钾明矾/膨胀石墨定形复合相变材料储热性能研究

选用十二水硫酸铝钾(钾明矾)为相变材料,采用化学改性后的膨胀石墨为支撑材料,利用"熔融共混-凝固定形"法制备了定型复合相变材料。通过扫描电子显微镜(SEM)、差示扫描量热分析仪(DSC)和热重分析仪(TGA)分别研究了样品的微观形貌、相变焓及其熔化过程。改性膨胀石墨质量分数为20%的样品能够均匀吸附大量相变材料。DSC分析结果表明,其熔点和熔融焓分别为84.39 ℃和473.52 kJ/kg。经过50次的充放热循环测试,改性膨胀石墨质量分数为20%的样品的熔融焓仅下降7.48%。改性膨胀石墨与钾明矾具有良好的相容性。充放热测试表明,该复合相变材料具有良好的循环稳定性,是一种性能优良的相变热储存材料,在建筑物节能领域和太阳能热利用中具有广阔的应用前景。     

黏土多孔材料负载纳米质子化氮化碳(g-C3N4)及其增强光催化性能研究

在蒙脱石的层间域插入季铵盐和正硅酸乙酯.通过水热控制和pH调节使正硅酸乙酯围绕季铵盐胶束水解形成二氧化硅.通过煅烧去除季铵盐胶束,形成蒙脱石多孔材料.将通过质子化和超声处理的纳米级石墨相氮化碳(g-C3N4)负载到多孔蒙脱石多孔材料孔道结构中.通过扫描电镜(SEM)表征了其表面形貌、颗粒大小和微观结构;利用物理氮气吸附-脱附表征其孔道结构;用傅里叶变换红外(FT-IR)表征了表面的官能团;通过X-射线衍射仪(XRD)分析其有序晶体结构和层状结构.通过对水相中罗丹明B的降解研究其光催化性能.实验结果表明,负载纳米级g-C3N4的蒙脱石多孔材料具有优异的光催化降解有机物的能力.     

PO4^3-／Al—MCM-41介孔分子筛合成及表征

通过液晶模板机理合成了Al-MCM-41介孔分子筛,并用磷酸浸渍法制备PO4^3-/Al—MCM-41。通过X射线衍射（XRD）、氮气吸附-脱附、红外光谱、Hammer指示剂胺滴定等方法对所合成样品进行了表征。XRD和N2吸附脱附研究结果表明,PO4^3-／Al-MCM-41有较规则的孔道结构。平均孔径3．10nm,比表面积为560m^2／g。酸量滴定分析表明,PO4^3-／Al-MCM-41具有较强的酸性。     

二氧化锰制备及催化燃烧甲苯性能研究

以高锰酸钾和富马酸为原料,采用溶胶凝胶法合成了二氧化锰（MnO₂）催化剂,通过X射线衍射分析（XRD）、扫描电镜（SEM）、N₂吸附-脱附以及氢气程序升温还原（H₂-TPR）等技术对制备材料的结构和还原性能进行了表征,并考察材料的焙烧温度对其催化燃烧甲苯性能的影响.结果表明,焙烧温度为450 ℃的产物为纯相的α-MnO₂,催化剂呈现颗粒状形貌并具有较大的比表面积（60.56 m²·g^-1）,低温下易还原,具有较好的甲苯催化燃烧性能,完全燃烧温度T₉₉为210 ℃.     

SAPO-34动态脱附特性实验研究

针对吸附材料在太阳能吸附式制冷系统中的应用,利用称重法在高温真空环境下对水的脱附性能进行了实验研究,探究不同温度、压力对SAPO-34沸石分子筛脱附性能的影响.结果表明:温度对材料脱附性能的影响要远大于压力的影响,这在吸附式制冷系统中是非常有利的;当压力一定时,材料的脱附完善度随温度的升高而增大,且不随温度变化均匀分布.温度过高会影响SAPO-34的性能及影响材料的使用寿命;当温度一定时,材料的脱附完善度随着压力的降低而增大,其变化随压力变化分布得较为均匀.     

太阳能沸石储热技术的实验研究

为了探索利用太阳能进行储热和供暖的可能性,建立了一套开式循环太阳能储热装置,开展太阳能热 利用的实验研究.实验采用天然沸石作为吸附剂,水作为吸附质,沸石床集储热和供热于一体.为了尽可能接近 实际应用情况,实验过程全部在冬天寒冷环境下完成.在对冬天太阳辐射能观测的基础上.详细测量了天然沸 石床的吸附／脱附的动态特性,对冬天正常日照条件下沸石储热床的吸附／脱附过程的可利用热能进行计算;进 而对整个太阳能储热装置的热效率进行分析,为太阳能用于供暖提供基本依据.根据计算,装置的吸附热约为 152.5 kJ,脱附热为2 126 kJ,太阳能储热装置的总的热利用效率超过30％.     

