表面活性剂改性有机沸石对废水中亚甲基蓝的吸附行为

用表面活性剂十六烷基三甲基溴化铵(CTMAB)和十二烷基硫酸钠(SDS)复合改性沸石,制备了阴阳离子表面活性剂改性沸石,利用X射线衍射和红外吸收光谱表征了改性前后沸石的结构,并研究了改性沸石对亚甲基蓝的吸附行为.结果表明,改性后沸石的吸附性能明显增强;在溶液pH 8、常温,吸附时间100 min、改性沸石用量20 g/...     

Modified bentonite by polyhedral oligomeric silsesquioxane and quaternary ammonium salt and adsorption characteristics for dye

To remove methylene blue dye from water by adsorption, bentonites were modified by polyhedral oligomeric silsesquioxane (POSS) and three kind of quaternary ammonium surfactants (dodecyl trimethyl ammonium bromide, tetrabutyl ammonium bromide, cetyl trimethylammonium bromide) in aqueous solution. Systematic adsorption experiments were carried out, the adsorption mechanism was studied, and the factors governing the adsorption of methylene blue on modified bentonite were discussed. The adsorption capacity of methylene blue on all three modified bentonites in 1000 mg·L⁻¹ solutions quickly reached equilibrium within 2000 s, and the removal rate was basically 100%; however, the removal rate in raw bentonite samples was only 60%. The pseudo second-order kinetic model can provide satisfactory kinetic data fitting. The obtained adsorption isotherms fit well with the Dubinin-Radushkevich isotherm model. The thermodynamic results showed that the adsorption process was a spontaneous endothermic physical adsorption process. With increasing pH and KCl concentration, the removal of methylene blue increased significantly. The results of this study confirmed that the modified bentonite is a candidate material as a cationic dye adsorbent.     

Poly(Amic Acid)-Modified Biomass of Baker’s Yeast for Enhancement Adsorption of Methylene Blue and Basic Magenta

In this study, poly(amic acid)-modified biomass was prepared to improve the adsorption capacities for two cationic dyes, methylene blue and basic magenta. X-ray photoelectron spectroscopy and potentiometric titration demonstrated that a large number of imide, amine, and carboxyl groups were introduced on the biomass surface, and the concentrations of these functional groups were calculated to be 0.27, 1.08, and 1.08 mmol g^?1 by using the first derivative method. According to the Langmuir equation, the maximum uptake capacities (q _m) for methylene blue and basic magenta were 680.3 and 353.4 mg g^?1, respectively, which were 13- and sevenfold than that obtained on the unmodified biomass. Adsorption kinetics study showed that the completion of the adsorption process needed only 40 min, which is faster than the common sorbent such as activated carbon and resin. Experimental results showed that pH and ionic strength had little effect on the capacity of the modified biomass, indicating that the modified biomass had good potential for practical use.     

苝酰亚胺接枝纤维素的合成与染料吸附性能

合成了一种新型苝酰亚胺接枝纤维素材料3,通过元素分析、红外、扫描电子显微镜等技术手段证明了其结构。 染料吸附实验表明其对所测试的4种染料分子（橙黄G,亮丽春红,亚甲基蓝和结晶紫）均有较好的吸附能力,吸附容量分别达到1.04、1.21、1.14和0.96 mmol/g。 吸附过程符合拟二阶动力学模型和Langmuir等温方程,吸附过程是自发放热的。 在pH值2~12范围内,聚合物3的吸附性能保持基本稳定。 由吸附实验结果推测,静电作用、氢键和π-π堆积均在吸附过程中有重要作用。     

改性埃洛石材料的制备及其对亚甲基蓝吸附行为的研究

使用硅烷偶联剂KH550改性埃洛石纳米管获得改性材料HNTs-APTS,并对其吸附亚甲基蓝的行为进行研究。利用傅立叶变换红外光谱仪(FTIR)、X-衍射仪(XRD)对改性前后的埃洛石进行表征。考察了吸附时间和温度对吸附过程的影响,并采用Lagrange准二级动力学方程、Langmuir等温线方程及Freundlich等温线方程对实验数据进行拟合。结果表明,KH550成功负载到埃洛石表面;改性后材料的吸附能力大大提高。改性埃洛石对亚甲基蓝的吸附约在60 min达平衡,最大吸附容量为21.66 mg/g。其吸附过程符合准二级动力学方程,热力学较好地符合Langmuir等温线方程,且吸附过程为自发吸热,升高温度有利于吸附的进行。改性材料可重复再生6次,具有良好的再生性能,可在工业处理亚甲基蓝废水中使用。     

