TEPA-AM修饰的介孔材料吸附CO2性能的研究

将丙烯酰胺(AM)改性的四乙烯五胺(TE-PA)负载到介孔材料孔道内,形成氨基改性的CO2吸附材料。利用X射线衍射(XRD)、氮气物理吸附-脱附(BET)、红外等方法对样品进行了表征。通过动态吸附法研究了材料的CO2吸附和脱附性能,并与TEPA负载的吸附材料进行了比较。研究结果表明,在制备介孔分子筛MCM-41的过程中得到的一种结构规整度低的材料对TEPA-AM具有较好的分散性能,经过TE-PA-AM修饰的该材料表现出良好的CO2吸附性能,当TEPA-AM负载量达60%,该材料的吸附能力达到159.1mg/g;经过12次循环使用吸附量不下降。     

多胺基CO2吸附材料的制备

用纳米级SiO2负载胺化合物,制备CO2捕捉材料。测定了不同原料比例下该材料的吸水率,在饱和水蒸汽和干燥条件下对CO2的吸附量,以及它作为CO2气体吸附材料的重复使用和再生性能。研究结果表明,在饱和水蒸汽环境中,该吸附材料对CO2的吸附量远比干燥环境中的吸附量大的多,其中多胺基聚合物与SiO2比为20∶1时对CO2吸附量最大,可达到17mg/g。该吸附材料具有良好的重复使用及再生性能,经再生使用后,吸附量变化不大。     

氨基功能化硅胶的制备及其对CO_2的吸附性能

以乙醇胺(MEA)、二乙醇胺(DEA)、二乙烯三胺(DETA)和四乙烯五胺(TEPA)物理浸渍后的白色玻璃状无定型硅胶(Q)作为CO_2吸附剂,考察了有机胺负载量、有机胺分子链长短和羟基数量对CO_2吸附性能的影响以及吸附剂的再生性能。实验结果表明:50%TEPA-Q具有最大的CO_2吸附量,为2.589mmol/g。经过10次吸附-真空脱附循环后,50%TEPA-Q的CO_2吸附能力仅下降了8.034%,具有较好的循环稳定性。     

氨基改性CO2固体吸附材料的研究进展

以固态胺吸附剂和CO2吸附性能为主线,综述了改性剂的类型以及氨基负载的碳基、沸石、硅基、聚合物等CO2固体吸附剂的研究进展及优缺点,并对改性的硅基吸附剂的吸附性能的影响因素进行了讨论,如水的存在、温度以及CO2分压等,指出改性剂的选择以及分子筛的物理化学性质是未来CO2吸附的研究趋势.     

聚乙烯亚胺修饰的介孔材料对CO2的吸附性能

在MCM-41上负载修饰剂-聚乙烯亚胺(PEI),采用氮吸附、红外光谱和热重(TG)等手段表征材料的结构,利用静态吸附的手段测定其对二氧化碳的吸附性能.结果表明,PEI改性后的MCM-41材料对二氧化碳的吸附性能有了明显改善.MCM-41分子筛吸附量由改性前的8.8 mg/g增加到了改性后的90.2 mg/g.此吸附剂...     

P123对多孔TiN粉体孔结构及电化学性能的影响

以四氯化钛为钛源,P123为模板剂,氰胺为稳定剂,采用溶胶-凝胶法制备多孔TiO 2粉体,再经900℃氨气还原氮化得到多孔TiN粉体。通过XRD,SEM,BET,TEM和SAXD等表征粉体物相组成与微观结构,并采用循环伏安法、交流阻抗法和恒流充放电法测试其电化学性能。结果表明:合成粉体颗粒近似球形,为立方TiN相。相比之下,引入P123时所合成粉体中孔径尺寸为10~50nm的介孔数量增加,并存在孔径大小为2~3nm的微小孔道,同时孔道结构有序性有所提高,这有助于提升TiN粉体的电化学性能。因此,未加入P123合成TiN粉体的比电容仅为81F·g -1 ,内阻 R 1为1.1Ω,离子扩散阻抗 W 1为2.5Ω。引入P123合成TiN粉体的比电容提升到95F·g -1 , R 1和 W 1均有所减小,分别为0.9Ω和0.06Ω。     

活化介质对活性炭微结构及CO2吸附性能的影响

以煤质炭化料为原料,分别以水蒸气和CO2为活化介质制备出微孔结构发达的活性炭。利用N2吸-脱附等温线、碘吸附值、亚甲基蓝吸附值、CO2吸附容量、CO2解吸率和扫描电子显微镜(SEM)对其进行表征。结果表明,在实验室条件下,水蒸气法和CO2法制备样品的孔径均以0.5~1.0nm的微孔为主,在同等条件下,CO2法制备样品0.5~1.0nm范围的微孔含量要比水蒸气法制备样品多10 %以上。同时水蒸气法制备样品的中孔分布范围为2.0~3.0nm,CO2法制备样品中孔分布范围为2.0~2.5nm。在同等实验条件下,水蒸气活化制备出活性炭比CO2的孔径分布更广,活性炭的亚甲基蓝吸附值、碘吸附值及CO2解吸率更高,而CO2法制备出的样品对CO2的吸附容量更大。     

