/42.28.13/13.5444.4/53.22.72/5.8340.2/52.20.0558.45/87.6959.0/47.97.21/11.5128.1/30.22.41/5.2024.2/35.8

呂生華等[28,29]研究了GO 片層含氧量對(duì)水泥水化產(chǎn)物的結(jié)晶形狀和性能的影響，結(jié)果表明，隨著含氧量的增加，水泥基體中形成的規(guī)則晶體的數(shù)量增多，而力學(xué)性能也呈現(xiàn)增加的趨勢(shì)(圖4)。GO片層含氧量為9.31%時(shí)，形成規(guī)整的花狀結(jié)構(gòu)，體積較小，數(shù)量較少，分布不均勻，力學(xué)性能提高率在20%左右；含氧量在25.43%時(shí)，花狀晶體體積變大，數(shù)量增多，分布均勻，力學(xué)性能提高率達(dá)30%；含氧量為31.78%時(shí)，形成多面體結(jié)構(gòu)，體積大，數(shù)量多，抗壓強(qiáng)度高。

圖4 不同GO含氧量的水泥水化產(chǎn)物養(yǎng)護(hù)28d的SEM圖[29] (a)9.31%；(b)25.43%；(c)31.78%Fig.4 SEM images of cement hydration products at 28d with GO of different oxygen content added 9.31%(a),25.43%(b) and 31.78%(c) [29]

呂生華等[28,29]通過(guò)觀察GO摻量為0.03%時(shí)不同養(yǎng)護(hù)時(shí)間水泥水化基體的SEM形貌(圖5)，分析了其生長(zhǎng)的過(guò)程，結(jié)果表明，養(yǎng)護(hù)1天后較多的微球狀晶體生長(zhǎng)出來(lái)，養(yǎng)護(hù)3天后長(zhǎng)成棒狀的晶體，養(yǎng)護(hù)7天后長(zhǎng)出了由棒狀晶體組裝形成的花形晶體，養(yǎng)護(hù)28天后長(zhǎng)成大體積的花狀晶體，養(yǎng)護(hù)60天時(shí)花狀晶體形成了密集的簇狀晶體，90天時(shí)花狀晶體通過(guò)相互貫穿、交叉構(gòu)成較為密實(shí)的交聯(lián)狀結(jié)構(gòu)。這些水化晶體的生長(zhǎng)形成了交聯(lián)、密集的微觀結(jié)構(gòu)，提高了水泥基材料的體積穩(wěn)定性和力學(xué)性能。

圖5 GO摻量0.03%時(shí)在不同水化時(shí)間的水泥水化晶體的SEM圖[30] (a)1天;(b)3天;(c)7天;(d)28天;(e)60天;(f)90天Fig.5 SEM images of cement hydration crystals with 0.03%GO with different hydration time[30](a)1d;(b)3d;(c)7d;(d)28d;(e)60d;(f)90d

在上述分析的基礎(chǔ)上，Lv等[30]提出GO調(diào)控水泥水化結(jié)晶的作用機(jī)理(圖6)。首先，水泥基中的活性成分與GO上的活性基團(tuán)作用，形成晶體的生長(zhǎng)點(diǎn)，吸引水泥基材料的活性成分繼續(xù)反應(yīng)形成棒狀晶體，聚集在一起的棒狀晶體在水泥基體中的孔洞、裂縫處分裂形成花狀晶體。GO納米片層在水泥水化晶體的形成過(guò)程中起著模板和組裝的作用。

圖6 GO 對(duì)水泥水化產(chǎn)物的調(diào)控機(jī)理圖(a)和SEM圖(b)[30]Fig.6 Schematic(a) and SEM image(b) of the regulatory mechanism of GO on cement hydration products[30]

Fakhim課題組[31]摻入了0.1%～2.0%的GO，制備得到GO-cement復(fù)合材料。發(fā)現(xiàn)在GO摻量為水泥量的1.5%時(shí)，水泥基材料的拉伸強(qiáng)度提高了48%。通過(guò)SEM檢測(cè)，發(fā)現(xiàn)在水泥基體中有針狀晶體聚集區(qū)和片層狀晶體聚集區(qū)，晶體聚集區(qū)的存在說(shuō)明GO對(duì)水泥水化產(chǎn)物形狀有調(diào)控作用，也表明GO在水泥基體中分布不均勻。通過(guò)一定的手段使得GO納米片層均勻地分散在水泥基體中，其微觀結(jié)構(gòu)也呈現(xiàn)了規(guī)整有序、均勻的微觀結(jié)構(gòu)，力學(xué)性能提高了很多，說(shuō)明了GO納米片層的分散是關(guān)鍵因素。

