细菌纤维素膜渗透汽化分离二元有机物水溶液

采用动静结合的方式制备出了细菌纤维素膜。以乙醇水溶液、丙酮水溶液、乙酸水溶液为研究对象,研究了渗细菌纤维素膜的吸附性能,并讨论了透汽化过程中原料液浓度、温度对分离效果的影响及渗透汽化过程中可能的分离机理。结果表明,细菌纤维素膜能够优先透水,在渗透汽化分离乙醇和丙酮时,渗透通量随浓度的上升呈下降的趋势,温度对渗透通量的影响基本符合Arrhenius方程渗透汽化分离二者时,分离因子随浓度的增加先增加后减小。渗透汽化分离乙酸时,渗透通量随浓度的上升呈先上升后下降的趋势,分离因子变化不明显,温度对渗透通量的影响偏离Arrhenius方程较明显。     

分离有机物水溶液的渗透汽化与汽化渗透膜

该文基于４５篇最新文献，较详细地论述了渗透汽化膜与汽化渗透膜的有机物水溶液分离性能及其影响因素，包括高聚物特征，料液浓度，温度，古游侧压力，膜厚度和操作时间，指出用多数高聚物膜进行渗透汽化操作可以有效地分离多数有机醇，酮，酸，酯，酰胺以及二Ｅ烷，乙腈，吡啶，二甲亚砜和四氢呋喃水溶液；而以壳聚糖及其衍生物膜进行汽化渗透操作则具有更高的分离系数。该文还简要介绍了渗透汽化膜的新应用。为渗透汽化与汽化渗透     

渗透汽化膜的制备及其应用进展

渗透汽化（pervaportion, PV）作为一种新颖的分离技术在工业范围内得以应用,至关重要的是它在恒沸混合物、近沸混合物分离方面的显著优势。相比分馏、精馏、萃取等传统分离方法,渗透汽化技术具有经济、高效、便于管理的优点,但目前缺少优质的渗透汽化膜材料和先进的膜制备方法。本文综述了近年来渗透汽化技术以及渗透汽化膜的研究现状,首先介绍了PV技术的分离机理、PV膜的制备方法、PV技术在工业上的应用领域等,并重点讨论了料液温度、料液浓度、料液流速、膜上下游蒸汽压差、膜材料等关键因素对渗透汽化分离性能的影响。文中提出未来渗透汽化技术应在膜材料方面积极探索,选用聚合物为材料,并结合先进的膜制备方法来进一步降低膜的厚度,从而明显地提高膜渗透通量。     

渗透汽化法分离丙酮水溶液

用自制的ＰＶＡ／ＰＡＮ渗透汽化复合膜进行丙酮脱水的研究。实验研究了不同操作温度对分离系数及渗透通量的影响，并考察了该复合膜在丙酮水溶液中的耐久性。     

优先透过有机物渗透汽化膜研究进展

近年来膜分离技术被广泛应用于有机物的分离回收。渗透汽化能有效地分离共沸混合物、近沸混合物、异构体和热敏性化合物等有机物。渗透汽化以成本低、条件温和、设备简单、无污染等优点在有机物分离回收领域有着巨大优势，可广泛的应用于工业生产。该文以优先透过有机物为主旨，首先分析了材料对膜结构和特点的影响。其次综述了制备方法和改性方法对膜性能的影响。重点讨论了膜在有机混合物分离回收领域的应用。最后，对目前渗透汽化技术所存在的问题做出了总结，对未来的研究方向和研究思路进行了展望。未来优先透过有机物渗透汽化膜的研究应借助新的计算工具，侧重于材料选择、制备方法和改性方法的改进，如探索具有多功能化学基团和具有明确层次结构的多孔填料的聚合物材料等，使优先透过有机物渗透汽化膜具有更加广阔的应用前景。     

渗透蒸发脱除水溶液中挥发性有机物

制备了用于渗透蒸发的聚二甲基硅氧烷 (PDMS)硅橡胶膜 ,考察了其从水溶液中脱除苯和氯仿的渗透蒸发性能。分析讨论了料液浓度、温度和雷诺数等因素对膜渗透蒸发性能的影响。本研究中所制备的渗透蒸发膜的分离性能优于国外文献值     

甲醇／正己烷的渗透汽化分离的研究：I.渗透汽化膜的研制

本文研制了从甲醇／正己烷体系中分离甲醇的渗透汽化复合膜ＣＡ／ＰＡＮ（ＰＥＳ）、ＰＶＡ／ＰＡＮ（ＰＥＳ）。实验证明膜对该体系有较高的选择分离性和良好的渗透性，当进料甲醇浓度为３％时，渗透通量Ｊ≈０．６００ｋｇ／ｈ·ｍ＾２，分离因子α→∝。本文还考察了不同操作条件对膜分离性能的影响及膜的稳定性和均匀性。     

