采用模板法制备块状炭纳米材料的研究

采用四重高吸水树脂作有机模板,葡萄糖为炭源制备了新型块状纳米炭材料,研究了四重高吸水树脂的高分子网络结构及葡萄糖溶液的浓度对新型纳米炭材料微观结构的影响.研究结果表明:葡萄糖的浓度对所制备的炭材料的微观结构有较大的影响.     

三维有序大孔炭材料制备与结构表征

本文以蔗糖为炭源,以二氧化硅胶晶微球为模板,利用胶晶模板法制备了具有微观上具有三维有序大孔结构的新型炭材料,并利用SEM、TEM、XRD、BET等手段对制备样品进行了表征。研究结果表明,当蔗糖浓度为30%时,制备的大孔炭材料结构完整、尺寸均一、三维结构长程有序,是一种具有多级孔结构的新型炭材料,在环境保护、分子催化、分子吸附、电化学等领域具有一定的应用前景。     

中科大俞书宏团队《先进材料》:超弹性硬炭气凝胶

<正>最近,中科大化学系俞书宏教授领导的课题组受到自然界的蜘蛛网同时具有高强度和弹性的启发,巧妙通过模板法构筑纳米纤维网络结构,赋予传统硬炭材料超弹性。通过使用间苯二酚-甲醛(RF)树脂作为碳源,以多种1D纳米纤维,包括细菌纤维素纳米纤维(BCNF),碲纳米线(TeNW)和碳纳米管(CNT)作为结构模板制备RF的纳米纤维气凝     

介孔炭的制备与表征

文章采用硬模板法,通过选取蔗糖、糠醇、萘作为不同的碳源和不同的模板剂,控制模板剂投加量、碳化时间工艺条件,制备介孔炭材料,结合SEM、BET等分析测试手段,探究不同条件对介孔炭材料的形貌和孔径的影响,为实现孔径可调提供数据基础。结果表明:采用SBA-15为模板剂、蔗糖为碳源、1.5 g的模板剂投加量,6 h的碳化时间,制备出较大的比表面积及孔容孔径,呈有棒状排列的有序介孔炭材料特征。     

工艺参数对天然沸石模板多孔炭结构的影响

以内蒙古赤峰市的天然沸石矿为模板，以蔗糖为炭的前驱体，制备了具有较窄中孔孔径分布的模板多孔炭。利用SEM、XRD及N2吸附等方法对模板炭进行了表征。采用BJH法分析了模板炭的孔径分布特征。研究了制备工艺中催化剂H2SO4的用量和炭化温度对所得模板多孔炭结构的影响。结果表明，硫酸用置和炭化温度对模板多孔炭的表面形貌、微晶结构和孔结构都有一定的影响。催化剂H2SO4用置过多时模板炭表面结构粗糙、致密，杂质较多，比表面积和总孔容较小；炭化温度越高，模板炭的结构收缩越严重，总孔容和中孔孔容越大，中孔率越高。     

秸秆基炭/高吸水树脂缓释尿素的制备及缓释性能研究

以水稻秸秆碳化后的生物质碳为原料,吸附尿素制得尿素-秸秆炭。以丙烯酸为单体,N,N'-亚甲基双丙烯酰胺为交联剂通过溶液聚合法在常温下制备秸秆基炭/高吸水树脂缓释尿素。可以通过在尿素-秸秆炭外包覆一层乙基纤维素进一步提高其缓释性能。高吸水树脂的三维网络结构可以对包覆在内部的养分起到缓冲作用,防止养分的迅速流失,造成浪费,提高肥料的利用率,在未来农业上有良好的发展前景。     

介孔分子筛的添加对PE基复合材料性能的影响

用熔融共混法制备出聚乙烯基纳米复合材料.研究了填充介孔分子筛MCM-41(带模板和无模板)颗粒以及不同的填充颗粒含量对复合材料拉伸性能的影响.结果表明,这种具有独特有机-无机复合结构的纳米介孔分子筛MCM-41(带模板)直接作填料,能与基体形成新型网络复合结构.因此,在MCM-41(带模板)的质量分数为2.5%时,复合材料的拉伸强度达到最大值,比基体树脂提高43.5%,弹性模量提高了50%;用MCM-41(无模板)作填料,在其质量分数为2.5%时,复合材料的拉伸强度达到最大值,比基体树脂提高52%,弹性模量提高了106%.     