温敏型调湿材料的制备与表征

分别以甲基纤维素、异丙基丙烯酰胺、甲基丙烯酸及丙烯酰胺温敏材料聚合反应得不同种类的温敏型调湿材料,并分别通过间歇式吸附/脱附实验、TG-DTA和FTIR分别表征几种温敏型调湿材料的吸放湿动力学实验、热稳定性及其结构,讨论了不同聚合体温敏性对复合材料吸放湿性能的影响.结果表明:脱附速率随3种温敏材料的低临界溶解温度的降低而增加,异丙基丙烯酰胺与甲基纤维素的共聚物的放湿速率最快,80℃条件下10 min可以脱附95%以上;耐盐性较好的甲基纤维素与CaCl2复合制备有机-无机温敏相变材料具有较高的吸湿性能,RH=100%时的吸湿量可以达到1.45 g/g,且所有材料在350℃以下具有良好的热稳定性.     

贯通大孔SnO2纳米材料的制备及气敏性能研究

为改善二氧化锡（SnO₂）的气敏性能,以聚苯乙烯（PS）微球为模板,SnO₂纳米晶为骨架,采用颗粒模板法成功制备大孔SnO₂（MP-SnO₂）气敏材料,并对制备的样品进行差热分析（TGDTA）、X射线衍射（XRD）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）和氮气吸附脱附分析。结果表明,制备的MP-SnO₂样品具有贯通孔道大孔结构,平均大孔孔径为300 nm,与SnO₂纳米晶相比具有更大的比表面积。通过气敏测试发现MP-SnO₂在280℃工作温度下对体积分数4×10-4的乙醇气体的灵敏度高达138,是SnO₂纳米颗粒的1.6倍,显示出更加优异的气敏性能。     

不同孔径介孔碳的合成及对药物的缓释性能研究

采用模板法合成2种孔径不同的介孔碳分子筛CMK-3和CMK-1,介孔碳分别负载难溶性药物布洛芬.对负载药物布洛芬的介孔碳分子筛利用X射线衍射(XRD)、氮气吸附-脱附分析、扫描电镜分析(SEM)、透射电镜分析(TEM)、IR等表征手段分析,结果表明药物分子确实存在于分子筛孔道中.同时研究分子筛对布洛芬的缓释作用,比较孔道大小对药物缓释性能的影响.     

镍铝复合介孔氧化物的合成和表征

以阴离子表面活性剂为模板剂,硝酸铝为铝源,氯化镍为镍源,水热超声法合成镍铝复合介孔氧化物。当n（Ni）/n（Al）=1∶7,反应温度80℃,反应时间28 h,晶化12 h,样品有较规则的介孔结构。用X射线多晶衍射（XRD）、红外光谱（IR）、N2吸附-脱附、NH3和CO2程序升温脱附（NH3-TPD和CO2-TPD）、程序升温氧化还原（TPO和TPR）等方法对样品进行了表征。结果表明,样品具有典型的介孔结构特征,孔径分布较窄,平均孔径2.6 nm,孔容积0.216 cm^3/g,比表面积为297.132^3/g。样品具有弱和强的酸碱中心,340℃可被氧化,430℃可被还原。     

Dynamic Adsorption of Toluene on Hierarchical Porous Carbons with Varying Pore Structure

Hierarchical porous carbon material (MMC) was successfully fabricated via hard template synthesis method by carbonization of furfury alcohol within the template (MCM-41).The prepared MMC was studied with characterization methods including scanning electron microscopy (SEM),transmission electron microscopy (TEM),nitrogen adsorption-desorption analyses,and infrared spectral analysis (FTIR).To investigate kinetics of toluene adsorption of hierarchical porous carbon materials,the adsorption performances of these carbon samples with varying pore structure (MC-1,MMC,MMHPC) were analyzed via dynamic adsorption.And the Langmuir model and Freundlich equation were employed to correspond with adsorption isotherms to study the adsorption mechanism.The experimental results demonstrate that the Langmuir model is more appropriate to describe the adsorption process.The capacities of toluene adsorption follow the order of MMC MMHPC (micro-meso hierarchical porous carbon) MC-1(microporous carbon).MC-1 has satisfactory absorption performance due to its large pore volume and high ratio of micropores.MMHPC has excellent toluene adsorption performance for proper amounts of surface oxygen containing groups.Long saturation time,interconnected hierarchical pore channels,and large specific surface area make MMC also a promising material for VOCs treatment.These data reveal that the pore channel structure,rational pore distribution,high surface area and reasonable amounts of surface oxygen groups are the main factors contributed to excellent toluene adsorption performance,which proposes theoretical basis for hierarchical porous carbon materials to further engineering application.     

