氧化石墨烯改性水性半合成液压支架用浓缩液的制备与性能

通过化学法对氧化石墨烯（GO）中的羧基进行活化,然后在一定条件下使其与油酸三乙醇胺（MDLO）末端的羟基反应,制备GO接枝改性油酸三乙醇胺酯（MDLO-GO）;最后将水、KOH、EDTA混合均匀后再依次加入蓖钾皂、MDLO-GO、乳化剂及消泡剂等,制备得到GO接枝改性半合成液压支架用浓缩液（GO-HDSF）。红外光谱和X射线光电子能谱的测试结果表明GO被成功接枝到MDLO分子链上;此外,其他性能测试结果表明,随GO添加量增多GO-HDSF浓缩液黏度逐渐增大,且耐腐蚀性、润滑性逐渐提高;当GO的添加量为0.004%（质量分数）时,GO-HDSF的耐腐蚀电位增大到83mV,电流密度减小到6.5×10^-6A/cm²;GO-HDSF的最大无卡咬负荷PB值最大达到了481N。相比于未经氧化石墨烯改性的浓缩液,GO-HDSF的润滑性提高了11.9%,防腐蚀性提高了97.6%,同时耐高温、低温性能也显著提高。     

抗泥型低坍损聚羧酸减水剂的制备与性能研究

通过磷酸化异戊烯醇聚氧乙烯醚为大单体和引入乙烯基磺酸钠、丙烯酰胺、丙烯酸、丙烯酸羟丙酯等功能型小单体,在氧化-还原体系下合成了一种具有高含泥量下减水率高、混凝土经时损失小、硬化混凝土强度高、耐久性好的抗泥型低坍损聚羧酸减水剂。     

胺功能化氧化石墨烯对水泥基复合材料性能的影响

氧化石墨烯（GO）在水泥浆料中的团聚会影响其对水泥复合材料的力学增强作用。为了解决氧化石墨烯在水泥浆料中的分散性问题，用三乙醇胺（TEOA）通过化学法对氧化石墨烯进行胺功能化（TEOA-GO），并制备了氧化石墨烯水泥基复合材料（GO/C）和胺功能化氧化石墨烯水泥基复合材料（TEOA-GO/C）。分别采用X射线衍射（XRD）、扫描电子显微镜（SEM）、傅里叶红外光谱（FT-IR）等手段对样品结构进行表征。结果表明：与氧化石墨烯相比，胺功能化氧化石墨烯在氢氧化钙溶液中的分散性更好；水泥基复合材料的力学性能测定结果显示，当掺杂0.03%（质量分数）的胺功能化氧化石墨烯时，水泥基复合材料28 d抗折强度最大为7.96 MPa，相较于空白样和氧化石墨烯水泥基复合材料分别提高了15.3%和5.43%；当掺杂0.05%（质量分数）胺功能化氧化石墨烯时，水泥基复合材料28 d抗压强度最大为74.14 MPa，相较于空白样和氧化石墨烯水泥基复合材料分别提高了40.68%和11.99%；扫描电镜表征结果进一步表明，加入胺功能化氧化石墨烯，有利于提高水泥的水化程度，阻碍裂缝的扩展，提高水泥的力学性能。     

氧化石墨烯-水性环氧树脂固化剂的制备及性能

以三乙烯四胺（TETA）,氧化石墨烯（GO）,环氧树脂E44、三羟甲基丙烷三缩水甘油醚（TPEG）、甲基聚氧乙烯环氧基醚（MEH）和γ-(2,3-环氧丙氧)丙基三甲氧基硅烷（KH560）为原料,采用原位聚合法首先将TETA与GO球磨分散,使TETA与GO通过共价键相连,然后依次滴加E44、TPEG、MEH和KH560合成氧化石墨烯-水性环氧树脂固化剂（TGO-WPEA）,再与环氧树脂乳液（Epikote-6520）复合制得氧化石墨烯改性水性环氧树脂防腐涂料（TGO-EP）。通过FTIR、XPS和XRD对纳米材料进行结构表征,采用电化学测试和盐雾实验对复合涂层TGO-EP的防腐性能进行了研究。结果表明,固化剂分子通过共价键连接到GO表面,改善了GO在环氧树脂中的分散稳定性和接枝率,提高了TGO-EP复合涂料对腐蚀介质的屏蔽性能。与EP涂层相比,其腐蚀电位从-0.267mV提高到-0.125mV,腐蚀电流密度从5.44×10-8减小到1.09×10-8 A/cm2;EIS测试表明,浸泡20d后,TGO-EP仍具有最高的低频阻抗。     