模拟油田环境中P110钢的CO2腐蚀行为

运用腐蚀失重和电化学测量技术,研究模拟油田环境中P110油井管用钢的CO2腐蚀行为.研究结果表明:随着试验时间的延长及腐蚀产物膜的形成,平均腐蚀速率逐渐降低,在试验时间达到72h后,腐蚀速率降低的趋势变缓,腐蚀产物膜下出现典型的局部腐蚀形貌;试样的自腐蚀电位Ecorr升高,腐蚀电流icorr减小,腐蚀速率降低.P110钢的阴极Tafel区出现明显的扩散特征;在反应初始阶段EIS具有两个时间常数,随着腐蚀的进行,腐蚀产物膜越来越厚,越来越致密,EIS的低频端出现Warburg阻抗与容抗的叠加,自腐蚀电位下的电极反应属于混合控制.     

P110钢CO2腐蚀产物膜的XPS分析

为了确定CO2腐蚀产物膜的组成及不同层次结构中成分和含量的差异,采用P110钢在高温高压腐蚀静态釜中制备CO2腐蚀产物膜,利用扫描电子显微镜(SEM)观察了腐蚀产物膜的表面和断面形貌,借助X射线衍射(XRD)的辅助,通过X射线光电子能谱(XPS)分析和研究了两层结构膜的化学组成差异.结果表明,腐蚀产物膜断面呈现双层结构;膜层的主要成分是FeCO3,还有少量的CaCO3和铁的氧化物,但内层CaCO3较多且夹杂着Fe3C和单质铁,外层氧化物稍多;通过内外层Ca2+含量差异推断内层腐蚀膜优先形成.     

Synthesis of magnetic chelating resins functionalized with tetraethylenepentamine for adsorption of molybdate anions from aqueous solutions

Magnetic resins were synthesized through polymerization of glycidyl methacrylate (GMA) in the presence of divinylbenzene (DVB) or N,N′-methylenebisacrylamide (MBA) as hydrophobic or hydrophilic crosslinker, respectively and in presence of suspended magnetite particles. The resins containing (DVB or MBA) as crosslinker were immobilized with tetraethylenepentamine (TEP) to give the amino resins, GMA/DVB/TEP (R1-en) and GMA/MBA/TEP (R2-en), respectively. The uptake behavior of the two resins was studied towards molybdate anions and uptake capacities of 4.24 and 6.18 mmol/g [as (Mo(VI)] were obtained using (R1-en) and (R2-en). Kinetic studies showed that the adsorption followed the pseudo-second-order model pointing the influence of the textural properties of the resin on the rate of adsorption. Thermodynamic data indicated an endothermic adsorption process. The uptake of Mo(VI) and regeneration of the resins were also studied using the column method. Regeneration efficiency up to 90–96% was reached using ammonia buffer.     

Facile preparation of N-doped porous carbon and its CO2 gas adsorption performance

Journal of Materials Science - Although carbon material are widely used for gas separation and adsorption due to its well-developed pore structure, their prevalent wide pore size distribution and...     

聚醚/二苯甲酮类紫外吸收基聚硅氧烷应用性能研究

对有机硅抗紫外线整理剂侧基聚醚/二苯甲酮类紫外吸收基聚硅氧烷(PE-PUVSi)在100%棉布上的应用性能进行了研究.结果表明:经PE-PUVSi整理后的棉织物具有明显的抗紫外效果,柔软性能有很大改善.研究还发现,PE-PUVSi中二苯甲酮紫外吸收基(UV)质量分数由4.67%增至26.58%时,整理后织物的紫外光透过率由71.0%降至38.1%,但整理后织物的吸湿性下降,白度变略有下降.柔软性能在UV质量分数为19.29%时达到最好,此时紫外光透过率为43.6%.     

MOFs材料改性及其吸附二氧化碳的研究进展

化石燃料燃烧后产生的二氧化碳气体的大量排放引起了人们的极大关注.CO2吸附捕获具有技术可靠、成本低等特点,应用前景广阔.金属有机骨架材料(MOFs)具有良好的化学稳定性和热稳定性,以及独特微孔结构而成为一种高效的CO2吸附材料.重点介绍了使用MOFs进行CO2吸附捕集的最新研究进展,总结了MOFs材料的制备、改性方法及...     