2 GO復(fù)合吸附材料研究進(jìn)展

GO片層具有超大比表面積，表面上含有羧基、羥基、環(huán)氧基等基團(tuán)[32]，使得GO具有特別優(yōu)異的吸附性能，GO在吸附材料中有著重要的應(yīng)用[33-36]。

2.1 GO磁性復(fù)合吸附材料研究進(jìn)展

復(fù)合材料的磁性主要是引入了磁性Fe3O4粒子，利用磁性使其再生時(shí)方便回收吸附，提高吸附材料的循環(huán)使用的次數(shù)。張燚等[37]采用高溫分解法制備得到了粒徑18nm左右的Fe3O4納米粒子，經(jīng)過(guò)復(fù)雜的表面修飾后與GO得到磁性復(fù)合材料，飽和磁場(chǎng)強(qiáng)度達(dá)41.3A·m2·kg-1。Fan等[38]制備了結(jié)構(gòu)穩(wěn)定、可重復(fù)使用的磁性殼聚糖/GO復(fù)合材料，具有再生方便快捷的特點(diǎn)，對(duì)于Pb(Ⅱ)的吸附能力可達(dá)76.94mg·g-1，解吸效率達(dá)90.3%。Fan等[39]研究了Fe3O4-β環(huán)糊精-殼聚糖/GO納米吸附材料對(duì)染料的吸附，初次的吸附能力為50mg·g-1，經(jīng)過(guò)5次的吸附循環(huán)過(guò)程后，對(duì)廢水中甲基藍(lán)的吸附量能夠保持在30mg·g-1。Ye等[40]制備得到Fe3O4/GO/殼聚糖復(fù)合材料，將其應(yīng)用于對(duì)蛋白質(zhì)的富集吸附，吸附量達(dá)到了7.57mg·g-1。Ehsan等[41]用3-巰基丙烷對(duì)GO-磁性殼聚糖(GO-MC)復(fù)合材料進(jìn)行了改性，制備得到一種新型的生物吸附劑，可用于污水中Hg2+的預(yù)富集和萃取。饒維等[42]對(duì)環(huán)境中含量低、危害大的四溴雙酚A的吸附處理進(jìn)行了研究，制備出了對(duì)四溴雙酚A(Tetrabromobisphenol A, TBBPA)，具有高選擇性和高吸附容量的磁性印跡復(fù)合材料，對(duì)TBBPA材料的飽和吸附量為16.33mg·g-1，并且TBBPA回收效率達(dá)86.30%～98.60%，而沒(méi)有加入TBBPA的磁性復(fù)合材料的飽和吸附量?jī)H為0.87mg·g-1。研究表明，ZnO具有化學(xué)惰性[43]，在光催化降解有機(jī)污染物時(shí)扮演著非常重要的角色，然而ZnO只能吸收紫外區(qū)域的光進(jìn)行催化降解，若在ZnO上摻雜Ni[44]、強(qiáng)吸附性能的GO[45]就可以明顯提高其降解性能。Qin等[46]制備了Ag/ZnO/GO復(fù)合材料，可使催化降解后羅丹明B的去除效率達(dá)90%。

2.2 GO非磁性復(fù)合吸附材料研究進(jìn)展

非磁性GO基復(fù)合材料主要是處理水體中的重金屬污染和有機(jī)物污染，是磁性GO基復(fù)合材料的重要補(bǔ)充，同樣獲得了廣泛的研究。

殼聚糖分子鏈上含有較多的—NH2和其他活性基團(tuán)，使其具有獨(dú)特的理化性能和生物活化功能，因而廣泛應(yīng)用于吸附和絮凝領(lǐng)域。但是殼聚糖本身的力學(xué)性能很差，限制了其應(yīng)用。而GO具有很強(qiáng)的力學(xué)性能和反應(yīng)活性，許多研究人員將殼聚糖和GO復(fù)合后進(jìn)行了研究。GO/CS復(fù)合材料對(duì)不同污染物吸附性能如表2所示。

