采用尿素-氯化胆碱DES辅助制备了铜负载的聚酰亚胺催化剂,并将其应用于光-芬顿降解甲基橙染料.其中,尿素-氯化胆碱DES可作为溶剂和去质子化试剂,使得铜能更好地负载到聚酰亚胺上.同时,通过SEM、XRD、红外光谱、EDS、TEM、XPS等手段对催化材料进行了表征,验证了铜的负载.进一步探究了催化剂用量、H2O2用量、pH、光照强度、初始浓度等条件对最终降解效率的影响,通过正交试验对实验条件进一步优化,得出甲基橙初始浓度为10 mg·L-1、pH=3、光照强度500 W、H2O2加量0.15 mL、催化剂用量为0.15 g时,可达到甲基橙的几乎完全降解.

综述了聚酰亚胺(PI)-金属复合催化材料的制备与应用技术,从二酐和二胺单体类型、金属离子种类及加入方式、亚胺化方法和制备条件等诸多角度分析了影响复合材料结构和性能的因素,基于电荷转移机制剖析了PI分子结构对所催化反应的协同促进作用.重点列举了PI-金属复合催化剂在光催化、电催化、Fenton氧化、Suzuki-Miyaura偶联、Chan-Lam偶联、加氢和环氧化等领域的应用实例,同时指出了目前存在的问题和应用前景.

建立低共熔溶剂萃取,气质联用法测定水中的萘、芴、芘的分析方法.对低共熔溶剂的种类、混合比例、萃取方式、萃取温度等萃取条件进行选择优化.实验结果表明:比例为3:2的薄荷醇和癸酸的低共熔溶剂,30℃下在酸性环境中以旋涡混合进行萃取,萃取剂用量为500μL效果最佳.该方法检出限为0.01 mg/L,加标回收率为81.15％～91.49％.应用该方法对水样进行分析,具有成本低、方便快捷、绿色环保等优点.

研究了尿素-氯化胆碱低共熔溶剂中催化合成酞菁铜的工艺.考察了反应温度、反应时间、原料配比和催化剂用量等因素对反应过程和酞菁铜收率的影响,提出了可能的反应机理.采用红外光谱(FT-IR)、紫外-可见光谱(UV-visible)、热重-差式扫描量热仪(TGA-DSC)和X射线衍射(XRD)表征了反应产物及中间体的分子结构.实验结果表明:尿素-氯化胆碱低共熔溶剂可起到溶剂、原料以及催化剂的三重作用,促进了酞菁环的形成,避免了使用传统工艺中所用的戊醇、三氯苯或高沸点烷基苯等有毒、有害有机溶剂,以及昂贵的1,8-二氮杂环[5,4,0]十一烯-7(DBU)有机碱催化剂,为酞菁铜的绿色合成和产物精制提供了有价值的信息.

为了降低生物柴油的生产成本、提高过程效率,研究了高自由脂肪酸油脂一步法制取脂肪酸甲酯的催化剂体系.提出水解-酯化耦合反应机理,建立拟均相催化反应动力学模型,并借助多物理场模拟软件COMSOL Multiphy-sics和流程模拟软件Aspen Plus 11对甘油水混合物与脂肪酸甲酯的分离过程和相平衡进行模拟研究.结果表明:采用十二烷基苯磺酸-硫酸催化体系,可在较温和条件下实现由脂肪酸-油脂混合物通过水解-酯化耦合一步法制取脂肪酸甲酯,产品收率达到96％以上.动力学模型分析表明,耦合过程水解和酯化的活化能分别为78.78 kJ/mol和68.7kJ/mol.针对烧瓶内酯化体系的分离过程模拟表明,甘油-水混合物与脂肪酸甲酯物料分离仅需10 s.相平衡模拟得出,甘油在两相间的分配系数超过10 000.

研究了尿素-氯化胆碱低共熔溶剂DES的制备方法.通过监控制备过程中折光率、电导率和密度等性质指标的变化,考察了尿素-氯化胆碱DES合成规律及影响因素.采用红外光谱表征了所合成DES的分子结构.使用AMS软件中COSMO-RS模块对DES其中的尿素和氯化胆碱分子中的表面电荷密度分布进行了模拟,剖析了氢键作用机制.比较了干法和湿法制备DES对所得产物性质的影响.针对湿法制备的实验结果表明,在氯化胆碱与尿素摩尔比1:2,第一阶段温度控制在80℃脱水,第二阶段温度控制在120℃深度脱水,所得DES与干法制备的DES主要性质指标相近.此外,湿法制备的DES不会出现干法放大制备时产物时常出现凝固的现象,为尿素-氯化胆碱低共熔绿色溶剂的工业化放大生产提供了一个新的思路.同时,以尿素-氯化胆碱DES为溶剂制备了铜锰金属氧化物前体,经煅烧后得到CuMn2 O4,且结晶度较好.

