共查询到19条相似文献,搜索用时 140 毫秒
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利用不同质量分数的石墨烯(MLG)与13X/LiCl合成新型复合吸附剂。通过扫描电镜(SEM)和N2吸附表征复合吸附剂的微观形貌和孔隙特性,测试了复合吸附剂开式环境下的水蒸气吸附及解吸性能,并探究复合吸附剂中石墨烯质量分数对吸附解吸性能的影响。通过80%相对湿度(RH)的高湿工况进一步筛选出盐的质量分数为18.4%的13X/LiCl为最佳盐含量的吸附剂(MZ)作为合成复合吸附剂的基质。实验结果表明:石墨烯增加了复合吸附剂的结构性参数(比表面积,孔体积及孔径),其中比表面积由未添加石墨烯的MZ [(262±3)g/m2],最大可提升至12G-MZ [(304±4)g/m2];复合吸附剂表现出优异的水蒸气吸附性能,所有复合吸附剂的相对吸附量均高于MZ(0.554g/g),3G-MZ吸附性能最佳,水蒸气吸附量高达0.587g/g,是13X的2.7倍;除12G-MZ外,随着吸附剂中石墨烯质量分数的增加,水蒸气解吸率随之增加,其中9G-MZ的解吸率接近90%,较MZ(81.8%)提升了9.7%。该研究可为复合吸附剂应用于吸附空气取水提供基础研究数据。 相似文献
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碳纳米管对铅离子的吸附性能研究 总被引:2,自引:1,他引:1
采用几种不同来源的碳纳米管进行铅离子的吸附实验,并用活性炭进行对比实验,从管径、比表面积、孔体积等几个方面分析不同来源碳纳米管吸附量差异的原因,考察对碳纳米管吸附量的影响。结果表明:实验所用三种来源碳纳米管的对铅离子的吸附均能在较短的时间内达到吸附平衡,碳纳米管单位比表面积的吸附量是活性炭的十几甚至几十倍.吸附能力均优于活性炭的吸附能力,在吸附方面具有明显的优势;不同来源碳纳米管的吸附量主要由其管径和开口率所决定。管径越小,开口率越大,则比表面积越大,吸附量也越大:碳纳米管吸附铅离子的过程为放热过程,在低温下有利于铅离子的吸附。这些结果为碳纳米管在金属离子吸附方面提供了基础数据。 相似文献
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以硝酸钙和磷酸氢铵为原料,采用化学沉淀法成功合成羟基磷灰石(HAP),并将其与腐植酸(HA)复合,制备出复合吸附剂HAP-HA。通过傅里叶变换红外光谱(FT-IR)、比表面积及孔径分析、差热-热重分析(TGDSC)及扫描电镜(SEM)等方法对样品进行表征。结果表明:腐植酸成功负载到羟基磷灰石上;HAP-HA孔径主要分布在3~5 nm,比表面积较大,且具有较好的稳定性;HAP-HA表面粗糙不平、孔隙较多,这增大了比表面积,为重金属离子提供了大量的活性位点。以Mn(Ⅱ)为目标污染物,将Mn(Ⅱ)的去除率作为指标,通过吸附实验考察吸附剂HAP-HA对污染物的吸附性能。结果表明:在常温、pH为8.0、投加量为0.15 g、吸附时间为150 min的条件下,吸附剂HAP-HA对Mn(Ⅱ)的去除率最高,可稳定达到99.0%以上;该吸附过程符合Freundlich等温吸附模型。同时,对吸附后的吸附剂进行脱附及再生吸附实验,以NaOH溶液作为洗脱剂可取得较好的脱附效果,脱附效率可达78.1%,再生循环吸附6次后HAP-HA仍具有良好的吸附性能。 相似文献
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采用硝酸铝为铝源,碳酸铵为沉淀剂,聚乙二醇(PEG1450)为模板剂,合成廉价的有序介孔氧化铝
(OMA)作为吸附剂载体。以2-氨基-2-甲基-1-丙醇(AMP)为氨基化表面修饰剂,对OMA采用过量浸渍法进行表面氨基化,制备一种高性能低成本的二氧化碳吸附剂OMA-AMP。通过BET法比表面积测定、X射线衍射(XRD)、透射电镜(TEM)、红外光谱(IR)等表征方法对改性前后吸附剂的比表面积、孔结构等特性进行表征,结果表明制备的
OMA-AMP具有比表面积大、孔径分布窄、孔结构有序等特点。利用模拟烟道气,从浸渍时间、吸附床层温度、气体流量以及AMP浓度4个变量考察吸附剂的性能。结果表明,OMA经过质量分数为50%的AMP浸渍12 h,在吸附温度为70 ℃、气体流量为40 mL/min条件下,OMA-AMP对二氧化碳的吸附量高达84.15 mg/g;吸附剂吸附性能较稳定,再生容易且效果良好;吸附剂制备成本低廉,吸附效率高。该吸附剂可以解决在二氧化碳捕集技术中成本居高不下的问题,在工业上具有实际应用价值。 相似文献
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利用乳液法制备多孔石墨烯气凝胶(emGA),改变乳液油水比制备不同的emGA。扫描电子显微镜(SEM)、傅里叶红外光谱(FTIR)、氮气吸附脱附等表征显示,emGA具有多孔结构,经水热还原后含氧官能团大部分被除去,比表面积为103.3~243.1m2/g。以亚甲基蓝(MB)浓度和温度作为变量,考察emGA对水中MB的吸附效果。结果表明,emGA的比表面积越大,其对MB平衡吸附量越大;当初始浓度越大,温度越高,则吸附有利。吸附动力学数据表明emGA吸附MB符合准二级动力学模型和内扩散模型,吸附过程分为大孔扩散和微孔扩散。吸附等温线数据拟合结果符合Langmuir模型,表明emGA对MB的吸附属于单分子层吸附。Langmuir模型计算出emGA-2饱和吸附量为307.7mg/g,与实验值291.3mg/g较为接近。分析热力学参数发现,emGA吸附MB为自发吸热过程,且吸附过程属于物理吸附。 相似文献
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沥青基球状活性炭对肌酐吸附行为研究 总被引:1,自引:0,他引:1
考察了具有不同BET比表面积及不同微孔含量的沥青基球状活性炭(PSAC)对肌酐的吸附行为。结果表明,随BET比表面积的增大,PSAC对肌酐的吸附容量及吸附速度明显增大;微孔含量越丰富.其对肌酐的吸附速度及容量越大;吸附动力学研究表明PSAC在水溶液中对肌酐的吸附符合单分子层Langmuir吸附模型。 相似文献