Luo等[54]發(fā)現(xiàn)，除了殼聚糖含有較多與重金屬離子作用的基團(tuán)外，聚氨基硅氧烷(Poly3-Aminopropyltriethoxysilane, PAS)上含有的大量—NH2，能夠同一些金屬離子如Pb(Ⅱ)形成穩(wěn)定的絡(luò)合物。GO具有大比表面積和豐富的含氧官能團(tuán)，在GO納米片層上交聯(lián)氨基硅氧烷低聚物(以3-氨丙基三乙氧基硅烷為交聯(lián)劑)制備高性能吸附劑，明顯提升了復(fù)合材料的吸附性能，在pH=4～6、溫度為303K時(shí)PAS/GO，GO/AS的最大吸附量分別為312.5，119.05mg·g-1，聚合物復(fù)合材料的吸附能力明顯高于PAS。復(fù)合材料的PAS/GO的制備流程如圖7所示。

表2 GO/CS復(fù)合材料對(duì)不同污染物最大吸附量

圖7 PAS/GO復(fù)合材料的制備流程[54]Fig.7 Schematic illustration of preparation for PAS/GO composites[54]

Xia等[55]將不同濃度的GO作為外加劑加入到聚偏二氟乙烯(Poly(Vinylidene Fluoride), PVDF)，采用相轉(zhuǎn)移催化法制備得到了PVDF-GO復(fù)合薄膜，應(yīng)用于天然有機(jī)物質(zhì)的吸附去除，吸附性能提高了1倍。GO的加入不僅提升了復(fù)合物薄膜的機(jī)械強(qiáng)度[56-58]，而且增強(qiáng)了材料的抗菌性能[59，60]和滲透性能，對(duì)污水處理能力也得到提升。

當(dāng)前吸附劑的發(fā)展方向是高選擇性、高吸附效率和高重復(fù)利用率，GO的摻入有助于提高吸附劑選擇性和吸附效率。

3 GO光催化降解復(fù)合材料研究進(jìn)展

光催化技術(shù)廣泛應(yīng)用于降解有機(jī)物[61-63]物質(zhì)，研究發(fā)現(xiàn)，光催化劑的催化能力不僅與其晶型、粒徑大小和結(jié)晶程度相關(guān)，而且往往會(huì)與某些材料復(fù)合產(chǎn)生協(xié)同作用，如與碳納米管、富勒烯、石墨烯、GO等進(jìn)行復(fù)合，可以提高光子在材料中的傳遞速率，增強(qiáng)復(fù)合材料對(duì)于廢水中的有機(jī)物和空氣中的有害氣體的光催化性能。

張瓊等[64]用Ti(SO4)2和經(jīng)不同濃度的NaOH處理的不同分散程度的GO分散液復(fù)合，經(jīng)過(guò)干燥得到一系列TiO2/GO復(fù)合材料，測(cè)其光催化降解性能時(shí)以濃度為20mg/L的甲基橙為目標(biāo)降解物，降解效率η=1.16mg/(min·g)。當(dāng)經(jīng)過(guò)多次循環(huán)降解過(guò)程和4周敞口存放，其光催化效率只發(fā)生稍微降低，表現(xiàn)出非常好的重復(fù)利用率和化學(xué)穩(wěn)定性，為TiO2/GO復(fù)合材料在催化降解廢水有機(jī)物和空氣中的有害氣體提供了更多的參考。Chen等[65]通過(guò)兩步法改性制備了ZnO/GO復(fù)合材料，與單獨(dú)使用ZnO和GO相比，復(fù)合材料光催化降解甲基橙的效率獲得了很大的提高。Qin等[46]將Ag納米顆粒和GO負(fù)載到ZnO上，應(yīng)用于降解羅丹明B，結(jié)果表明，復(fù)合材料將催化劑可用光源的范圍擴(kuò)充到可見(jiàn)-紫外光區(qū)，并取得很好的催化降解效果。對(duì)于羅丹明B的催化降解，Li等[66]采用原位聚合法制備了多組分復(fù)合材料GO-PA-CeOX，結(jié)果顯示，聚丙烯酰胺(Polyacryl Amide, PAM)和Ce的氧化物很好地負(fù)載在了GO的納米片層上，最后將復(fù)合材料和GO應(yīng)用于催化降解羅丹明B的實(shí)驗(yàn)，在相同的條件下進(jìn)行對(duì)比，經(jīng)過(guò)30min和70min的紫外光的照射，GO和復(fù)合材料對(duì)羅丹明B的降解效率分別為18%，31%和50%，80%，復(fù)合材料的催化降解性能明顯優(yōu)于GO。

