煤矸石制备活性炭-沸石复合材料的研究

研究了由煤矸石制备活性炭-沸石分子筛复合材料的方法.首先在高温氮气气氛中活化由K2CO3浸渍过的煤矸石,使其中的碳质转化为活性炭,然后将其置于NaOH溶液中,使其中的硅铝氧化物晶化为沸石分子筛.讨论了活化和晶化两过程中各种条件对材料合成的影响,并用XRD和N2吸附对该复合材料进行了表征,对水和正己烷的吸附性能进行了测试.结果表明,该复合材料不仅具有微孔和中孔的复合孔结构特征,而且具有亲水和亲油的吸附特征.     

AC/X-G吸附剂的制备及CH_4/N_2吸附分离性能

采用浓度为0.2 g·ml~(-1)的葡萄糖溶液对13X沸石/活性炭复合材料(AC/X)进行碳沉积,研究沉积次数对复合吸附剂(AC/X-G)孔结构、表面性质和CH_4/N_2吸附分离性能的影响。通过X射线衍射,77 K下的N2吸附/脱附,扫描电镜,CO_2-TPD以及红外光谱表征样品的晶型、孔结构和表面性质,在298 K、100 k Pa下对其CH_4和N_2吸附等温线进行测定,并将吸附结果与文献中碳材料和13X沸石的吸附性能进行比较。结果表明:随着沉积次数的增加,AC/X-G吸附剂中X型沸石的相对含量降低,微孔比表面积和微孔体积减少。AC/X-G的表面被碳膜覆盖,碱量降低,但出现强碱位和含氧基团C—O键。AC/X-G的CH_4和N_2吸附量下降,但吸附分离系数提高,沉积3次的样品AC/X-G-3的CH_4/N_2吸附分离系数达到3.0,表面的含氧基团有利于提高复合材料的CH_4/N_2吸附分离性能。     

碱性蛋白酶在空气/水和正己烷/水界面的吸附及扩张流变的研究

本文运用界面张力、界面流变及动态光散射等方法对碱性蛋白酶在空气/水和正己烷/水界面的界面行为进行了研究。另外,还运用Isofit软件对碱性蛋白酶在界面的平衡界面张力用不同的吸附模型进行了拟合。研究结果显示:碱性蛋白酶在正己烷/水界面的界面张力和界面模量要比其在空气/水界面的界面张力和界面模量都要小;碱性蛋白酶分子在正己烷/水界面上的排列较其在空气/水界面的排列紧密;碱性蛋白酶分子在正己烷/水界面上的相互作用较其在空气/水界面的大,碱性蛋白酶在正己烷/水界面形成的界面膜的弹性更大;单个碱性蛋白酶分子在正己烷/水界面所占的摩尔面积比其在空气/水界面所占的摩尔面积小。基于对碱性蛋白酶在正己烷/水和空气/水界面的吸附和界面流变的分析,我们提出了碱性蛋白酶在正己烷/水和空气/水界面的分子构象。     

13X分子筛静态脱除含硫模型化合物的吸附研究

采用噻吩/正己烷配制出含硫模型化合物,以13X分子筛为吸附剂,在常压条件下,用静态吸附法评测了吸附时间、吸附温度、含硫模型化合物浓度等吸附条件对吸附剂脱硫性能的影响。实验结果表明:13X型分子筛在6 h时吸附基本达到饱和,并对其吸附动力学、热力学及吸附等温曲线的研究,发现此吸附反应为放热反应,并求出吸附焓变及熵变,确定吸附反应为二级反应。     

正己烷在5A分子筛上高温吸附/脱附及扩散性能

采用智能质量分析仪IGA,在较高温度(150—300℃)下,测定5A分子筛对正己烷的吸附/脱附等温线,考察吸附温度对吸附等温线的影响,研究改性5A分子筛的二次孔结构与正己烷吸附/脱附及扩散性能的关系。结果表明:5A分子筛对正己烷的吸附等温线随着吸附温度的升高优惠程度逐渐降低,在300℃下,5A分子筛对正己烷吸附等温线接近线性,压力从14 kPa降至1.4 kPa,被5A分子筛吸附的正己烷可脱附出45.95%;在200℃下,改性5A分子筛(5A-11)对正己烷的脱附质量比是未改性(5A-1)的3.5倍;正己烷在5A-11分子筛上的脱附扩散系数为8×10-13m2/s,约是未改性的20倍;5A-11分子筛拥有较小的二次孔孔径和较为合理的大孔分布,使其对正己烷有着良好的脱附性能。     