具有大孔-介孔结构的磷酸钛的合成及溶菌酶吸附

以混合表面活性剂十六烷基三甲基溴化铵(CTAB)和烷基酚聚氧乙烯醚(OP-10)合成了大孔-介孔结构磷酸钛,并利用X射线衍射、红外光谱、扫描电镜、透射电镜、氮气吸附等表征手段对所制备材料的结构、形貌进行表征.水/乙醇体系的样品具有大孔-介孔结构,比表面积为162 m2/g,且大孔-孔径为1~2 m.乙醇溶剂条件下样品以介孔结构存在,比表面积可以达到272 m2/g,孔容0.359 cm3/g,孔径3.7 nm.在不同的pH溶液中测试溶菌酶吸附性能,最大吸附量在等电点处(=25.94 mol/g),吸附等温线为典型的L型,表明磷酸钛是一种很好的蛋白质吸附剂.     

超细羽绒粒子对三种不同染料吸附动力学研究

采用超细粉体加工技术制备了超细羽绒粒子,并对其粒径、孔结构等进行了表征。将制备的超细羽绒粒子应用于染料废水的处理,研究其对模拟染料废水溶液中酸性大红3R、直接耐酸大红4BS、还原大红R的吸附性能。结果表明：超细羽绒粒子的平均粒径是2．34±0．26um,且具有良好的孔结构,其中以大孔为主,而且孔径分布较宽。动力学研究结构表明伪二级动力学方程可更好地描述超细羽绒粒子对酸性大红3R、直接耐酸大红4BS、还原大红R染料的吸附行为。     

分离膜孔结构的电化学交流阻抗谱表征

利用电化学工作站的电化学交流阻抗谱构建一种测量分离膜通孔结构的电化学表征技术. 通过改变聚乙烯吡咯烷酮的质量分数,制备具有不同孔洞结构的聚砜分离膜. 采用电化学工作站、孔容积分析仪、膜性能测试装置对分离膜的孔结构和水通量进行分析. 结果表明:随着聚乙烯吡咯烷酮质量分数的增加,分离膜的通孔电阻下降,孔径增大,水通量增加. 在孔径为10 nm~40 nm的范围内,分离膜的水通量结果与其通孔电阻之间成反比关系,该关系符合分离膜的孔洞模型. 因此,电化学交流阻抗谱是一种评价分离膜的通孔结构的有效方法.     

Low-cost preparation of mesoporous silica with high pore volume

Mesoporous silica materials with high pore volume were successfully prepared by the chemical precipitation method, with water glass and a biodegradable nonionic surfactant polyethylene glycol （PEG）. The obtained materials were characterized by transmission electron microscopy （TEM）, scanning electron microscopy （SEM）, thermo gravimetric analyzer and differential scanning calorimetry （TG-DSC）, nitrogen adsorption-desorption measurements, and X-ray diffraction （XRD）. The results showed that the changes of the pore parameters depended on both the surfactant content and heat treatment temperature. When the content of PEG was 10wt% and the obtained PEG/SiO2 composite was heated at 600℃, the mesoporous silica with a pore volume of 2.2 cma/g, a BET specific surface area of 361.55 m^2/g, and a diameter of 2-4 μm could be obtained. The obtained mesoporous silica materials have potential applications in the fields of paint and plastic, as thickening, reinforcing, and flatting agents.     

Effects of coal rank,Fe304 amounts and activation temperature on the preparation and characteristics of magnetic activated carbon

Coal-based Magnetic Activated Carbons(CMAC's)were prepared from three representative coal samples of various ranks:Baorigele lignite from Inner Mongolia; Datong bitumite from Shanxi province; and Taixi anthracite from Ningxia Hui Autonomous Region.Fe3O4 was used as a magnetic additive.A nitrogen-adsorption analyzer was used to determine the specific surface area and pore structure of the resulting activated carbons.The adsorption capacity was assessed by the adsorption of iodine and methylene blue.X-ray diffraction was used to measure the evolution behavior of Fe3O4 during the preparation process.Magnetic properties were characterized with a vibrating-sample magnetometer.The effect of the activation temperature on the performance of CMAC's was also studied.The results show that,compared to Baorigele lignite and Talxi anthracite,the Datong bitumite is more appropriate for the preparation of CMAC's with a high specific surface area,an advanced pore structure and suitable magnetic properties.Fe3O4 can effectively enhance the magnetic properties and control the pore structure by increasing the ratio of mesopores.An addition of 6.0% Fe3O4 and an activation temperature of 880 ℃ produced a CMAC having a specific surface area,an and 4.623 emu/g,respectively.The coal used to prepare this specimen was Datong bitumite.     