綜上所述，GO光催化復(fù)合材料在光催化降解領(lǐng)域表現(xiàn)出非常優(yōu)異的性能，原因歸結(jié)為：(1)GO的引入在很大程度上增加了復(fù)合材料的比表面積，提高了復(fù)合材料與光子的接觸機(jī)會(huì)，增強(qiáng)了復(fù)合材料對(duì)有機(jī)污染物的吸附能力；(2)在復(fù)合材料界面形成的異質(zhì)結(jié)改善了光生電子和空穴的復(fù)合；(3)GO的引入在一定程度上提高了催化材料的吸收波長(zhǎng)的范圍，為在可見(jiàn)光范圍內(nèi)進(jìn)行光催化降解提供了可能。

4 GO生物醫(yī)學(xué)復(fù)合材料研究進(jìn)展

GO對(duì)于生物蛋白的富集吸附是一種非特異性吸附，會(huì)引起蛋白質(zhì)發(fā)生聚集、結(jié)構(gòu)異變和失掉蛋白活性[67，68]。而聚乙二醇(Polyethylene Glycol, PEG)是一種多羥基化合物，具有很好的生物相容性，對(duì)于細(xì)胞和生物蛋白吸附性能較弱。如果將聚乙二醇和GO進(jìn)行復(fù)合，可以很好地改善GO表面化學(xué)性質(zhì)，并且能夠形成和蛋白質(zhì)相互作用的納米表面，改善GO對(duì)蛋白質(zhì)結(jié)構(gòu)和活性的不利影響。Chen等[69]通過(guò)原位生長(zhǎng)和自組裝法，將FeOOH納米棒與經(jīng)過(guò)PEG接枝改性的GO進(jìn)行復(fù)合，制備了對(duì)生物全血白蛋白有高效吸附作用的FeOOH-PEG-GO復(fù)合材料，結(jié)果表明，該復(fù)合材料對(duì)牛血清白蛋白(沒(méi)有亞鐵血紅素)的最高吸附量達(dá)1377.4mg·g-1，在pH=12～13時(shí)的解析率為70%，很好地減弱了對(duì)非特異性蛋白的吸附。

DNA尿嘧啶糖基化酶(Uracil-DNA Glycosylase, UDG)是一種重要的剪切修復(fù)酶，有維護(hù)基因結(jié)構(gòu)完整性的作用。Zhou等[70]將示蹤熒光探針負(fù)載到GO片層上，制備了一種GO基生物探針，發(fā)現(xiàn)在較寬的動(dòng)態(tài)范圍(0.0017～0.8U/mL)有很好的檢測(cè)效果，而且最低檢出限為0.0008U/mL。Xin等[71]則采用靜電紡絲法制備了熱塑型的小直徑人工血管支架聚氨酯-GO復(fù)合材料，其力學(xué)性能、表面性能、拉伸性能、楊氏模量及親水性均滿足要求。在抑菌方面，Andreia等[59]以AgNO3為銀納米顆粒前驅(qū)物、檸檬酸鈉為穩(wěn)定劑，將銀納米顆粒裝飾到GO 片層上，制備了GO/Ag納米復(fù)合材料，應(yīng)用于抑制綠膿假單胞菌，經(jīng)過(guò)1h的抑菌實(shí)驗(yàn)，復(fù)合材料的抑菌效率在95%以上。Justin等[72]在藥物載體研究中采用便宜易得、易生物降解的殼聚糖和高機(jī)械強(qiáng)度、比表面積大和多活性官能團(tuán)的GO制備納米復(fù)合材料，在給藥設(shè)備中有潛在的應(yīng)用價(jià)值。Wang等[73]用魔芋葡甘聚糖(Konjac Glucomannan，KGM)、海藻酸鈉(Sodium Alginate, SA)和GO為原料，以Ca2+做交聯(lián)劑制備水凝膠KGM/SA/GO，使得抗癌藥物達(dá)到可控釋放，當(dāng)pH=1.2時(shí)藥物的平衡釋放率僅為38.02%，而pH=6.8時(shí)，經(jīng)過(guò)12h后平衡釋放率達(dá)84.19%。KGM/SA/GO凝膠過(guò)程如圖8所示。