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利用热重技术考查八种不同煤焦的燃烧反应性,研究了不同煤焦的燃烧反应性与其灰分碱指数、比表面积、微孔表面积、石墨化程度和化学吸附量等物理化学性质之间的关系.结果表明:不同煤焦的燃烧反应性随煤阶的升高而降低,影响煤焦燃烧反应性的因素由强到弱依次为化学吸附量、石墨化程度、比表面积、微孔表面积、灰分碱指数.其中,化学吸附量可用来表征活性位点的数量;灰分碱指数、比表面积以及微孔表面积越大,石墨化程度越低,煤焦的化学吸附量越大,燃烧反应性越好.不同煤种煤焦的燃烧反应性与化学吸附量之间的线性相关系数最高达0.94,这说明化学吸附量是影响煤焦燃烧反应性的决定性因素. 相似文献
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高温下钙基吸附剂吸附CO2的研究 总被引:2,自引:0,他引:2
CaO基吸附剂是一种理想的CO2高温吸附剂。利用热重分析仪研究了由不同前体制备的CaO高温下对CO2的吸附性能。利用吸附仪测定了各吸附剂的比表面积等参数。实验发现CaO的最佳吸附温度范围为700—750℃;由CaC2O4.H2O制得的CaC2O4-CaO具有良好的吸附性能,在实验条件下,其吸附量为理论吸附量的89.1%;在较宽的CO2体积分数范围内,CaC2O4-CaO始终保持很高的吸附性能;吸收速率的大小受吸附剂比表面积、孔体积、孔结构等参数的共同影响。高温下,CaO基吸附剂吸附CO2的微观机理有待进一步研究。 相似文献
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用共沉淀法制备了一系列Ce-Cu-Al-O复合金属氧化物吸附剂,用于低温下脱除CO2气体中的微量H2S。采用XRD、N2物理吸附、SEM及XPS等手段对脱硫前后的吸附剂结构进行表征。研究了Ce含量、煅烧温度、气体空速、杂质气体及吸附温度对吸附剂脱除H2S性能的影响。结果表明,Ce-Cu-Al-O系列吸附剂在40℃条件下可有效脱除CO2气体中的H2S,Ce含量为10%的吸附剂(10Ce-Cu-Al-O)具有最大H2S穿透吸附量,为94.1mg/g。研究发现,引入CeO2能有效改善CuO的分散性,提高吸附剂的比表面积和孔容。提高煅烧温度,较大空速均不利于吸附剂的脱硫效果;平衡气CO2会抑制H2S的吸附;吸附温度不高于100℃时,10Ce-Cu-Al-O的穿透吸附量随温度升高而增加且不会生成COS副产物。表征结果显示,硫化后吸附剂的组分团聚导致了比表面积和孔容降低。此外,失活后的脱硫剂可在100℃用空气再生。 相似文献
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实验室制备了无水硫铝酸钙(C4A2S)单矿物,采用紫外-可见吸收光谱法测定氨基磺酸盐高效减水剂(简称“AS减水剂”)在C4A3S单矿物及其混合料(C4A3S+Ca(OH):+CaSO4·2H2O)矿物颗粒表面的吸附量,对AS减水剂在水化体系矿物颗粒表面的吸附行为进行了研究。结果表明:C4A3S单矿物和水化混合料对As减水剂的吸附量随初始浓度的增大而增大;对As减水剂的吸附量与极限吸附量随水化时间的延长而增大;在相同吸附时间内,AS减水剂在C4A3S混合料水化体系的吸附量与极限吸附量大于在C4A3S单矿物水化体系的吸附量与极限吸附量。 相似文献
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Haobin Zhang Jie Sun Bin Kang Yuanjie Shu Xiaoyan Shu Yu Liu Xiaofeng Liu 《Propellants, Explosives, Pyrotechnics》2012,37(2):172-178
The spheroidizing of TATB (1,3,5‐triamino‐2,4,6‐trinitrobenzene) can help to control preferred orientation and anisotropic expansion of TATB based PBXs, as well as to improve crystal quality, desensitizing efficiency, packing density, and even explosive energy. In this paper, TATB crystals with different morphology were obtained by high temperature recrystallization from anti‐solvents. TATB was dispersed into DMSO and heated to dissolve. Water as an anti‐solvent was added to the solution with different conrol parameters. We designed additional experiments to study the particular influence of these parameters. It was shown that the crystal morphology is strongly affected by the stirring rate and the amount of water added. The recrystallized TATB samples have similar thermal stability as starting TATB, but higher densities and purities, which indicates that the quality of TATB crystals was improved. By slowly adding an appropriate amount of water and cooling, regular crystals of TATB were obtained, which proves that water is a good morphology modifier for TATB. 相似文献