溶胶凝胶法多孔炭材料的制备及其表征

以十六烷基三甲基溴化胺(CTAB)稳定过的商业硅溶胶为模板硅源、蔗糖为炭前体、运用溶胶凝胶法制备了多孔炭材料。并采用低温N2等温吸脱附、X射线衍射等对材料的结构进行了测试与表征。结果表明:CTAB的加入使所得的多孔炭孔径分布更加集中,由于炭化温度较低,所得的炭材料仍为无定形结构。     

TiO_2/淀粉基高吸水树脂的制备及降解性能研究

采用反相悬浮聚合法,在淀粉基高吸水树脂上负载纳米二氧化钛粒子制备无机有机复合高吸水树脂。对复合树脂的微观形貌和吸液性能、保水性能和降解性能进行了表征。扫描电镜证实了纳米TiO_2成功负载在高吸水树脂表面,具有良好的微观网络空间结构;实验条件下改性纳米TiO_2占单体用量5.0%左右时复合树脂吸液能力最佳;复合树脂在室温和较高温度下均具有良好的保水率;TiO_2的负载能有效提高高吸水树脂的紫外光降解性能,紫外光照射48h降解率高达94.3%。     

紫外光引发制备PAA/CMC高吸水树脂及性能研究

以羧甲基纤维素钠(CMC)为骨架,通过紫外光引发聚合将单体丙烯酸(AA)接枝到CMC骨架上,合成PAA/CMC高吸水树脂。采用单因素实验法优化并确定了具有最高吸水能力的树脂的最佳制备条件。结果表明,合成树脂的最优条件为：CMC用量为0.05 g, AA质量浓度为0.48 g/mL,中和度为40%,引发剂和交联剂的用量分别为AA质量的0.3%和0.05%,反应时间55 min。所制备的高吸水树脂在蒸馏水中的最大吸水倍率为1 281.21 g/g,在生理盐水中的最大吸水倍率为69.42 g/g。采用红外、热重以及扫描电镜对树脂的结构进行表征。结果表明,该制备方法成功合成了PAA/CMC高吸水树脂,其具有较好的热稳定性,树脂表面有明显的褶皱结构,具有吸水速率快、保水性好等特点。     

Easy preparation of carbon sheets with controlled microstructures from sucrose/layered superabsorbent polymer hydrogels

An easy method is described for fabricating carbon sheets with nanostructures using sucrose as a carbon precursor and a layered superabsorbent polymer (LSAP) as a structure-directing agent. The method is based on the interaction of the three-dimensional polymer networks of the LSAP with a sucrose solution in the hydrogel cells. The synthesis scheme consists of: (a) preparation of the LSAP, (b) preparation of layered hydrogels by immersing the LSAP in the sucrose solution for 2 days, (c) carbonization of the layered hydrogels containing the sucrose solution. The synthesized carbon sheets show different microstructures including petal-like, regular and interleaved types, which can be controlled by simply adjusting the initial concentration of the sucrose solution in the hydrogel cells. Moreover, a formation mechanism for the carbon sheets is proposed.     

溶胶-凝胶法制备中孔炭材料及其表征

以正硅酸乙酯为无机模板硅源，蔗糖为炭前驱物，采用溶胶-凝胶法制得了比表面积达1073．36m^2／g，孔径分布集中，平均孔径为2．75nm的中孔炭材料，并采用FT—IR、N2吸附、TG—DTA和XRD等分析手段对其进行了表征。     

玻璃化法提高介孔炭抗氧化性研究

以SBA－15为模板,蔗糖为炭源,制备了CMK－3介孔炭材料。采用磷酸一磷酸盐溶液对介孔炭进行浸渍,在N2保护、高温条件下进行玻璃化处理。考察了玻璃化方法对活性炭和介孔炭的抗氧化性的影响。结果表明,玻璃化可以显著提高炭材料的抗氧化性。考察了玻璃化条件包括浸渍液与介孔炭的配比及玻璃化温度对介孔炭抗氧化性的影响。结果表明,玻璃化介孔炭的失重率随着浸渍液配比的增加先降低再升高,适宜配比为1：7,玻璃化介孔炭的失重率随着玻璃化温度升高先降低再升高,适宜的玻璃化温度为700℃,     

Porous concrete as a template for the synthesis of porous carbon materials

The potential of industrial porous concrete for using as a template for the synthesis of porous carbon materials has been investigated. Carbon replicas of porous concrete have been prepared by carbonization of sucrose. The pores of the resulting carbon materials range from the macropore to the micropore region, pointing to a hierarchy.     