磷铁和碳酸锂制备LiFePO4的反应机理和性能研究

采用碳热还原法以磷铁和碳酸锂为原料合成了LiFePO4,用XRD、恒流充放电法和EIS对其进行表征,用TG-DTA分析了反应过程。预焙烧过程中磷铁中的磷与碳酸锂反应形成Li4P2O7和LiFeP2O7,再与中间产物Fe2O3、Fe3O4和补充磷源NH4H2PO4进一步反应生成LiFePO4。产物具有良好的电化学性能,在0.1C时放电容量可以达到151.68mAh/g,0.2和0.5C分别循环10和20次后放电容量仍有125.94和103.51mAh/g,衰减率分别为4.23%和7.24%。不同荷电状态的EIS结果表明:放电至2.4V具有最小的溶液阻抗;界面阻抗由于充放电至3.4V时包括一部分不稳定的SEI膜,因此比充放电至2.4V时大;随着充放电过程的继续,反应过程由反应控制逐渐变为扩散控制。     

Nanomaterials for adsorption and conversion of CO2 under gentle conditions

Global warming effect caused by excessive emission of greenhouse gases, such as CO₂ from modern industries, are emerging as serious environmental problem nowadays. Many strategies have been developed to address this issue, including solar energy utilization, green plants cultivation and coal desulfurization. These existing strategies always need sophisticated equipment and harsh reaction conditions, and are usually with limited efficiency. With the development of nanoscience and nanotechnology, it is becoming an effective strategy to directly capture and convert CO₂ with nanomaterials into valuable chemicals under gentle conditions. Herein, we summarize recent progress on nanomaterials for adsorption and conversion of CO₂ under gentle conditions, including various physical and chemical processes, and artificial photosynthesis. Future perspective and research direction of nanomaterials for CO₂ adsorption and conversion have been put forward on the basis of existing research works and our experimental experience.     

高性能双网络PAM/P123凝胶电解质的制备及其在二次Zn-MnO_(2)电池中的应用EI北大核心

柔性能量存储设备处于下一代电源的最前沿,其中最重要的组件之一就是凝胶电解质。采用自由基聚合法制备PAM/P123锌离子电池用双网络凝胶电解质,结果表明:加入少量三嵌段共聚物P123,宏观上提高凝胶电解质的抗拉强度、韧性和抗压强度,同时微观上使凝胶骨架形成0.6μm的中孔并提高表面孔分布密度,进而提高了电解液的浸润性。PAM/P123系列电解质不仅具有高平均溶胀率,而且在-30~65℃范围内电导率均高于纯PAM电解质。其中PAM/P123-2性能最佳,具有1920.79%平均溶胀率,且在0℃时的离子电导率为36.2 mS·cm^(-1)。使用该凝胶电解质制备的柔性准固态Zn/MnO_(2)电池在0℃下充放电稳定,1000周次循环后容量保持率达82.39%。     

功能化石墨烯-SiO2协同增强增韧聚丙烯复合材料的制备与性能

先采用溶胶-凝胶法制备了氧化石墨烯（GO）-SiO₂杂化材料,再与聚丙烯（PP）进行熔融共混制备了GO-SiO₂/PP复合材料。分别采用FTIR、XRD、XPS、DSC、SEM、动态热机械分析（DMA）、拉伸及冲击等测试手段对填料及GO-SiO₂/PP复合材料的结构与性能进行了表征。FTIR和XPS分析表明,GO已经成功获得功能化。力学性能测试结果证实,GO-SiO₂对PP基体具有良好的强韧化协同改性作用,且优于SiO₂/PP及GO/PP复合材料体系。固定GO-SiO₂中GO与SiO₂的质量比为1∶1,当填料GO-SiO₂的质量分数为0.1wt%时,GO-SiO₂/PP复合材料的拉伸强度和冲击强度分别为38.9 MPa和7.6 kJ/m²,与纯PP基体相比分别提高了29.4%和66.3%。DSC测试表明,GO-SiO₂/PP复合材料中PP的熔融温度和结晶温度分别为167.4℃和111.7℃,与纯PP相比分别提高了4.7℃和5.2℃。DMA测试表明,GO-SiO₂的加入使GO-SiO₂/PP复合材料的储能模量增大,损耗模量峰向更高温度移动。SEM观察表明,当加入少量的GO-SiO₂时,填料能均匀的分散在基体中,但GO-SiO₂过多时,则容易形成团聚。     

Crystallization kinetics of amorphous Ni78P22 powders and hydrogen adsorption on both amorphous and crystal alloy powders

A thermal and kinetic investigation of the behaviour of amorphous and crystal powder alloy Ni₇₈P₂₂ was performed in a hydrogen atomsphere. It was shown that the amorphous alloy absorbs hydrogen within the temperature range 393 to 520 K. After that it is transformed into the crystal (stable) state in two steps at 615 and 670 K, respectively, thus forming stable Ni and Ni₃P phases. The crystal form of the same sample also adsorbs hydrogen, but at lower temperatures ranging from 310 to 520 K, The activation energies of the crystallization process, as well as the frequency factors, the rate constants and the enthalpy of crystallization were determined. Both kinetic and thermal parameters of the hydrogen adsorption process taking place in at least two steps, as in the crystallization process, were also determined.