AC/X-G吸附剂的制备及CH4/N2吸附分离性能

采用浓度为0.2g·ml^-1的葡萄糖溶液对13X沸石/活性炭复合材料(AC/X)进行碳沉积,研究沉积次数对复合吸附剂(AC/X-G)孔结构、表面性质和CH₄/N₂吸附分离性能的影响。通过X射线衍射,77K下的N₂吸附/脱附,扫描电镜,CO₂-TPD以及红外光谱表征样品的晶型、孔结构和表面性质,在298K、100kPa下对其CH₄和N₂吸附等温线进行测定,并将吸附结果与文献中碳材料和13X沸石的吸附性能进行比较。结果表明:随着沉积次数的增加,AC/X-G吸附剂中X型沸石的相对含量降低,微孔比表面积和微孔体积减少。AC/X-G的表面被碳膜覆盖,碱量降低,但出现强碱位和含氧基团C-O键。AC/X-G的CH₄和N₂吸附量下降,但吸附分离系数提高,沉积3次的样品AC/X-G-3的CH₄/N₂吸附分离系数达到3.0,表面的含氧基团有利于提高复合材料的CH₄/N₂吸附分离性能。     

介孔炭–HY分子筛复合型脱硫吸附剂的制备与性能

制备HY分子筛与介孔炭(OMC)的复合脱硫吸附剂,利用X射线衍射、氮气吸附脱附、Fourier变换红外光谱、NH3–程序温度脱附和透射电子显微镜对复合材料进行表征。结果表明:与OMC相比,OMC–HY复合脱硫吸附剂具有微–介孔的孔径分布,酸性提高,比表面积和孔容增加。OMC–HY吸附脱除二苯并噻吩的热力学和动力学研究表明,二苯并噻吩在OMC–HY上的吸附符合Langmuir吸附等温模型和二级动力学模型。     

锰氧化物修饰铁酸钴纳米棒对亚甲基蓝的吸附性能

利用铁酸钴纳米纤维优良的磁性和锰氧化物优异的吸附性能,以介孔铁酸钴纤维为载体,在其表面负载纳米二氧化锰,制备了锰氧化物修饰铁酸钴纳米棒复合材料。通过X射线衍射、扫描电子显微镜、X射线能谱、Fourier红外光谱等测试手段对样品形貌和物相组成进行了表征。将所得样品用于去除模拟污染水体中的染料,考察了不同制备条件下所得产物对亚甲基蓝的吸附性能,探讨了吸附过程的热力学和动力学过程。结果表明:铁酸钴纳米纤维上负载锰氧化物复合材料对亚甲基蓝有优异的吸附能力,最大吸附容量可达99.60 mg/g。常温下,其吸附等温线可用Langmuir吸附模型描述,吸附动力学符合Lagergren二级速率方程,吸附为放热自发过程。     

聚噻吩/MCM-41的合成与表征

文章以FeCl3为氧化剂,采用原位化学聚合的方法制备了聚噻吩/MCM-41新型复合材料,并对其结构和性能进行了表征。结果表明:小角X射线衍射和氮气吸附与脱附说明复合材料具有规则的介孔结构并且孔径明显小于分子筛MCM-41的孔径,红外光谱分析进一步证明PT进入了MCM-41的介孔孔道内,热重分析表明,聚噻吩进入孔道之后热稳定性得到了提高。     

GO/介孔TiO_2复合材料的制备及性能研究

以硫酸钛为钛源、聚乙二醇为模板剂,采用水热法制备了一系列具有吸附及光催化双功能的GO(氧化石墨烯)/介孔TiO_2复合材料,采用XRD、TEM、BET和紫外-可见漫反射等测试手段对所制备系列样品的微观结构、孔结构和光谱学性能进行了初步表征,并以甲基橙溶液为目标污染物测试其吸附性能及光催化活性,进而探讨了GO/介孔TiO_2复合材料的最佳制备条件。结果表明,GO/介孔TiO_2复合材料中氧化钛均为锐钛矿相,晶粒尺寸均在7 nm左右,系列复合材料均属于Langmuir Ⅳ型介孔结构,GO的复合适当拓宽体系光响应范围;水热温度为110℃、水热时间为24 h、GO的复合比为5 wt%时,对甲基橙溶液的吸附及光催化活性最强,1 h内降解率可达100%。     