该文报道了以均苯四甲酸二酐(PMDA)和4,4′-二氨基二苯醚(ODA)为单体制备聚酰亚胺(PI)的清洁过程.首先,在N,N-二甲基甲酰胺(DMF)中获得聚酰胺酸(PAA);然后,以尿素-氯化胆碱低共熔溶剂(DES)为催化剂,乙酸酐为脱水剂,协同实现PAA亚胺化.所得产物PI可通过简单过滤分离.用FTIR、TGA-DSC和元素分析对PAA和PI的结构进行了表征.考察了反应时间、反应温度、DES催化剂与脱水剂用量对PAA亚胺化反应的影响.得到亚胺化最佳反应条件为:温度80℃,DES与乙酸酐体积比1:2、PAA与DES物质的量比1:2.红外表征结果证实了亚胺键的生成.此外,DES和DMF可重复使用,反应过程绿色,不使用有毒有害的吡啶、咪唑和喹啉类催化剂.

针对酯交换法合成生物柴油中均相催化剂不容易分离和非均相催化剂易失活和用量大等问题,提出用邻苯二甲酰亚胺钾催化大豆油和甲醇合成生物柴油.通过单因素实验考察了催化剂邻苯二甲酰亚胺钾用量、醇油摩尔比、反应温度和反应时间对甘油三酯转化率的影响,并利用Design-Expert软件通过响应面实验对合成反应条件进行了优化.考察了邻苯二甲酰亚胺钾在甘油和甲醇中的溶解度和作为催化剂的重复使用性能.通过红外光谱和气相色谱-质谱对生物柴油的结构和组成进行了分析.结果表明:合成生物柴油的最佳反应条件为反应温度60℃、醇油摩尔比7.15:1、反应时间2.4 h、催化剂用量1.2％,在此条件下甘油三酯转化率为96.0％;催化剂在高温下溶于甲醇和甘油,在低温下可在甘油中析出;催化剂循环使用4次,甘油三酯转化率仍在85％以上;红外光谱和气相色谱-质谱分析表明,生物柴油被成功合成,棕榈酸甲酯、油酸甲酯、亚油酸甲酯和硬脂酸甲酯含量为83.09％.综上,邻苯二甲酰亚胺钾作为合成生物柴油的催化剂,具有较高的催化性能和较好的重复使用性,可以实现均相酯交换反应和非均相分离.

The preparation of fatty acid methyl ester from soybean oil and methanol with potassium phthalimide as catalyst was proposed and studied. Based on quite different solubilities of potassium phthalimide catalyst in methanol and glycerol, a new homogeneous transesterification reaction and heterogeneous separation of the catalyst were realized. The transesterification reaction process was analyzed and optimized using response surface model. The solubilities of potassium phthalimide at different solvent and different temperatures were measured experimentally and calculated using COSMO-RS module in AMS software, respectively. A possible reaction mechanism and catalyst separation strategy was proposed. Potassium phthalimide exhibited such advantages as light color of product, easy separation of catalyst and efficient utilization of feedstocks over traditional potassium hydroxide catalyst. It can be reused as a catalyst for four times and still has a high catalytic activity. The catalyst has good stability and the recovery yield is above 90%.

研究了松油醇-月桂酸憎水性低共熔溶剂DES(deep eutectic solvent)的合成,采用红外光谱FT-IR和热重-差示扫描量热法TGA-DSC等手段对DES结构进行了表征,并测试了所合成DES的熔点、挥发性、憎水性和折光率,以及粘度和密度与温度的关系.实验结果表明,比例合适的松油醇-月桂酸DES不仅憎水性好而且粘度小、流动性好.红外光谱FT-IR数据显示,松油醇-月桂酸DES分子间形成了氢键.考察了憎水性松油醇-月桂酸DES萃取水溶液中丁醇的性能.实验结果表明,所合成憎水性DES对丁醇显示出较强的萃取能力.