不同长度侧链的梳状结构聚羧酸盐的合成及其对新拌水泥浆体性能的影响

通过自由基聚合反应合成了3组主链聚合度基本相同、侧链长度不同的梳状结构聚羧酸盐,对其表面张力和对水泥浆体流动性的影响进行了测试,并研究了其对硅酸盐水泥及添加不同品种和掺量的辅助性胶凝材料的水泥浆体的液相表面张力、流动性及Zeta电位的影响。结果表明:其它实验条件不变、主链聚合度相同的情况下异戊烯醇聚氧乙烯醚(TPEG)与α-甲基丙烯酸(α-MAA)的摩尔比从1:1增加到5:1,合成的聚羧酸盐的表面张力从47.70 m N/m降低至35.53 m N/m,添加到水泥净浆中时初始流动度从280 mm增大至310 mm;随着辅助性胶凝材料和聚羧酸减水剂掺量的增加,水泥浆体的液相表面张力减小、流动性增强;当水胶比从0.5降到0.3,水泥浆的Zeta电位呈现上升趋势,浆体稠度变大,Zeta电位变化更明显;水胶比为0.3时,水泥浆体的Zeta电位值随着辅助性胶凝材料和聚羧酸减水剂掺量的增加呈现下降趋势。     

基于PEI改性的WPU/石墨烯纳米复合乳液的研究

使用超支化型聚乙烯亚胺（PEI）对氧化石墨烯（GO）进行改性制得改性氧化石墨烯分散液（GO-PEI）;并在水性聚氨酯乳化过程中原位引入 GO-PEI分散液,并还原制备水性聚氨酯 /改性石墨烯纳米复合乳液（WPU/RGO-PEI）。通过红外光谱、紫外光谱、粒度分析、扫描电子显微镜和力学分析对 GO-PEI、复合乳液和复合膜的微观结构与性能进行了表征。结果表明： RGO-PEI在水性聚氨酯膜中均匀分散,当 RGO-PEI添加量为 7%时模量提高 12倍,添加量为 15%时表面电导率达 5.57×10^-4 S/cm。     

壳聚糖接枝聚丙烯酸/石墨烯复合水凝胶的制备及表征

首先采用改进的Hummers法制备氧化石墨烯,将壳聚糖溶解在乙酸溶液中,后加入引发剂过硫酸钾和单体丙烯酸,引发丙烯酸发生接枝聚合,将丙烯酸接枝聚合到壳聚糖上得到壳聚糖接枝聚丙烯酸（CS-g-PAA）。将CS-g-PAA分散在蒸馏水中,加入石墨烯（GO）形成分散液,最后采用戊二醛交联得到CS-g-PAA/GO复合水凝胶。水凝胶呈现纤维状,直径为723±125 nm。CS-g-PAA:GO从3:1降低到1:1,水凝胶的孔隙率和比表面积分别为从94.33%和55.31 m2/g增加至96.12%和60.90 m2/g。体外凝血实验表明,CS-g-PAA和CS-g-PAA/GO水凝胶均可促进血液凝结,相比较纯的CS-g-PAA,复合水凝胶中引入GO后,水凝胶的血液凝固指数（BCI）从65.12%降低到40.19%。主要归因于GO促进血小板聚集和CS-g-PAA/GO具有更强的物理吸收能力的结合作用。CS-g-PAA/GO复合水凝胶有望成为理想的止血材料。     

纳米复合粒子GO-g-PS改性SBS复合材料性能的研究

通过原位自由基聚合法在氧化石墨烯(GO)表面接枝聚苯乙烯(PS),制备纳米复合粒子GO-g-PS,并以此对苯乙烯-丁二烯-苯乙烯三嵌段共聚物(SBS)进行改性,研究其对SBS物理性能、热稳定性和动态力学性能的影响。结果表明:PS成功接枝到GO表面,生成GO-g-PS;当GO-g-PS质量分数为0.03时,GO-g-PS改性SBS复合材料的拉伸强度和拉断伸长率较高;与SBS和GO改性SBS复合材料相比,GO-g-PS改性SBS复合材料的物理性能、热稳定性和高温峰玻璃化温度均提高。     