硅胶孔径对吸附剂吸湿性能及制冷特性的影响

为开发出一种适用于吸附制冷的高性能吸附剂,选择了3种不同孔径的商用硅胶,孔径分别是2～3、4～7、8～10 nm,利用浸泡的方法将氯化钙嵌入硅胶微孔内来制备复合吸附剂,并对吸附剂的吸附性能进行了实验测试.测试结果表明:对于2～3 nm的硅胶,由于孔径较小,氯化钙的浸入堵塞或者部分堵塞了水进入硅胶的传质通道,导致复合吸附剂不论是吸附量还是吸附速率与纯硅胶相比都没有提高;而对于4 ～7 nm和8～ 10 nm的硅胶,其复合吸附剂不论是吸附量还是吸附速率都较其相应的纯硅胶有大幅提高.复合吸附剂在20％湿度下吸附20 min和2h的吸附量分别是8.08 g/100 g和15.7 g/100 g,在同等工况下,纯硅胶的吸附量分别是1.96 g/100 g和2.0 g/100 g.用制备的复合吸附剂制作了一台小型吸附制冷机并进行了测试,当热源温度为90℃,冷却水温度为35℃时,在整个循环周期内(15 min),制冷功率为1.03 kW,单位质量吸附剂的制冷功率(SCP)为128.3 W/kg,性能系数(COP)为0.27.     

ZS-5／MCM-41复合分子筛用于FCC汽油脱硫的初步考察

采用纳米组装法制备ZSM-5／MCM-41复合分子筛,应用XRD、N2吸附-脱附,NH3-TPD、SEM等方法对ZSM5／MCM-41的性质进行了表征,考察了金属CuO负载含量、吸附温度、重时空速等因素对复合分子筛的脱硫性能的影响。结果表明,分子筛的孔容、孔径、比表面积、酸性等性质均能影响吸附剂的脱硫性能,在常压且较低的温度下,质量分数5％CuO负载催化剂经活化后的脱硫率近90％。ZSM-5／MCM-41在吸附脱硫的同时,对FCC汽油中烯烃和芳烃组分的含量分布具有-定的影响。     

黄土高填方场地孔隙水压力的变化规律

孔隙水压力是评价黄土高填方场地变形与稳定的重要参数。为探讨沟谷地形中黄土高填方场地孔隙水压力增长和消散规律，对陕北某黄土高填方工程进行了施工期和工后期的孔隙水压力监测和分析。结果表明：在分析超静孔隙水压力的增长和消散规律时，须扣除因土层压缩和地下水位变化而引起的静水压力变化值；孔隙水压力的增长和消散主要受地下水位和填土荷载的影响；土方填筑快，孔隙水压力增长快，反之，孔隙水压力增长慢，甚至消散；施工期的孔隙水压力增量与填土荷载增量呈近似线性关系，多级荷载的孔隙水压力系数小于0.2，土体始终处于稳定状态；工后期孔隙水压力消散缓慢，沉降达到完全稳定需要较长时间。     

Synthesis,structural characterization and hydrogen storage of nickel-containing mesoporous MCM-48 by electroless plating

Hydrogen is a promising fuel for it is clean, highly abundant and non-toxic, but on-board storage of hydrogen is still a challenge. So it is imperative to have an efficient method of hydrogen storage. The mesoporous MCM-48 especially the nickel-containing MCM-48 has great potential in hydrogen storage. MCM- 48 was prepared by hydrothermal synthesis. Then electroless plating technology was used to deposit Ni on the surface of MCM-48 under ultrasonic environment. Powder X-ray diffraction (XRD), transmission electron microscopy (TEM), and N₂ adsorption-desorption were employed to investigate the pore structure properties. The results showed that all the samples had Ia3d cubic structure and pore channels were highly ordered. Hydrogen adsorption studies showed that the MCM-48 after nickel plating adsorbed nearly twice the amount of hydrogen than pure MCM-48 at 2.0 MPa, 263 K. So we believe that a small amount of Ni can improve the capacity of hydrogen adsorption of MCM-48 efficiently.