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研究了PVP对C12NCl和AS两单纯以二者复配体系的表面张力和增溶DMAB的影响。结果表明:PVP对C12NCl的表面张力与增溶作用影响较弱,但明显降低AS的表面张力。并形成复合物,提高对DMAB的增溶量。当C12NCl/AS混合溶液中加入PVP后,可明显提高对DMAB的增溶能力。且在混合摩尔比为1:1时增溶量最大,PVP对混合溶液的表面张力曲线未出现双折点。 相似文献
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Batikan Koroglu Alan K. Burnham Imren Mashiana Ana Racoveanu Christopher Arose Jonathan C. Crowhurst John G. Reynolds 《Propellants, Explosives, Pyrotechnics》2024,49(2):e202300124
This experimental study investigated the effects of confinement, starting mass, and heating rate on TATB thermal decomposition and sublimation using a combined Thermo-Gravimetric Analyzer and Differential Scanning Calorimetry (TGA/DSC) instrument. The confinement of volatile products was varied using different pinhole sizes with TGA/DSC pans. The measurements showed the open pan experiments without lids/pinholes resulted in complete sublimation of TATB between 320 °C and 360 °C. The heat of sublimation was determined to be 176 kJ/mol (42 kcal /mol), consistent with literature data obtained from other experimental techniques. The use of pinholes suppressed the sublimation of TATB such that the decrease in pinhole size resulted in 1) an increase in the enthalpy of reaction and an increase in the amount of carbonaceous material remaining at the end of decomposition, and 2) convergence of the two peak temperatures corresponding to maximum heat flow and maximum weight loss. Also, a transition from a two-exotherm thermal decomposition behavior towards a single-exotherm occurred as the pinhole size was decreased for a given starting mass or as the starting mass was increased for a given pinhole size. These results indicate the kinetics of TATB sublimation, TATB thermal decomposition, and gas diffusion out of a TGA/DSC pan can all compete and result in significantly different enthalpies, amounts of remaining materials, and peak temperatures depending on the pinhole size and starting mass used in the measurements. The results also indicate precise control of process variables (pinhole size, starting mass, and heating rate) in TGA/DSC measurements is required for thermal safety assessment of explosives. 相似文献
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Zhijian Yang Jinshan Li Bing Huang Shijun Liu Zhong Huang Fude Nie 《Propellants, Explosives, Pyrotechnics》2014,39(1):51-58