原位自由基聚合法氧化石墨烯接枝聚氨酯的制备及其对EVA的改性研究

采用硅烷偶联剂KH570功能化氧化石墨烯(GO),再通过原位自由基聚合法在GO表面接枝聚氨酯(PU),得到GO接枝PU(GO-g-PU)复合纳米片,以其对乙烯-乙酸乙烯酯无规共聚物(EVA)进行改性。结果表明:GO-g-PU复合纳米片能均匀分散在EVA基体中,GO-g-PU/EVA纳米复合材料的物理性能与热稳定性能均优于EVA和GO/EVA复合材料。     

改性石墨烯/丙烯酸酯乳液的合成与性能研究

采用种子乳液聚合法,以甲基丙烯酸甲酯、丙烯酸丁酯、丙烯酸为单体,Tween80磺基琥珀酸二钠、OP-10和脂肪醇聚氧乙烯醚磺基琥珀酸单酯二钠为乳化剂,过硫酸铵、羟甲基丙烯酰胺为引发剂,先后合成出纯丙乳液、油酸-十二烷基硫酸钠改性氧化石墨烯/聚合物乳液和油酸-十二烷基硫酸钠改性石墨烯/聚合物乳液。聚合物乳液的结构和性能分析表明,油酸-十二烷基硫酸钠改性的氧化石墨烯或石墨烯成功地参与了乳液聚合中;改性氧化石墨烯/聚合物乳液或改性石墨烯/聚合物乳液的T_(d5%)和T_(d10%)差别不大,但均比对应的纯丙乳液的耐热性提高近50℃。     

Fabrication and characterization of graphene oxide modified polycarboxylic by in situ polymerization

Graphene oxide (GO) was modified by in situ esterification reaction with isopentenol polyoxyethylene ether (IPEG) to obtain GO precursor (GO-IPEG) with some polymerization activity. GO-modified polycarboxylic (GO-PCE) was prepared by GO-IPEG and acrylic acid (AA) using the method of in situ polymerization. The molecular structure of GO-IPEG and GO-PCE was characterized by Fourier transform infrared spectroscopy (FTIR), Raman spectra, and nuclear magnetic resonance (NMR). The dispersion properties and dispersion stability of GO-IPEG and GO-PCE in water solution were studied by ultraviolet–visible (UV–vis) absorption spectra, zeta potential, and atomic force microscope. The results of FTIR, Raman, ¹H-NMR, and ¹³C-NMR indicate that IPEG was successfully grafted onto the surface of GO and then fabricated with AA by in situ free-radical polymerization. The results of UV–vis and zeta potential show that GO nanosheets have a better dispersion in GO-IPEG or GO-PCE system when the reaction time of GO and IPEG is 1 h, and the dispersion stability can reach up to 1 month. The better dispersion and application property are confirmed by atomic force microscopy image and cement fluidity, water reducing rate, and compression strength. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48316.     

氧化石墨烯在水泥基体中的分散性及对其结构和性能的影响

为了解决氧化石墨烯(GO)纳米片层在水泥基体中的分散问题,制备了丙烯酸(AA)、丙烯酰氧乙基三甲基氯化铵(AAC)和丙烯磺酸钠(SAS)的共聚物(PAAS),PAAS与GO纳米片层形成PAAS/GO复合物并显示出分散作用。结果表明,w(PAAS)=2%分别与w(GO)=0.01%、0.02%和0.03%形成的复合物可使水泥基体分别形成由花状晶体、多面体状晶体和针状晶体构成的规整有序的微观结构,28 d时的抗折强度分别比对照样提高了63.0%、90.4%和87.9%,抗压强度分别提高了32.6%、74.2%和71.3%,同时这些水化晶体容易生长在裂缝、孔洞等缺陷处,具有修复结构缺陷的效果。PAAS通过与GO纳米片层形成复合物实现了GO在水泥基材料中的均匀分散以及对水泥基材料微观结构和性能的调控。     