Single-layer graphene has been proved to be an ideal material for broadband high-speed photodetector. However, the pure graphene photodetector photoresponsivity is limited to tens of mA/W by the low optical absorption and short exciton life of graphene. When higher responsivity is needed, the graphene layer needs to be coupled with other materials, e.g., Titanium Dioxide (TiO2). Conventional TiO2 recipes require either solution or high temperature which tends to destruct the graphene layer. In this work, TiO2 is synthesized by oxygen plasma treating Ti film. This novel synthesis route of TiO2 avoids defects introduced by the conventional recipes. The hybrid device shows a high photoresponsivity of ~ 179 A/W, a fast response time of ~ 20 ms and a specific detectivity of ~ 9.12 × 109 Jones with the incident light intensity of sub-microwatt. Under the illumination, the photon absorption in graphene creates electron–hole pairs, which were separated at TiO2/graphene interface by an internal electric field and corresponding electrons transfer from the graphene to TiO2 layer. The high photoresponsivity is attributed to the long lifetime of the photoexcited charge carriers caused by a built-in field at the interface of TiO2/graphene. Our research provides an effective method to improve the photoresponse of the graphene-based photodetector. In addition, our TiO2 recipe could be applied in the fabrication of other electronic devices where solution or high temperature processes are difficult.

综述了憎水性低共熔溶剂合成及应用的国内外研究状况.结合萜烯、季铵盐、长链脂肪酸和氯化胆碱等几大类憎水性DES的分子结构特点,比较并分析了氢键供体和氢键受体中不同官能团对亲脂性和憎水性的贡献.简述了不同系列憎水性DES的熔点、密度、粘度、折光率或电导率以及在水中的溶解性等理化性质特点.评述了不同系列憎水性DES在萃取水溶液中金属离子、农药和染料,植物中生物活性化合物以及分析化学中液-液微萃取制样等诸多萃取领域的应用技术状况和发展潜力.

Rod-like and mushroom-like Co3O4-CeO2 catalysts were synthesized using CeBTC MOFs as self-sacrifice templates. The two kinds of Co3O4-CeO2 catalysts with different shapes were characterized by SEM, TEM, N-2 physical-sorption, XRD, TPR, Raman, XPS. The effects of compositions and morphology on the catalytic activity were investigated. The catalytic activities of Co3O4-CeO2 are correlated with the results of SEM, TEM, N-2 physical-sorption, XRD, TPR, Raman, XPS to give insights into the catalytic sites. The results indicate the obtained Co3O4-CeO2 catalysts exhibit rod-like and mushroom-like, replicating the morphology of CeBTC templates. The catalytic activities of Co3O4-CeO2 were arranged in this sequence: Co1Ce > Co6Ce > Co2Ce > Co4Ce > Co8Ce, regardless their different catalyst morphology. The mushroom-like catalysts are superior to the rod-like ones due to their high surface areas and small Co3O4 crystal sizes. The sequence of catalytic activity versus Co/Ce ratio are coincidence with the order of Co-Ce synergistic interaction and Co3+/Co deduced from results of XRD, TPR, Raman, XPS. This evidence revealed that the Co-Ce synergistic interaction and Co3+ ions are responsible for the high activity of Co3O4-CeO2 catalysts. The highest CO conversion of 99% catalyst was achieved over M-Co1Ce catalyst with 12.5% CO2 and 15% H2O at 215 degrees C, 20,000 mL g(-1) h(-1). In addition, CO conversion of M-Co1Ce catalyst maintained more than 99% for 54 h in the atmosphere of simulated reformate at 20,000 mL g(-1) h(-1), suggesting the M-Co1Ce catalyst demonstrates potential in practice application.

石墨烯具有卓越的力学、电学、热学和阻隔性能,但疏水性、生物不相容性等缺点限制了其在诸多方面的应用.氧化石墨烯(GO)为石墨烯的衍生物,是一种新型的碳材料,边缘处具有羧酸官能团并且其表面含有羟基和环氧基团,具有良好的分散性、双亲性、生物相容性等性能,被视当代最具有发展前景的碳材料之一.本文简述了氧化石墨烯的结构模型、制备方法和官能团可控氧化石墨烯的制备,介绍了氧化石墨烯的性能和的应用进展,分析了氧化石墨烯在制备和应用方面的一些不足.最后,阐述了石墨烯未来面临的挑战以及潜在的发展前景.

研究了不同碳数双脂肪酸憎水性低共熔溶剂(HDES)的合成,测试了月桂酸-癸酸双脂肪酸HDES的密度、粘度,并考察了其对水溶液中铜离子的萃取效能.同时,考察了萃取溶剂量、水中铜离子浓度、萃取剂/水溶液配比和水溶液pH值对铜离子富集效率的影响.实验结果表明,当月桂酸与癸酸物质的量比为1:2、HDES与铜离子水溶液体积为1:1时,萃取后铜离子浓度从10-5 mg/L下降到1.6×10-6 mg/L,萃取效率达到91％,HDES的机械损失可以忽略.采用热重-差热分析仪(TGA-DSC)测试了月桂酸:癸酸双脂肪酸憎水性HDES的热稳定性.提出了脂肪酸络合金属离子、范德华(Van der Waals)力和其他弱相互作用辅助萃取铜离子的萃取机理.