The insensitive high explosive 1,3,5‐triamino‐2,4,6‐trinitrobenzene (TATB) was selected for coating and desensitization of hexanitrohexaazaisowurtzitane (CL‐20), another high explosive, after surface modification. About 2 wt‐% polymer binder was adopted in the preparation process to further maintain the coating strength and fill the voids among energetic particles. The structure, sensitivity, polymorph properties, and thermal behavior of CL‐20/TATB by coating and physical mixing were studied. Scanning electron microscopy (SEM) and X‐ray photoelectron spectroscopy (XPS) results indicate that submicrometer‐sized TATB was compactly coated onto the CL‐20 surface with coverage close to 100 %. The core‐shell structure of CL‐20/TATB was confirmed by observation of hollow TATB shell from the CL‐20 core dissolved sample. X‐ray diffraction (XRD) analysis revealed that the polymorph of CL‐20 maintained ε form during the whole preparing process. Thermal properties were studied by thermogravimetry (TG) and differential scanning calorimeter (DSC), showing effects of TATB coating on the polymorph thermal stability and exothermic decomposition of CL‐20. Both the impact and friction sensitivities were markedly reduced due to the cushioning and lubricating effects of TATB shell. The preparation of explosive composites with core‐shell structure provides an efficient route for the desensitization of high explosives, such as CL‐20 in this study. 相似文献
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Guangcheng Yang Fude Nie Hui Huang Lin Zhao Wanting Pang 《Propellants, Explosives, Pyrotechnics》2006,31(5):390-394
Nano‐TATB was prepared by solvent/nonsolvent recrystallization with concentrated sulfuric acid as solvent and water as nonsolvent. Transmission Electron Microscopy (TEM) and Atomic Force Microscopy (AFM) were used to characterize the appearance and the size of the particles. The results revealed that nano‐TATB particles have the shape of spheres or ellipsoids with a size of about 60 nm. Due to their small diameter and high surface energy, the particles tended to agglomerate. By using X‐ray powder diffraction (XRD), broadening of diffraction peaks and decreasing intensity were observed, when the particle sizes decreases to the nanometer size range. The corrected average particle size of nano‐TATB was estimated using the Scherrer equation and the size ranged from 27 nm to 41 nm. Furthermore, the specific surface area and pore diameter of nano‐TATB were determined by BET method. The values were 22 m2/g and 1.7 nm respectively. Thermogravimetric (TG) and Differential Scanning Calorimetric (DSC) curves revealed that thermal decomposition of nano‐TATB occurs in the range of 356.5 °C–376.5 °C and its weight loss takes place at about 230 °C. Furthermore, a slight increase in the weight loss was observed for nano‐TATB in comparison with micro‐TATB. 相似文献