不同工艺制备硫酸钾插层膨润土缓释性能研究

研究比较了由不同工艺制备硫酸钾并于膨润土层间插层、结晶、缓释。结果表明,碳酸钾制硫酸钾最佳工艺为:温度80℃,搅拌速度为1.5 m/s,搅拌时间30 min,矿浆浓度为20 g/100 mL;硫酸铵制硫酸钾最佳工艺条件为:配料比1.1∶1(摩尔比)、搅拌速度2.0 m/s,搅拌时间80 min,矿浆浓度25 g,乙醇浓度40%。     

CPAM插层膨润土复合材料的制备及对磷吸附行为

分别采用十六烷基三甲基溴化铵(CTMAB)、阳离子聚丙烯酰胺(CPAM)两步湿法成功制备出CPAM插层钠基膨润土(Bent)复合材料(CTMAB/Bent和CPAM/Bent),利用XRD、FESEM、FTIR、BET以及TG-DTG-DSC对材料进行了表征,并进行模拟含磷废水的吸附研究。结果表明:CPAM已稳定插层在Bent的片层结构中,其层间距显著增大,红外光谱出现明显的羰基吸收峰,比表面积减小而表面疏水性增强。含磷废水处理结果表明,吸附性能大小的顺序为CPAM/Bent> CTMAB/Bent> Bent,随着反应温度升高、含磷废水初始浓度增加以及pH降低,CPAM/Bent对磷的去除率逐渐增大,当含磷废水初始质量浓度为3.5 mg/L、pH≈5、温度为35℃、投加量5 g/L,20 min去除率达75%。CPAM/Bent经过5次吸附和再生后,其吸附磷的能力显著下降。吸附等温线均符合Langmuir和Freundlich方程,吸附过程更好地满足准二级动力学方程。     

插层膨润土复合材料制备及应用的研究进展

介绍了膨润土经插层后形成复合材料的制备方法,并结合膨润土的结构特征,对插层复合机理的热力学和动力学进行了分析.最后对插层膨润土复合材料的应用前景作了展望.     

膨润土颗粒的制备及对废水吸附性能研究

本文以哈密膨润土为研究对象,将钢渣、聚乙烯醇和淀粉按比例混合成型处理,对钢渣、膨润土量、焙烧温度、时间进行了考察。用静态吸附法评价成型膨润土颗粒对废水中Ni~(2+)去除效果及散失率,对最优的膨润土颗粒,研究吸附时间和颗粒投加量对Ni~(2+)去除率。结果表明:钢渣11%、膨润土量9 g、焙烧温度600℃、时间为1. 5 h时制备的膨润土颗粒吸附效果最佳,颗粒投加量1 g/50 m L,对模拟废水中Ni~(2+)去除率为63. 5%,成型造粒后的吸附效果要比直接使用效果好。     

阳离子聚丙烯酰胺复合插层有机膨润土的脱色性能

用阳离子聚丙烯酰胺（CPAM）分别插层改性钠基膨润土及十六烷基三甲基溴化铵（CTMAB）有机膨润土,分析了改性膨润土的结构,并研究了其对模拟及实际印染废水的脱色性能.结果表明,CPAM复合插层改性的CTMAB有机膨润土的层间距d001（20.480A）大于CTMAB有机膨润土（19.211A）、CPAM改性膨润土（13,604A）和钠基膨润土（13.270A）的层间距.用100mgCPAM复合插层改性膨润土处理200mL（30mg/L）活性艳红K-2G模拟染色废水时,脱色率达99%以上;处理实际印染废水时,脱色率可以达到94%,表现出优良的吸附、脱色、絮凝沉降的协同作用.     

有机改性膨润土对镉离子及苯酚的吸附性能研究

膨润土是一种广泛存在的自然资源,其价格低廉,比表面积大,具有良好的膨胀性、可塑性、粘结性和阳离子交换性能,是处理废水的理想材料。实验用十六烷基三甲基溴化铵(CTAB)、聚丙烯酰胺对膨润土进行复合改性,并研究其对镉离子和苯酚的吸附作用。结果表明,有机改性膨润土对镉离子的吸附率可达97%以上,对苯酚的吸附率可达76%以上。     

膨润土有机改性及吸附性能研究

结合天然膨润土的层状结构以及阳离子型表面活性剂的正电性和疏水性,以十六烷基三甲基溴化铵(CTMAB)为改性剂,制得有机阳离子改性膨润土。研究了有机改性膨润土投加量、p H值、吸附时间及吸附温度对甲基橙模拟废水脱色率的影响。试验结果表明:有机改性膨润土的投加量为4 g/L,吸附时间为40 min,废水p H值为6.0,吸附温度为35℃时,有机改性膨润土对甲基橙模拟废水的脱色率可以达到98.1%。     