Absorption of phenol and methylene blue by activated carbon from pecan shells

Activated carbon is produced from pecan shells by chemical activation using phosphoric acid. This activation is followed by the treatment with sodium dodecyl sulfate to prepare the surface for the adsorption of phenol and methylene blue from aqueous solution. The results showed a great ability for methylene blue removal with sorption capacity of 410 mg/g at pH 9 and solution concentration of 35 mg/l, while moderate adsorption was obtained for phenol with a capacity of 18 mg/g at pH 11 and the same solution concentration. The increase or decrease in solution pH has a favorable effect on the sorption of both adsorbates. Langmuir and Freundlich models were used to fit the experimental data. The text was submitted by the authors in English.     

Adsorption of the Dyes (Methylene Blue and Acridine Orange and Their Mixtures) from Aqueous Solutions on Cholesterol Surface

The adsorption of the dyes, methylene blue and acridine orange, from their aqueous solutions individually as well as in mixtures were investigated with respect to the variation of temperature and concentration of the KCl and the bile salt, sodium cholate. The features of different isotherms were presented and discussed. The isotherms obtained differ from those described by the Langmuir equation. The adsorption process was controlled by the ion-dipole and hydrophobic interactions. While KCl retarded the adsorption, the bile salt enhanced the process due to synergistic effect.     

正负离子表面活性剂混合体系中高稳定性囊泡的形成

对总浓度为0.01 mol/L，摩尔比为2：1的十二烷基硫酸钠/溴化十二烷基三乙 铵的正负离子表面活性剂混合体系形成的囊泡的稳定性进行了研究。发现这一体系 形成的囊泡在长放置（5个月）后依然存在。在加入较大量的无机盐（0.15 mol/L NaBr）、较大幅度pH变化（pH = 2～12）、温度变化（从80 ℃到-22 ℃）情况下 体系中的囊泡依然呈现出优异的稳定性。在非水溶剂乙醇（100%）中这类正负离子 表面活性剂仍然可以形成囊泡。     

ZnCl2改性离子交换树脂的制备及其催化乙醇和乙酸酯化反应性能

 采用离子交换法制备了 ZnCl2 改性的阳离子交换树脂催化剂, 考察了 ZnCl2 浓度、离子交换时间和溶剂等对催化剂催化乙酸和乙醇微波酯化反应性能的影响. 结果表明, 以去离子水为溶剂, 以 0.15%ZnCl2 溶液进行离子交换 30 h, 所得催化剂的性能较好. 采用酸碱滴定法、紫外-可见光谱、傅里叶变换红外光谱、扫描电镜和 N2 吸附脱附等手段对催化剂进行了表征. 结果表明, 改性后的催化剂 H+交换量约为原来的 1.5 倍, 表面酸强度增加; 树脂骨架结构变化不大; 紫外吸收峰发生蓝移, 吸收强度减小; 比表面积略有减小; 催化剂在含水体系中表现出较高的催化活性, 且重复使用性能大大提高.     

H_6P_2Mo_(18)O_(62)/Zn(BDC)(Bipy)_(0.5)复合材料的合成、表征及对亚甲基蓝的吸附

在溶剂热条件下,以H6P2Mo18O62、对苯二甲酸(H2BDC)、4,4'-联吡啶(Bipy)和硝酸锌为原料构筑了1个三维金属有机骨架复合材料H_6P_2Mo_(18)O_(62)/Zn(BDC)(Bipy)_(0.5),并采用红外光谱(IR)、X射线衍射(XRD)、扫描电子显微镜(SEM)、热重分析(TG)、N2吸附-脱附等手段对产物进行了表征.同时,研究了产物对水溶液中亚甲基蓝(MB)的吸附性能,并探讨了MB初始p H值、初始浓度和温度对吸附量的影响.结果表明,产物的等温吸附模型符合Langmuir等温吸附模型,动力学符合拟二级动力学.H_6P_2Mo_(18)O_(62)/Zn(BDC)(Bipy)_(0.5)对亚甲基蓝的吸附是自发和放热的,此外,产物对甲基紫、罗丹明B、孔雀石绿等阳离子染料也具有良好的吸附性能.     