GO基生物醫(yī)學(xué)復(fù)合材料在吸附特異性蛋白、藥物載體、基因工程及調(diào)控藥物的釋放等領(lǐng)域表現(xiàn)出優(yōu)異的性能，隨著研究的深入，相信GO基生物醫(yī)學(xué)復(fù)合材料最終將在抗癌領(lǐng)域有所突破。

5 結(jié)束語(yǔ)

目前，GO復(fù)合材料的應(yīng)用和研究已經(jīng)成為研究的熱點(diǎn)之一，原因是GO獨(dú)特的結(jié)構(gòu)和性能使其形成的復(fù)合材料在強(qiáng)度韌性、吸附分離和光催化等方面比起傳統(tǒng)的材料具有明顯的優(yōu)勢(shì)，滿足了一些領(lǐng)域技術(shù)發(fā)展對(duì)于材料性能的要求。同時(shí)，GO與其他材料形成復(fù)合材料是GO發(fā)揮作用的主要途徑，其中GO在復(fù)合材料中的作用又與GO的結(jié)構(gòu)和性能有很大的關(guān)系。比如，GO增強(qiáng)增韌高分子材料和水泥基材料，就是通過(guò)GO調(diào)控高分子和水泥基材料，從而形成了規(guī)整有序的微觀結(jié)構(gòu)而實(shí)現(xiàn)其增強(qiáng)增韌作用。今后，GO在增強(qiáng)增韌、吸附分離、光催化等功能復(fù)合材料的發(fā)展趨勢(shì)是：(1)GO復(fù)合材料的制備及GO在其中的作用原理是研究的重點(diǎn)；(2)GO增強(qiáng)增韌復(fù)合材料具有產(chǎn)業(yè)化、規(guī)?；瘧?yīng)用的可能，其中GO增強(qiáng)增韌高分子材料、GO增強(qiáng)增韌水泥基復(fù)合材料、GO增強(qiáng)增韌陶瓷材料等方面的技術(shù)已經(jīng)比較成熟，達(dá)到了產(chǎn)業(yè)化的要求；(3)GO復(fù)合材料在吸附、光催化和生物醫(yī)藥領(lǐng)域的研究還處于研究階段，有關(guān)GO復(fù)合材料的結(jié)構(gòu)和性能之間的關(guān)系還沒(méi)有建立，產(chǎn)業(yè)化關(guān)鍵技術(shù)還沒(méi)有掌握，GO復(fù)合材料的規(guī)?；?、高效率及可重復(fù)使用的技術(shù)問(wèn)題還沒(méi)有解決，這些方面的產(chǎn)業(yè)化應(yīng)用還需要做大量的研究工作。

圖8 KGM(a),SA(b)和KGM/SA/GO(c)凝膠過(guò)程[73]Fig.8 Gel process of KGM(a),SA(b),and KGM/SA/GO(c)[73]

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Current Situation and Progress of Graphene Oxide Composites

LYU Sheng-hua，ZHU Lin-lin，LI Ying，HE Ya-ya，YANG Wen-qiang

(College of Resources & Environment,Shaanxi University of Science &Technology,Xi’an 710021,China)

Graphene oxide (GO) has wide applications and development prospects in the functional composites owing to its many unique properties, such as two-dimensional structure and large theoretical specific surface areas as well as hydrophilic and polarized interface. The present situation and progress of the graphene oxide composites used in reinforcing and toughening, adsorption separation, photocatalysis and biological medicine were introduced in this paper. The mechanism of producing reinforcing and toughening of polymer and cement based composites caused by forming regular and ordered microstructure regulated with GO nanosheets was mainly summerized. Meanwhile, application principle of the GO composites in the field of adsorption, photocatalysis and biological medicine were analyzed. Finally, the application and development trend of GO composites in reinforcing and toughness as well as adsorption and photocatalysis were pointed out.

graphene oxide;composite material;microstructure；reinforcing and toughening;photocatalytic degradation

10.11868/j.issn.1001-4381.2016.12.017

O613.71；TQ172.4

A

1001-4381(2016)12-0107-11

國(guó)家自然科學(xué)基金資助項(xiàng)目(21276152)

2015-06-03;

2016-04-22

呂生華(1963-)，男，教授，博士生導(dǎo)師，主要從事氧化石墨烯的制備及復(fù)合材料的研究 ，聯(lián)系地址：陜西省西安市未央大學(xué)園區(qū)陜西科技大學(xué)資源與環(huán)境學(xué)院1B實(shí)驗(yàn)樓(710021)，E-mail:lvsh@sust.edu.cn