微波法制备的有机膨润土及吸附性能研究

研究了利用微波制备双阳型有机膨润土的适宜条件,对微波法制备有机膨润土的机理进行了分析,并与常规法合成的有机膨润土在结构与吸附性能方面进行了对比。结果表明,微波法制备双阳型有机膨润土的适宜条件为两种阳离子型表面活性剂总用量为100CEC,微波辐照能量210J/mL。与常规湿法的相比,有机膨润土的层间距、有机碳含量有所提高,对染料的去除率有较大提高。     

氧化石墨烯插层膨润土复合材料高效吸附碱性紫3染料

通过超声途径,利用氧化石墨烯（GO）插层膨润土（Bent）制备复合材料（BGO）,并评估对碱性紫3的吸附效果。采用XRD、FTIR、BET、SEM、XPS等检测手段表征了复合材料的结构特征,通过Langmuir、Freundlich模型和伪一级、伪二级模型拟合了等温吸附数据和动力学吸附数据,范特霍夫方程研究热力学过程。结果表明：GO成功插入Bent层间,XRD图谱显示膨润土层间距从1.35nm（Bent）扩大至1.6nm（BGO）,BGO比表面积有大幅提升;吸附数据符合Langmuir等温线模型和伪二级动力学模型,在30℃、250mg/L初始浓度下,BGO最高吸附容量可达420.17mg/g,与Bent相比,BGO显示更强的吸附能力,吸附过程展现快速动态;热力学研究表明吸附过程是自发且吸热的。机理分析表明,高比表面积GO及所带含氧基团与Bent之间的协同作用共同决定BGO具有高吸附能力。     

插层法制备环氧树脂/膨润土纳米复合材料的研究现状

介绍了膨润土的结构特性、有机膨润土的制备，并对环氧树脂／膨润土纳米复合材料的制备方法及影响插层的因素进行了综述。     

Adsorption properties of tetradecyl- and hexadecyl trimethylammonium bentonites

This study concerns the adsorption properties of organo-bentonites obtained through the modification performed at 25%, 50% and 100% of the cation exchange capacity (CEC) using tetradecyl trimethylammonium bromide (TDTAB) and hexadecyl trimethylammonium bromide (HDTAB). According to the XRD measurements, TDTAB and HDTAB form bilayers between the silicate layers when the montmorillonite surface is modified by 100% CEC. At 25% and 50% CEC, a random interstratification of monolayer and bilayer structures is observed. The surface area of bentonite decreases upon modification. The adsorption properties of organo-bentonites were tested using phenol as a model pollutant. Batch kinetic and isotherm studies were conducted over the concentration range from 50 to 1000 ppm at pH of 5.5. The adsorption excess isotherms of bentonites show different regions. A considerable increase was observed in the adsorption efficiency of montmorillonite modified with HDTAB at 100% CEC.     

壳聚糖及其衍生物对金属离子吸附研究进展

壳聚糖是一种天然高分子,分子中含有大量的氨基和羟基,对金属离子有很好的吸附能力.本文综述了壳聚糖及其衍生物对金属离子的吸附研究情况,并对其发展前景作了展望.     

Comparison of solution intercalation and melt intercalation of polymer-clay nanocomposites

Polymer-clay nanocomposites of poly(ethylene oxide)/Na-montmorillonite (PEO/MMT) and PEO/organo-modified bentonite (B34) systems prepared via solution intercalation and melt intercalation have been compared by X-ray diffraction and Fourier transform infrared (FTIR) analysis. The gallery size of solution-intercalated hybrids in both PEO/MMT and PEO/B34 systems increases with PEO content up to a plateau level at 15%. However, the gallery size of melt-intercalated PEO/MMT and PEO/B34 hybrid remains the same regardless of the PEO concentration. FTIR analysis shows no difference in spectrum of samples prepared by solution intercalation compared to melt intercalation. The PEO conformation in the PEO/clay intercalated hybrids is concluded to be a distorted helical structure.     