SDS改性沸石对碱性品红的吸附性能研究

通过静态实验探讨了表面活性剂十二烷基硫酸钠（SDS）改性沸石吸附碱性品红的影响因素。实验结果表明在投入量为8 g/L、吸附时间为45 min、p H值为6、温度为25℃时,对初始质量浓度100 mg/L碱性品红溶液的去除率可达到96.16%,吸附量为12.02 mg/g;SDS改性沸石吸附碱性品红的吸附性能符合Langmuir型吸附等温线和一级反应动力学模型的特征;热力学分析结果表明,吸附符合自发吸热过程。     

Surface chemical modification to control molecular interactions with porous silicon

Interactions between porous silicon (pSi) particles and probe molecules were evaluated to determine the effect of pSi and probe molecule chemistry on adsorption. Methylene blue, ethyl violet and orange G dyes were chosen for investigation as they possess distinct functionalities and charges. Several distinct pSi surface species were produced via thermal oxidation at 200-800 °C and their effect on adsorption investigated. The adsorption mechanisms were elucidated from equilibrium adsorption and desorption isotherms. Methylene blue adsorption was attributed to electrostatic attraction where a gradual increase in adsorption with oxidation temperature was observed. Significant methylene blue desorption was observed at pH 3, confirming adsorption occurs via electrostatic attraction. Ethyl violet demonstrated an increase in plateau adsorption capacity and affinity with increased oxidation temperatures and adsorption was initially attributed to electrostatic attraction, however desorption of ethyl violet was not observed, thus indicating potential chemisorption. Orange G exhibited high affinity adsorption for Si(y)SiH(x) terminated surfaces but no orange G desorption was detected, indicating a chemisorption adsorption mechanism. It has been successfully demonstrated that the surface modification of pSi enabled the manipulation of molecular interactions. By interacting probe molecules with similar functionalities to drug molecule with pSi, greater understanding of drug-pSi interactions can be ascertained which are of great importance. pSi surface chemistry can be tailored to enable control over molecular interactions and ultimately dictate loading, encapsulation and release behavior.     

Synthesis and characterization of small-mesopore-added silicalite-1 zeolites using single wall carbon nanohorn templating

Small-mesopore-added silicalite-1 zeolites were prepared by using single wall carbon nanohorn (SWCNH) as a template. The samples were characterized with X-ray powder diffraction, field emission scanning electron microscopy, transmission electron microscopy (TEM) and molecular probe adsorption methods. The pore size distributions determined with N₂ adsorption at 77 K showed the presence of small mesopores in 2–4 nm pore widths, in addition to their intrinsic micropores of 0.58 nm. The mesopore volume was 0.06 cm³ g^?1. The presence of small mesopores in the SWCNH-templated silicalite-1 zeolites was supported with TEM observation as well as the liquid phase adsorption of methylene blue, which was much higher than that on a bulk (purely microporous) silicalite-1.     

Mesoporous spherical aggregates of anatase nanocrystals with wormhole-like framework structures: their chemical fabrication, characterization, and photocatalytic performance

A facile and efficient approach for the fabrication of mesoporous spherical aggregates of anatase nanocrystals is reported in this paper. Cetyltrimethylammonium bromide was used as the structure-directing agent, and the interaction between cyclohexane microdroplets and the cetyltrimethylammonium bromide self-assemblies led to the assembly of 4-5-nm-sized anatase nanocrystals into spherical aggregates with mesoporous structures. The as-prepared anatase powders exhibited high photocatalytic activity and could be effectively used as the catalyst for the room-temperature photodegradation of a variety of organic dye pollutants in aqueous media including methyl orange, bromopyrogallol red, and methylene blue.     

磷酸锆镍的微波制备及其可见光光催化性能

以氧氯化锆、氯化镍和磷酸二氢钠为原料,在较低温度和常压条件下采用微波辅助法制备具有特殊形貌的磷酸锆镍NiZr(PO_4)_2·4H_2O。研究了3种不同种类的表面活性剂对磷酸锆镍的物相、尺寸及形貌的影响。结果表明,表面活性剂的引入可以降低磷酸锆镍颗粒的平均粒径。与十二烷基硫酸钠(SDS)相比,聚乙烯吡咯烷酮K30(PVP-K30)和十六烷基三甲基溴化铵(CTAB)对颗粒生长的抑制程度更大,从而产物的平均粒径更小。使用亚甲基蓝(MB)溶液模拟印染废水,对磷酸锆镍的光催化降解性能进行了探讨。结果表明,可见光下以PVP-K30为模板制备的磷酸锆镍对MB的表观脱色率为49.0%,优于CTAB和SDS条件下制备的磷酸锆镍。本文为新型磷酸锆类复盐的制备与应用研究提供了新的思路和方法。     

胶束对酸碱指示剂离解平衡和变色点及变色范围的影响

探讨了十六烷基三甲基溴化铵(CTMAB),十二烷基硫酸钠(SDS)和TritonX-1003种胶束对酸套指示剂百里香酚蓝和溴百里香酚蓝离解反庆的离解常数的影响,进行了研究了以上3种胶束对指示剂变色点的变以范围的影响,实验结果表明,选择适当的胶束溶液作为滴定介质,不仅可以扩大酸碱指示剂的应用范围,而且还大大提高了测量的准确度.     