Chemical Functionalization of Graphene Oxide by Poly(styrene sulfonate) Using Atom Transfer Radical and Free Radical Polymerization: A Comparative Study

Poly(sodium styrenesulfonate)-functionalized graphene was prepared from graphene oxide, using atom transfer radical polymerization and free radical polymerization. In atom transfer radical polymerization route, the amine-functionalized GO was synthesized through hydroxyl group reaction of GO with 3-amino propyltriethoxysilane. Atom transfer radical polymerization initiator was grafted onto modified GO (GO-NH₂) by reaction of 2-bromo-2-methylpropionyl bromide with amine groups, then styrene sulfonate monomers were polymerized on the surface of GO sheets by in situ atom transfer radical polymerization. In free radical polymerization route, the poly(sodium 4-styrenesulfonate) chains were grafted on GO sheets in presence of Azobis-Isobutyronitrile as an initiator and styrene sulfonate monomer in water medium. The resulting modified GO was characterized using range of techniques. Thermal gravimetric analysis, scanning electron microscopy, transmission electron microscopy, and atomic force microscopy results indicated the successful graft of polymer chains on GO sheets. Thermogravimetric analysis showed that the amount of grafted polymer was 22.5 and 31?wt% in the free radical polymerization and atom transfer radical polymerization methods, respectively. The thickness of polymer grafted on GO sheets was 2.1?nm (free radical polymerization method) and 6?nm (atom transfer radical polymerization method) that was measured by atomic force microscopy analysis. X-ray diffractometer and transmission electron microscopy indicated that after grafting of poly(sodium 4-styrenesulfonate), the modified GO sheets still retained isolated and exfoliated, and also the dispersibility was enhanced.     

In-situ graphene oxide reduction during UV-photopolymerization of graphene oxide/acrylic resins mixtures

The preparation of electrically conductive acrylic resins containing reduced graphene oxide (rGO) by photopolymerization is presented. The synthesis consists of a single-step procedure starting from a homogeneous water dispersion of GO, which undergoes reduction induced by the UV radiation during the photopolymerization of an acrylic resin. The role played by the amount of radical photoinitiator added to the resin has been evaluated in relation to the in-situ reduction of GO, that was monitored by X-ray photoelectron spectroscopy. Results show that the UV-induced photopolymerization of acrylic resins with added GO gives rise to conductive acrylic composites thanks to the simultaneous reduction of GO to rGO and crosslinking of the resin. On this basis UV-induced photopolymerization is proposed as a sustainable strategy for the production of conductive graphene/polymer composites.     

纳米二氧化硅/氧化石墨烯复合物对普通硅酸盐水泥力学性能的影响

氧化石墨烯(GO)在水泥中的分散性较差,限制了其提高水泥基复合材料性能。采用溶胶-凝胶法制备了纳米二氧化硅/氧化石墨烯复合物(GOS),在模拟的水泥孔隙溶液中对比了GO和GOS的分散稳定性;同时,制备了添加纳米片的水泥浆体,研究了GO和GOS对其力学性能的影响。结果表明:GOS在水泥环境中的分散稳定性明显优于GO;与对照组相比,GO/水泥基复合材料的28 d抗折和抗压强度分别提高了20.48%和13.14%,而GOS/水泥基复合材料分别提高了35.42%和23.90%。微观分析表明,GO/水泥基复合材料内部形成花状水化晶体,GOS/水泥基复合材料内部的水化晶体彼此交联,结构致密,降低了水泥脆性,提高了韧性。     

氧化石墨烯对水泥基复合材料微观结构的调控作用及对抗压抗折强度的影响

通过氧化法制备得到氧化石墨烯（GO），通过GO与丙烯酸（AA）和丙烯酰胺（AM）进行插层聚合反应制备得到插层复合物GO/P（AA-AM）。检测结果表明，GO在插层复合物中具有较小的尺寸和均匀的分布，将GO/P（AA-AM）掺入水泥基复合材料中，发现水泥水化产物成为规整的针状、棒状或多面体状晶体，并且能够聚集形成具规整形貌的微观结构和宏观结构，水泥基复合材料中的裂缝及有害孔洞比对照样品明显减少，其抗压强度和抗折强度比对照样品有明显提高。提出了GO纳米片层对于水泥基复合材料规整结构的调控机理，认为GO纳米片层及活性基团能够促进水泥化产物形成规整形状的水化晶体，最初形成的水化晶体成为后续水化晶体形成的模板，通过晶体的生长最终形成规整水化晶体及规整的微观结构和宏观结构。     