通过碱法先将纤维素(CE)溶解,破坏其氢键,再通过交联技术和冷冻干燥技术制备得到具有很好成形性和柔韧性的纤维素气凝胶.将纤维素气凝胶与溶剂热法制备的超细氧化锌(ZnO)通过浸泡法进行复合,得到了CE/ZnO复合气凝胶.通过X射线衍射(XRD)、扫描电镜(SEM)和元素能量散射(EDS)技术对复合气凝胶进行了结构表征,证明了两者的复合是成功的.对复合气凝胶的抗菌性能进行研究,结果表明:随着ZnO用量的增加,复合气凝胶的抗菌性能也在提高.当纤维素气凝胶与ZnO的质量比为1∶2时,所得复合气凝胶CE/ZnO-O2O抗菌效果达到最好,抗菌率达到95.25％.

在实验装置上研究了乙二醇-氯化胆碱低共熔溶剂DES的合成过程.对比了乙二醇-氯化胆碱低共熔溶剂和乙二醇萃取剂破坏乙醇-水共沸物制备燃料乙醇过程的影响规律.分别考察了萃取剂加量和精馏过程回流比对塔顶乙醇纯度的影响.结果 表明,以乙醇-水共沸物为原料,使用乙二醇-氯化胆碱DES为萃取剂,在相同条件下比单独使用乙二醇萃取剂的塔顶乙醇浓度提高1.5％～2.6％,预测总能耗下降约25％.此外,DES的高沸点使过程更加经济和绿色化,避免了有毒乙二醇对环境的影响.与乙二醇萃取精馏流程相比,乙二醇-氯化胆碱DES可望实现工艺节能.

研究了氧化石墨烯(GO)催化果糖-氯化胆碱低共熔物脱水制取5-羟甲基糠醛(5-HMF)的反应过程.采用改进的Hummers法制备GO,通过FT-IR、XRD和SEM等手段对GO结构进行了表征.考察了原料量、催化剂量、反应温度和时间等对5-HMF产物收率的影响.结果表明:果糖与氯化胆碱形成低共熔溶剂提高了果糖与GO的接触效率,脱水速率显著提高;在温度110℃,反应时间4h,GO与果糖质量比为1:50的条件下,5-HMF液相色谱收率达到74.5％,几乎没有检测到副产物.GO分子中的羧基基团担负着果糖的脱水过程.GO循环使用六次,仍具有较好的催化效果,5-HMF收率基本不变,说明GO重复使用性能良好.

研究了氯化胆碱-尿素低共熔溶剂DES的公斤级放大制备规律.考察了物料配比、反应时间及反应温度对最终产品DES理化性质的影响,分别测定了合成过程中DES折光率、电导率和粘度等性质指标的变化,并通过FT-IR红外光谱分析了DES产品可能的化学结构.实验结果表明,在氯化胆碱与尿素的比例为1∶1时,不能生成DES;氯化胆碱与尿素比例为1∶1.5和1∶2时,均可生成DES;在比例为1∶2的条件下,60℃时不能生成DES,70、80和90℃时均可生成DES,且生成DES的时间随温度的升高而缩短.当DES折光率达到0.6时,其性质趋于稳定,可认为形成了结构稳定的DES.此外还发现,原料和产品中的水含量对DES产品的理化性质有一定程度的影响.本研究澄清了文献报道的DES理化性质存在差异的原因,为工业化放大生产氯化胆碱-尿素DES提供了基础数据.

The nano cellulose (nCE) was prepared by acid hydrolysis method, methacrylic acid (MAA) grafted nano cellulose hydrogel was prepared by using the free radical polymerization.Cellulose-based hydrogels with porous structure was applied to treat dye wastewater.The products were characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM).The influences of adsorption time, pH, initial dye concentration and adsorbent dosage on the dye removal efficiency were discussed.The adsorption mechanism was also discussed, and the pseudo-second-order model fitted MB adsorption better than the pseudo-first-order.The equilibrium adsorption isotherm was fitted to the Langmuir adsorption.The Langmuir isotherm model revealed that the maximum theoretical adsorption capacity of this hydrogel was 1250 mg·g-1.