金属离子固载膜及其有机物的渗透汽化分离

在简要介绍了金属离子固载促进传递膜制备方法的基础上，分析了金属离子和反离子的种类、分离体系的温度和膜厚度等对金属离子固载膜分离性能的影响；并对金属离子固载促进传递膜在烯烃／烷烃、苯／环己烷等有机物体系分离中的应用进行了综述。     

聚氨酯渗透汽化膜的研究进展

聚氨酯膜材料具有良好的选择性、渗透性和力学性能等,近年来在渗透汽化领域倍受关注。本文综述了用于渗透汽化分离的聚氨酯及其改性膜的研究情况及最新进展,重点评述了以聚丁二烯、聚酯和聚醚为软段的PU渗透汽化膜材料结构特点、合成方法、分离性能,以及共混、填充和接枝3种改性方法的反应原理,改性思路、对PU膜分子结构和分离性能的影响等;同时分析了不同材料和改性方法在渗透汽化膜分离方面的优点和不足。在此基础上,对用于渗透汽化分离的聚氨酯膜材料发展方向和研究前景进行了展望。     

有机/有机混合物渗透汽化分离膜材料的研究进展

综述了有机，有机混合物渗透汽化分离膜材料的最新研究进展，详细讨论了共混膜、共聚膜以及改性膜的研究情况，并对渗透汽化膜材料的研究前景进行了展望。     

Pervaporation separation of levulinic acid aqueous solution by ZSM-5/PDMS composite membrane

This work aims at investigating the special application of ZSM-5/polydimethylsiloxane (PDMS) membrane being used for pervaporation separation of levulinic acid aqueous solutions. The effects of temperature, downstream pressure, feed concentration, and raw material ratio on the separation performance are investigated by self-made flat-sheet films. When the flow rate of feed pump remained at 0.4 ml/min (10 wt% levulinic acid), a levulinic acid permeation flux of 334.13 g/(m²h) and a separation factor of 2.382 at 75°C are observed over the composite membrane doped with 10 wt% ZSM-5. In addition, the acid resistance is enhanced after the PDMS membranes are doped with ZSM-5. Besides, the functionalized process also makes the membranes increase in its hydrophobicity. The results demonstrate that the ZSM-5/PDMS-based membranes show profound prospects for separating levulinic acid aqueous solution.     

Pervaporation separation of aqueous organic mixtures through sulfated zirconia‐poly(vinyl alcohol) membrane

Sulfated zirconia‐poly(vinyl alcohol) membranes were prepared, and pervaporation performances for aqueous organic mixtures were investigated. These hydrophilic membranes were formed by crosslinking poly(vinyl alcohol) (PVA) with the solid acid of sulfated zirconia by an acid‐catalyzed reaction. The pervaporation performances were measured as a function of the content ratio of sulfated zirconia to PVA, which affected the degree of swelling for water and the crosslinking density of the membrane. The membrane selectivity in pervaporation of aqueous organic mixtures increased in order of acetic acid < ethanol < 2‐ethoxyethanol without sacrificing the permeation rate, depending on their feed compositions. The effects of feed temperature and concentration on the membrane performance were also significant. It was found that sulfated zirconia in the membrane preparation played an important role as a filler material as well as an effective crosslinking or insolubilization agent in improving and controlling the membrane performance, i.e., permeation rate and selectivity. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 1450–1455, 2001     

Pervaporation removal of volatile organic compounds from aqueous solutions using the highly permeable PIM‐1 membrane

Wastewater containing volatile organic compounds (VOCs) is generated in various industrial processes and is seriously harmful to the natural environment and human health. Its treatment has become extremely important due to increasing environment concerns. Here, a high permeable membrane for fast and high‐efficient VOCs removal from aqueous solutions by pervaporation is reported. The as‐prepared PIM‐1 membrane allows ultrafast permeation of VOCs and exhibits excellent VOCs selectivity, particularly for ethyl acetate, dimethyl ether, and acetonitrile. Typically, the PIM‐1 membrane exhibits an ultrahigh flux and separation factor of 39.5 kg μm m^?2 h^?1 and 189, respectively, in the pervaporation of 1.0 mol% aqueous ethyl acetate solution. Furthermore, the solubility‐diffusion mechanism is revealed in the pervaporation of 10 kinds of 1.0 mol% VOCs solutions. It is found that the pervaporation performance is affected directly by physicochemical properties of VOCs. Moreover, effects of feed composition and temperature on the pervaporation are studied in details. © 2015 American Institute of Chemical Engineers AIChE J, 62: 842–851, 2016     

Pervaporation dehydration of ethyl acetate aqueous solution using the doubly modified polyvinyl alcohol (PVA) composite membrane