Controlling the textural parameters of mesoporous carbon materials

The mesoporous carbon materials prepared by inorganic templating technique using mesoporous silica, SBA-15 as a template and sucrose as a carbon source, have been systematically investigated as a function of sucrose to mesoporous silica composition, with a special focus on controlling the mesoporous structure, surface morphology and the textural parameters such as specific surface area, specific pore volume and pore size distribution. All the materials have been unambiguously characterized by XRD, N₂ adsorption–desorption isotherms, high-resolution transmission electron microscopy, high-resolution field emission scanning electron microscopy, and Raman spectroscopy. It has been found that the porous structure, morphology and the textural parameters of the mesoporous carbons materials, CMK-3-x where x represent the sucrose to silica weight ratio, can be easily controlled by the simple adjustment of concentration of sucrose molecules. It has also been found that the specific surface area of the mesoporous carbon materials systematically increases with decreasing the sucrose to silica weight ratio. Moreover, the specific pore volume of the materials increases from 0.57 to 1.31 cm³/g with decreasing the sucrose to silica weight ratio from 5 to 1.25 and then decreases to 1.23 cm³/g for CMK-3-0.8. HRTEM and HR-FESEM also show a highly ordered pore structure and better surface morphology for CMK-3-1.25 as compared to other materials prepared in this study. Thus, it can be concluded that the sucrose to silica weight ratio of 1.25 is the best condition to prepare well ordered mesoporous carbon materials with good textural parameters, pore structure and narrow pore size distribution.     

Molecularly imprinted polymer microspheres prepared by precipitation polymerization using a sacrificial covalent bond

Molecularly imprinted polymer microspheres were prepared by precipitation polymerization using a sacrificial covalent bond. In the present model, cholesteryl (4‐vinyl)phenyl carbonate was used as a template monomer. The imprinted microspheres were prepared using ethylene glycol dimethacrylate (EDMA) and divinylbenzene (DVB) as crosslinker. The base‐labile carbonate ester bond was easily hydrolyzed to leave imprinted cavities in the resulting polymers. Radioligand binding analysis, elemental analysis, and scanning electron microscopy were used to characterize the imprinted materials. Imprinted microspheres prepared from DVB crosslinker had larger and more defined spherical shape, and displayed better imprinting effect than did the EDMA‐based microparticles. For comparison, imprinted bulk polymers were also prepared in the same reaction solvent as that used in precipitation polymerization. Elemental analysis results indicated that imprinted microspheres contained more template monomer units than bulk materials. The efficiency of template removal by hydrolysis treatment for microspheres was also higher than that for bulk polymers. For DVB‐based polymers, imprinted microspheres displayed higher specific cholesterol uptake than did the corresponding bulk polymer. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1390–1398, 2006     

Fe_3O_4/介孔碳复合体的合成及其处理罗丹明B废水的应用

以介孔SBA-15为硬模板,利用硝酸铁和蔗糖一步浸渍的方法,通过纳米刻蚀合成了Fe3O4与介孔碳纳米粒子复合体（Fe3O4/介孔碳复合体）,对复合体进行吸附有机染料罗丹明B的磁性分离研究,实验表明,Fe3O4/介孔碳复合体有较好的吸附分离性能。     

Preparation and adsorption properties of a novel superabsorbent based on multiwalled carbon nanotubes–xylan composite and poly(methacrylic acid) for methylene blue from aqueous solution

A novel superabsorbent was prepared by the copolymerization reaction between multiwalled carbon nanotubes (MWCNTs)–xylan composite and poly(methacrylic acid) (PMAA) in the presence of N,N′‐methylenebisacrylamide as cross‐linker and the redox initiation system (NH)₄S₂O₈‐anhydrous Na₂SO₃ as initiator for adsorbing methylene blue (MB) from aqueous solution. First, covalent modification of MWCNTs with a natural polymer xylan was achieved by the nucleophilic substitution reaction. The obtained xylan modified MWCNTs–xylan composite was characterized by transmission electron microscope, Fourier transform infrared spectroscopy, X‐ray photoelectron spectrometer, and thermal gravimetric analysis. The results indicated that the hydroxyl groups of xylan participated in the formation of MWCNTs–xylan composite, and MWCNTs–xylan composite contained 32% xylan and about four molecule chains of xylan were grafted onto 5,000 carbon atoms of MWCNTs sidewalls. Subsequently, a novel superabsorbent based on MWCNTs–xylan composite and PMAA was prepared and characterized by Fourier transform infrared spectroscopy, scanning electron microscope, and swelling test. The results proved that superabsorbent was successfully prepared by copolymerization reaction and found that the superabsorbent evidently presented three‐dimensional network structure. Swelling process of superabsorbent complied with the Fick's law. Adsorption property of superabsorbent for MB was also systematically studied by investigating these parameters, such as superabsorbent dosage, initial MB concentration, contact time, ion strength, and pH. The superabsorbent presented a higher adsorption capacity and removal rate for MB. The adsorption data were fitted by Langmuir, Freundlich isotherm models, and four adsorption kinetic models. Freundlich isotherm model better fitted the equilibrium data than Langmuir, and adsorption kinetics could be well described by pseudo‐second‐order kinetic and intraparticle diffusion. These results indicated that the superabsorbent can be used as an efficient absorbent for removal of MB from aqueous solution. POLYM. COMPOS., 35:1516–1528, 2014. © 2013 Society of Plastics Engineers