聚羧酸减水剂/氧化石墨烯复合物的制备与性能

通过氧化石墨烯（GO）与聚羧酸系减水剂单体甲基丙烯酸聚乙二醇单甲醚（MAAPEGME）、甲基丙烯酸（MAA）及甲基丙烯磺酸盐（SMAS）进行自由基共聚反应制备了氧化石墨烯与聚丙烯酸系减水剂（PCs）单体的共聚物（GO-PCs）,旨在解决GO掺入水泥基材料时存在的分散不均匀及流动性降低的问题,制备GO-PCs时各组分的质量比为m（MAAPEGME）: m（MAA）: m（MAS）: m（GO）=17:2:1:0.2。检测结果表明GO与单体之间发生了共聚反应,GO纳米片层均匀的分布PCs中,达到了GO在水泥材料中分布均匀、不影响水泥流动性及增强增韧的目的,SEM形貌说明GO-PCs对水泥浆体的微观结构有较好的调控作用,研究结果对于制备高性能长寿命混凝土具有积极的意义。     

氧化石墨烯改性热固性酚醛树脂的热性能研究

采用原位聚合法和溶液共混法制备氧化石墨烯(GO)改性热固性酚醛树脂,分析GO的加入量和加入方式对酚醛树脂热性能的影响。在原位聚合法制备的改性树脂中,GO的引入使酚醛树脂的Tg略有下降,随着GO加入量的增加,树脂的残碳率和第一阶段的热分解温度先升高后降低;相比于原位聚合法,溶液共混法制备的改性树脂中,树脂的耐热性更佳,GO的分散尺度更小。     

In situ Synthesis and mechanical,thermal properties of polyimide nanocomposite film by addition of functionalized graphene oxide

Polyimide (PI) and chemical modified graphene oxide nanocomposite films are prepared by in situ polymerization from solutions of pyromellitic dianhydride and 4,4′‐oxydianiline with various amount (0.5–2 wt%) of 3‐aminopropyltriethoxysilane (APTS) functionalized graphene oxide (GO) sheets in dimethylacetamide. The APTS functionalized GO (GO‐APTS) is a versatile platform for polymer grafting, improving excellent dispersion of GO in the PI matrix, and forming strong interaction with the PI matrix. The GO‐APTS/PI nanocomposites exhibited improvement in mechanical and thermal properties by addition of a small amount of GO‐APTS. With the addition of a small amount of GO‐APTS (1.5 wt%) to PI matrix, mechanical properties with the tensile strength and Young's modulus improved by 45% and 15%, respectively. The thermal analysis showed that the thermal stability of PI was slightly enhanced by the incorporation of GO‐APTS (1.5 wt%). This approach provides a strategy for developing high performance functionalized GO‐polymer composite materials. POLYM. COMPOS., 37:907–914, 2016. © 2014 Society of Plastics Engineers     

氧化石墨烯改性水泥砂浆抗氯离子渗透性能

采用快速电通量法及长期氯盐浸泡试验,研究了氧化石墨烯(GO)改性水泥砂浆的抗氯离子渗透性能,分析了电通量与表观氯离子扩散系数之间的关系,并通过扫描电镜(SEM)分析了其微观结构。结果表明:掺入适量的GO能够提升水泥砂浆的抗氯离子渗透性能,当掺量为0.06%(质量分数)时最显著,与无GO的对照组相比,水泥砂浆的电通量和氯离子侵蚀深度分别降低了34.5%和27.2%;长期氯盐浸泡60 d、120 d后,0~5 mm处的自由氯离子浓度最高分别降低了28.4%和15.3%;电通量与表观氯离子扩散系数之间存在良好的线性关系;GO有效调节了水化产物形状,减少了内部孔隙,使其微观结构更加密实,从而提升了水泥砂浆抗氯离子渗透性能。