A novel double-function porous material: zeolite-activated carbon extrudates from elutrilithe

Zeolite-activated carbon (ZEOAC) extrudates were synthesized from natural elutrilithe through a two-step process consisting of the chemical activation of elutrilithe with K₂CO₃ at 800°C followed the hydrothermal transformation in NaOH solution. During the chemical activation, carbon in elutrilithe was activated, and the kaliophilite crystalline phase with framework structure of linked (Si, Al)O₄ tetrahedra was formed simultaneously, which was then converted into zeolite A in alkaline medium. The as-synthesized samples were characterized by thermal gravimetric and differential thermal analyses (TG/DTA), N₂ adsorption, X-ray diffraction (XRD), scanning electron microscopy (SEM) and adsorptive capacities for water and hexane. The results show that this new material ZEOAC possesses the typical characteristics of zeolite and activated carbon, micro- and mesoporous structure, hydrophilic and hydrophobic properties.     

Synthesis of ordered carbon replicas by using Y-zeolite as template in a batch reactor

Ordered carbon material that preserves the structural regularity of the parent zeolite template was synthesized by using ethylene as carbon source and HY-zeolite in a batch reactor. The obtained carbons exhibit a high degree of microporosity having BET surface areas between 1400 and 2400 m²/g. The morphology and structure of the prepared carbon materials were investigated by elemental analysis, X-ray diffraction measurements, scanning electron microscopy and nitrogen adsorption. The results were compared with the parent zeolite template. The carbonization procedure of precursor-encapsulated samples was investigated by thermal analysis and it has been found that the resulting quality of the ordered carbons strongly depends on the heat treatment of the composite material.     

Synthesis and catalytic performance of a bi-phase core-shell zeolite composite

A zeolite composite Y/Beta with core-shell structure was synthesized by adding tetraethylammonium bromide (TEABr) exchanged NaY zeolite into the pre-reacted mixture used to prepare Beta zeolite. The composite was characterized by XRD, N₂ adsorption, SEM, and FTIR spectra of pyridine. The results show that the composite is composed of a core zeolite Y and a shell of intergrown zeolite Beta crystals, representing dual microporous structures of both Y and Beta zeolites and a new mesoporous structure. The composite has a high activity in n-octane catalytic cracking because of the formation of intergrowths and the change of acidity due to the distorted interface and surface defects.     

Preparation of Na‐P1‐Type Zeolite and its Composite Material with Nanosized Magnetite

The Na‐P1‐type zeolite having a high cation‐exchange capacity (CEC) was obtained using the waste coal fly ash from thermal power stations and a 2M NaOH solution at 100°C. The Na‐P1‐type zeolite was formed with the reaction time of 6 h at 100°C, and its CEC value increased with an increase in the reaction time. The addition of a suitable amount of NaAlO₂ to the fly ash was also effective for improving the CEC value. A new composite material consisting of the Na‐P1‐type zeolite and magnetite was synthesized from the fly ash and iron chlorides because the magnetic collection was possible using this composite material after radioactive Cs⁺ ion adsorption. The existence of nanosized magnetites in the polycrystalline zeolite (several micrometers) was confirmed by TEM observations. The CEC and magnetic property of these composite materials were characterized.     

磁性X沸石的合成及其性能

采用水热合成法,在X型沸石的晶化原料液中加入磁核合成了磁性沸石,对合成产物进行了结构性能测试. 结果表明,产物为X型沸石结构,具有较好的磁性能和吸附性能. 饱和磁化强度为3.7 emu/g,在磁场作用下,磁性沸石在30 min内完成与母液的分离,产物的比表面积为571.5 m2/g,铅离子吸附量为196.8 mg/g.     