改性纤维素材料对金属离子吸附研究进展

纤维素在地球上含量十分丰富,且表面含有大量的羟基,可以通过羟基一系列的衍生反应,对纤维素进行改性,将纤维素制成离子型的吸附剂。本文就纤维素改性,综述了近些年来国内外以纤维素为原料改性制得的吸附剂相关的研究进展。     

高岭石/丙烯酰胺插层复合物的微波制备及其表征

高岭石及其有机插层复合物在高性能陶瓷领域有着良好的应用前景。本文利用微波技术,以DMSO作为前驱体,制备高岭石/丙烯酰胺插层复合物,发现微波对丙稀酰胺的插层反应具有相当明显的促进作用,反应时间从通常的几天缩短到几个小时。采用X-射线衍射、FT-IR光谱、TG等技术对其进行表征。结果表明:反应2小时后,该插层复合物的层间距即可扩大为1.139nm,其键合方式发生了改变,形成新的氢键。这为工业生产高岭石有机插层物以及制造纳米级高岭土提供了高效的新途径,并为进一步生产高性能陶瓷方面打下了基础。     

The effect of the molecular structure of a cationic azo dye on the photoinduced intercalation of phenol in a montmorillonite

The effect of the molecular structure of a cationic azo dye on the photoinduced intercalation of phenol into the azo dye-montmorillonites was reported. Two types of cationic azo dyes were used; one has (2-hydroxyethyl)dimethylammonium group (AZ(OH)⁺), and the other has trimethylammonium group (AZ(CH₃)⁺). Phenol was intercalated into both cation exchanged azo dye-montmorillonites (Kunipia F) by mechanical mixing without solvent. By the UV irradiation, the basal spacings increased further, and subsequent visible light irradiation led to decrease the basal spacings, indicating the intercalation and the deintercalation of phenol by the UV and visible light, respectively. The amounts of the phenol intercalated both chemically and photochemically varied depending on the azobenzene cations, showing the interactions between the cationic head group and phenol.     

Synthesis of polypropylene oligomer—clay intercalation compounds

The synthesis of polypropylene (PP) oligomer—clay intercalation compounds was studied by using three kinds of PP oligomers and organophylic clay. PP oligomers were two types of maleic-anhydride-modified PP oligomers containing different amount of maleic anhydride groups and one type of hydroxy modified PP oligomer. Organophylic clay was sodium-ion-exchanged montmorillonite with octadecylammonium ion (C18—Mt). PP oligomer was mixed with C18—Mt at 200°C. Maleic-anhydride-modified PP oligomer, which was of high acid value type, and hydroxy-modified PP oligomer were intercalated between silicate layers of clay; and PP oligomer—clay intercalation compounds were synthesized successfully. But maleic-anhydride-modified PP oligomer, which was of low acid value type, was not intercalated. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 1781–1785, 1997     

层状硅酸钠的制备及插层性能的研究进展

从晶体结构、制备工艺、插层改性和应用的角度,对层状硅酸钠的研究进行较全面阐述。介绍了层状硅酸钠存在的多种晶相及结构特点;指出了喷雾干燥结晶法或水热合成工艺在制备结晶层状硅酸钠中存在的技术问题;从反应类型的角度详细介绍了层状硅酸钠的插层改性技术和赋予改性层状硅酸钠丰富的功能性;分析了层状硅酸钠的不同晶相或改性技术在实际应用中的研究思路和存在问题,为层状硅酸钠的深度研究与开发指出方向。     

软模板法制备中孔碳材料及其对罗丹明B吸附性能的研究

采用软模板法合成了较大比表面积的中孔碳材料,通过XRD、FT-IR、SEM、N2吸附-脱附对样品进行了表征。并以所制备的中孔碳材料为吸附剂,以罗丹明B溶液模拟染料废水,进行了吸附脱色实验,考察了吸附时的pH值、温度、吸附剂加入量等因素对吸附性能的影响。研究发现在pH=1,吸附温度为25℃时,所合成的中孔碳材料对罗丹明B表现出了最好的吸附性能。     

Synthesis of fluorine-graphite intercalation compounds by elemental fluorine and high oxidation-state transition-metal fluorides

Fluorine-graphite intercalation compounds have been synthesized using high purity fluorine gas and high oxidation-state transition-metal fluorides, AgF₃ and NiF₃, at room temperature and at −78 °C. At room temperature, a mixture of stage 1 + 2 − 4 compounds with compositions, C_4.2F to C_14.6F were obtained. On the other hand, stage 2–4 compounds with compositions C_5.6F to C_14.2F were synthesized at −78 °C. The fluorinating ability of AgF₃ and NiF₃ has been shown more clearly at room temperature because a small amount of fluorine was intercalated/absorbed into graphite at −78 °C without catalysts. XPS spectra show that ionic, nearly ionic, semi-covalent and covalent fluorines coexist in the C_xF samples, and that the covalency of CF bonding increases with decreasing stage number.