Polyvinyl alcohol–tetraethoxysilane–perfluorosulfonic acid (PVA–TEOS–PFSA) hybrid membrane was prepared by sol–gel method through PVA being modified doubly by PFSA and TEOS. With polyacrylonitrile (PAN) ultrafiltration membrane as a substrate membrane, PVA–TEOS–PFSA/PAN composite membrane was fabricated by dip-coating method for pervaporation (PV) dehydration of ethyl acetate (EAc) aqueous solution. The hybrid membrane was characterized by swelling degree, static contact angle, Fourier transform infrared spectra and scanning electron microscope. Effects of PFSA and TEOS contents in coating solution on PV performance of composite membrane were investigated, respectively. With increasing PFSA content, the permeation flux of composite membrane increased, while the separation factor decreased. Just the opposite, the increase of TEOS content resulted in the decrease in permeation flux and the increase in separation factor. In addition, the PV performances of composite membranes were also investigated at different feed temperatures and water concentrations in feed, respectively. The PVA–TEOS–PFSA/PAN composite membrane, which was prepared from coating with PVA/PFSA mass ratio of 80/20 and TEOS content of 20 wt%, exhibited the permeation flux of 347.9 g m^?2 h^?1 and the separation factor of 2218 for PV dehydration of 2 wt% water of EAc solution at 40 °C.     

聚环糊精填充PDMS渗透蒸发膜分离苯酚水溶液

以聚二甲基硅烷为预聚体,正硅酸乙酯为交联剂,二丁基二月桂酸锡为催化剂,三氯甲烷或正庚烷为溶剂,通过相转化法制备得到了空白聚二甲基硅氧烷（PDMS）膜和聚环糊精（CDP）填充PDMS（CDP-f-PDMS）膜.考察了空白PDMS膜和CDP-f-PDMS膜对苯酚水溶液的渗透蒸发分离性能,证明填充膜优于空白膜.还分别考察了溶剂类型、填充剂用量等制膜因素和操作温度、原料液流量、原料液浓度等操作因素对PDMS膜的渗透蒸发分离性能的影响.当温度为60℃,CDP填充量为1%（质量）时,CDP-f-PDMS膜的渗透通量和分离因子分别可达32.0 g&#8226;m-²&#8226;h^-1和7.2.     

细菌纤维素膜的合成及表征

以海南椰子水为主要培养体系,实验室自行筛选的木醋杆菌(Acetobacter xylinum)为菌种,采用静态培养方法制备了细菌纤维素（BC）。对该BC和商业BC的结构和性能进行了测试对比,观察BC的微结构特点。结果表明: 制备的BC和商业BC在结构和一些性能方面是相似的,都是无色透明膜,呈三维网状结构和孔洞结构,具有良好的纳米纤维网络特征, 具有良好的吸湿性和极佳的持水能力,本实验制备的BC生产成本低,可根据需要大量制备,在生物医学领域具有良好的、广泛的应用前景。     

Activated carbon from bacterial cellulose as an effective adsorbent for removing dye from aqueous solution

ABSTRACT

Novel activated carbon (AC) derived from bacterial cellulose (BC-AC) was produced by phosphoric acid activation at a carbonization temperature of 500 °C. BC-AC possesses mesoporous structures of 2.3 nm in diameter, porosity of 1.0 cm³/g and surface area of 1734 m²/g with high thermal stability between 100 and 500 °C. BC-AC could be used as an effective adsorbent for removing methylene blue (MB) from aqueous solutions with the maximum adsorption capacity of 505.8 mg/g. BC-AC presented physisorption and the adsorption of MB was most likely to be a monolayer adsorption. The Redlich–Peterson model displayed the best fit with the experimental data.     

纤维素在NMMO水溶液中的溶胀行为研究

通过离心分离法表征纤维素在N-甲基吗啉-N-氧化物水溶液中的溶胀行为,研究了NMMO浓度、温度对纤维素浆粕溶胀的影响;用显微镜追踪拍摄纤维素的溶胀过程,测定纤维的溶胀率,验证了离心分离法的可行性。结果表明:随着NMMO浓度、溶胀温度的升高,纤维素溶胀率增大,溶胀效果变好;纤维素在NMMO水溶液中的最佳溶胀条件为NMMO质量分数78%、温度75℃,溶胀时间40 min。     

Ni-NiO/纳米石墨烯圆筒状结构复合材料的制备

木质纤维素GO化学镀Ni制备可控形貌与尺寸的特定Ni-NiO/GO圆筒状结构,探讨化学镀Ni时间对木质纤维素表面微观形貌的影响,利用扫描电镜和激光共聚焦显微镜探究复合镀层表面形貌,采用FTIR和XRD分析复合镀层的官能团和晶型结构。结果表明,随着化学镀时间的延长,木质纤维素线粗糙度呈现下降趋势,表面亮度增加。当木质纤维素化学镀时间为20 min时,其表面粗糙度(Ra值)较小,平均值为1.79μm。纳米颗粒诱导形成更小粒径Ni和P粒子,促使镀层内粒子分布更紧密。纳米石墨烯添加不会改变圆筒状结构表面固有晶态结构。