水中Ni~(2+)在粒状沸石/活性炭复合材料上的吸附研究

采用廉价的煤矸石为主要原料,添加一定量的沥青粉制备了沸石NaA/活性炭粒状复合材料,并以此作为吸附剂,研究了水溶液中Ni~(2+)在该复合材料中的吸附行为,考察溶液的初始浓度、吸附时间和pH对吸附的影响.结果表明溶液较高的pH值有利于Ni~(2+)在吸附剂上的吸附;随Ni~(2+)初始浓度的增大复合材料的吸附量增大,而Ni~(2+)的去除率随之减小;Ni~(2+)在复合材料上的吸附接近Langmuir-Freundlich等温吸附模型,反映了吸附表面的多相性及两类吸附中心在复合材料上的共存性;吸附速率遵循准二级吸附动力学模型.     

改性沸石/EPDM复合材料对水中六价铬离子的吸附研究

以三元乙丙橡胶(EPDM)作为基体,酸改性沸石粉作为填料,利用熔融共混的方法,制备出一种可以吸附水中六价铬离子的复合材料。通过对比天然沸石、酸改性沸石和改性沸石/EPDM复合材料三者对水中六价铬离子的平衡吸附量,得出复合材料的吸附量要远远大于前两者。通过对复合材料吸附水中六价铬离子的过程进行Freundlich等温式的线性回归分析和数据拟合,确定该吸附过程符合Freundlich等温模式,并判断复合材料对水中六价铬离子是易于吸附的。     

SYNTHESIS OF WELL-CRYSTALLIZED ZEOLITE BETA AT LARGE SCALE AND ITS INCORPORATION INTO POLYSULFONE MATRIX FOR GAS SEPARATION

Using a silica source with high specific surface area, aluminum zeolite beta was successfully synthesized in a very short crystallization period through the conventional hydrothermal route. The obtained materials were characterized by means of XRD, TEM, FESEM, EDS, TGA/DTG, and N₂ adsorption/desorption techniques. It is found that the well-crystallized zeolite beta can be rapidly synthesized at 170°C in 9 h and the highly porous silica source used could be completely converted into zeolite beta. No difference results from the silica source used. Moreover, through this synthesis route, it is also possible to conveniently obtain zeolite beta at high yield for manufacturing composite membranes for gas separations. The gas permeation tests show that the incorporation of porous zeolite beta into a polymer has modified the gas permeation properties significantly, indicating industrial application potential of this new type of composite material.     

Synthesis, characterization, and catalytic properties of a hydrothermally stable Beta/MCM-41 composite from well-crystallized zeolite Beta

A Beta/MCM-41 composite has been synthesized with a new method by using well-crystallized zeolite Beta as silica and aluminum source. The prepared composite was characterized by XRD, FTIR, N₂ adsorption/desorption at 77 K, FE-SEM, DTG, ²⁹Si MAS NMR spectral techniques. It was shown that the composite consisted of a highly ordered mesoporous MCM-41 phase and a zeolite Beta phase. Its hexagonal mesoporous structure was still retained after statically treated for 120 h in boiling water. In contrast, the structure of generally synthesized Al-MCM-41 nearly completely collapsed. This might be attributed to the assembly of the dissolved fragments such as the first and/or secondary structural units of zeolite Beta into the mesoporous structure around surfactant micelles. This is supported by the catalytic result that the prepared composite showed higher activity and selectivity for medium fraction in hydrocracking of Daqing vacuum residue than the parent zeolite Beta, the Al-MCM-41 as well as the mechanical mixture of these two materials.     

Assessment of high performance SAPO-34/S-PEEK composite coatings for adsorption heat pumps

In this work, a new composite adsorbent coating on aluminum support, based on SAPO34 zeolite filler embedded into sulfonate polyether ether ketone matrix is investigated for adsorption heat pumps (AHP) applications. Composite zeolite/polymer mixtures, with 80–95 wt% content of SAPO-34 zeolite filler have been prepared and coated on aluminum substrates. The as prepared coatings showed a pull-off adhesion strength up to 2.0 MPa, significantly higher than conventional values of composite zeolite coatings reported in the literature. Scanning electron microscopy analysis demonstrated that the coating has a homogeneous morphology with zeolite filler well interconnected in the composite coating structure. Water adsorption isobars were carried out at equilibrium in the temperature range 30–120°C. The best adsorption performances for AHPs applications were observed for the PZ-95 batch, where a maximum water uptake of ∼29.0 wt% was reached, highlighting that the polymer matrix presence does not alter the zeolite adsorption capability (31.3 wt%).