The influence of titanium dioxide phase composition on dyes photocatalysis

A comparative study of TiO₂ powders prepared by sol–gel methods is presented. Titanium tetraisopropoxide was used as the precursor for the sol–gel processes. The effects of the annealing treatment on phase, crystallite size, porosity and photodegradation of dyes (methyl orange and methylene blue) were studied. The phase structure, microstructure and surface properties of the films were characterized by using X-ray diffraction (XRD) and Atomic Force Microscopy (AFM). The X-ray diffraction was used for crystal phase identification, for the accurate estimation of the anatase–rutile ratio and for the crystallite size evaluation of each polymorph in the samples. It was found that the only TiO₂ anatase phase of the synthesized TiO₂ develops below 500 °C, between 600 and 800 °C the anatase coexist with rutile and above 800 °C only the rutile phase was found in the samples. Attention has been paid not only to crystal structures, but also to the porosity, the particle size and the photocatalytic properties. However, the annealing temperature was found to have significant influence on the photocatalytic properties. Different TiO₂ doctor blade thin films were obtained mixing the sol gel powder (100% anatase) and TiO₂ Aldrich with TiO₂ Degussa P25. The surfactant (Triton X100 or sodium dodecyl sulfate) affects the packing density of the particles during deposition and the photocatalytic degradation efficiency of the dyes. The photocatalytic degradation kinetics of methyl orange and methylene blue using TiO₂ thin film were investigated.     

Extraction of water miscible organic dyes by reverse micelles of alkyl glucosides

The extraction of methyl orange or methylene blue from an aqueous phase to an organic phase of reverse micelles of alkyl glucosides was investigated. Dodecyl glucoside, a biodegradable and biocompatible surfactant, was employed as a kind of alkyl glucosides, since a stable Winsor II system consisting of the water-in-oil type microemulsion and aqueous phases was formed when an organic solution containing dodecyl glucoside was contacted with an aqueous solution. The water content in the reverse micellar organic phase increased with an increase in the concentration of dodecyl glucoside. The extraction ratio of dyes also increased with increasing the concentration of dodecyl glucoside. Furthermore, the extraction ratio of dyes was dramatically dependent upon the pH of an aqueous phase and temperature.     

碳酸氢钠溶液中微量 Mn2+离子催化氧化降解有机污染物

 考察了微量 Mn2+离子在 NaHCO3 溶液中催化 H2O2 氧化降解有机污染物的性能. 结果表明, NaHCO3, MnCl2 和 H2O2 浓度分别为 25, 0.1 和 100 mmol/L 时, 在 25 oC 下反应 180 min 后亚甲基蓝可完全脱色, 化学耗氧量和总有机碳去除率分别达到 44.0% 和 13.8%. 该催化体系对甲基橙、罗丹明 B 以及垃圾渗滤液等都有较好去除效果. 紫外-可见光谱分析及反应动力学测试表明, MnIV=O 是该催化体系主要活性物种.     

Removal of methylene blue dye from an aqueous media using superabsorbent hydrogel supported on modified polysaccharide

The removal of methylene blue (MB) in water with the superabsorbent hydrogel (SH) formed by modified gum arabic, polyacrylate, and polyacrylamide was investigated. The SH exhibited excellent performance in MB absorption. The maximum absorption capacity was 48 mg of the dye per g of SH, representing 98% of the MB removed. Experimental parameters were used as follows: pH 8, hydrogel mass 50 mg, and initial concentration of MB 50 mg L(-1). In a procedure with an individual solution of orange II, an opposite effect related to the MB was observed: the hydrogel only absorbed water, resulting in an orange II-richer solution. The orange II concentration in solution increased about 50 times (relative to the initial concentration). In another experiment using an aqueous mixture of orange II and MB, the SH absorbed the MB exclusively. Compared to the MB, the orange II is separated from water by SH selectivity-absorption through an inverse process. This effect was attributed to the formation of a ionic complex between the imine groups of MB and the ionized carboxylic groups of SH.