纳米载银抗菌陶瓷

阐述了用来生产抗菌性日用瓷、卫生瓷和墙地砖等产品的纳米载银型无机抗菌剂(磷酸锆载银)的制备、性能、抗菌机理以及研究现状。     

不同价态阳离子对ZrO2纳米晶涂层修饰微滤膜的相互作用研究

分别在CaCl2和KCl稀溶液中,用AFM研究了四方相ZrO2纳米涂层的表面排斥力随作用距离的变化关系。Ca2＋在ZrO2纳米涂层表面具有特征吸附,而K＋表现出惰性电解质的特征。随着CaCl2浓度的升高,ZrO2纳米晶涂层表面的双电层受到压缩,其排斥力的作用范围缩小,排斥力的强度呈下降趋势。随着CaCl2浓度的增大,渗透通量呈明显下降的趋势。随着KCl浓度的增大,渗透通量呈稍有增大的趋势。所产生的短程非DLVO作用力可能来源于Ca2＋的特征吸附。     

载银纳米二氧化钛的制备及抗菌性能研究

以碳酰二胺为沉淀剂与TiOSO4溶液反应生成Ti(OH)2沉积于AgCl晶种表面制备载银纳米二氧化钛,产物对金黄色葡萄球菌(S.aureus)、大肠杆菌(E.coli)和白色念珠菌(C.albicans)达到99%抗菌率的最小浓度分别是90、70、60 mg/L,经电子透射显微镜(TEM)表征,粒径主要分布于100～200 nm。     

载银纳米二氧化钛镀膜抗菌陶瓷的研究进展

从抗菌陶瓷的国内外发展现状出发,简要地介绍了其特点及存在的问题,并结合二氧化钛光催化抗菌剂的固定化(薄膜化)技术,对载银纳米二氧化钛镀膜抗菌陶瓷的开发进行了可行性方案的探讨,展望了其发展前景。     

载银纳米二氧化硅抗菌粉体材料的制备

研究了以平均粒径13nm的二氧化硅为载体，银单质为抗菌剂的载银纳米抗菌粉体材料的制备工艺及抗菌性能。通过化学还原法在其表面负载理论含量为0．7％～4％（质量分数）金属银，采用抑菌环法和振荡烧瓶法对其抗菌性能进行了检测，结果表明，载银3％（质量分数）的纳米二氧化硅在80～140℃烧结温度范围内制得抗菌粉体对大肠杆菌和金黄色葡萄球菌的杀菌率几乎达到100％，具有优良的抗菌性能，可用于抗菌塑料、抗菌食品包装和抗菌纺织制品等领域。     

纳米载银抗菌粉体材料的制备工艺与性能

本研究采用纳米粒子制备技术,制成的纳米磷酸锆载银抗菌粉体材料,具有颗粒尺寸小、抗菌谱广、高效、无毒、持久和耐热性。     

载银纳米二氧化钛在抗菌塑料中的应用研究进展

对载银纳米二氧化钛(Ag/TiO2)抗菌剂的抗菌性能、制备方法以及抗菌机理等进行了分析与总结。根据Ag/TiO2抗菌剂的特点,介绍了添加Ag/TiO2抗菌剂的抗菌塑料的一般制备方法,最后介绍了该类抗菌塑料的潜在应用。     

氧化锆微滤膜处理冷轧乳化液废水的研究

本文对氧化锆微滤膜处理冷轧乳化液废水的过程进行了研究 ,主要考察了强化传质及高频反冲对延迟膜的污染 ,降低操作能耗的影响 ;对膜污染层进行了微观分析 ,并对各种清洗剂的清洗效果进行了比较 ,得出了膜通量基本恢复的清洗方法 ,并且考察了清洗的重复性 ,确定了效果好且稳定的清洗方法 ,为工业化的进一步应用奠定了基础     

纳米SiO2载银抗菌剂的研究

以化学沉淀法制备得到多孔纳米SiO2,采用吸附法在其表面负载银,用载银的粉体抑菌圈直径表征抗菌性能。研究了吸附时间、硝酸银浓度及吸附温度与负载量的关系,并考查了焙烧温度与抗菌性能的关系。     

纳米SiO2载银抗菌剂的研究

以化学沉淀法制备得到多孔纳米SiO2,采用吸附法在其表面负载银,用载银粉体的抑菌圈直径表征抗茵性能,研究了吸附时间、硝酸银浓度及吸附温度与负载量的关系,并考察了焙烧温度与抗菌性能的关系。     

陶瓷微滤膜涂膜液的分散性能研究

本文研究了分散剂种类及数量、pH值对陶瓷微滤膜涂膜液分散性能的影响，找出了适宜的分散剂及其使用条件。结果表明：在pH=9～11时，加入0．2wt％～0．8wt％的PAA，制出的涂膜液具有良好的稳定性。     

纳米ZnO涂层对Al2O3微滤膜的改性

以硝酸锌、尿素为主要原料，采用均相沉淀法对Al2O3微滤膜进行了纳米ZnO的涂覆改性研究，着重考察了反应温度与涂覆次数对改性作用的影响。用TEM，FTIR，zeta电位分析仪等对改性涂层进行测试分析。探讨了改性机理。实验结果表明：制备的ZnO改性涂层光滑致密，晶粒为5～10nm，使改性后的Al2O3微滤膜水通量提高了43％。可以认为ZnO改性涂层荷电是促使改性后Al2O3微滤膜水通量提高的主要原因。其次，改性涂层的疏水性及形成的改性涂层光滑致密也对水通量提高起一定作用。     

MODELING OF MEMBRANE FOULING AND FLUX DECLINE IN MICROFILTRATION OF OILY WASTEWATER USING CERAMIC MEMBRANES

One of the major problems in pressure-driven membrane processes is reduction of flux far below the theoretical capacity of the membrane. The results of an experimental study of fouling mechanisms of ceramic membranes in separation of oil from synthesized oily wastewaters are presented. Mullite microfiltration (MF) membranes were synthesized from kaolin clay as MF ceramic membranes. The rejection of total organic carbon (TOC) for the synthetic feeds was found to be more than 94% by these membranes. Hermia's models were used to investigate the fouling mechanisms of membranes. The effect of pressure, cross flow velocity (CFV), temperature, oil concentration, and salt concentration on flux decline were investigated. The results showed that the cake filtration model can well predict the flux decline of mullite ceramic membranes; average error of this model is less than 7%. The results show that by increasing pressure from 0.5 to 4 bar, porosity of the cake layer on the mullite membranes decreases from 25.68% to 14.98%. After the cake filtration model, the intermediate pore blocking model was found to well predict the experimental data with an average error less than 10.5%.     

陶瓷微滤膜的亲疏水性变化对水通量的影响

用高温气相裂解色谱和FTTR对经钛酸酯偶联剂改性前或后的陶瓷微滤膜进行了表征,用非水溶液滴定法检测了修饰前后羟基的变化,改性后的陶瓷微滤膜粉体表面的亲油化度大幅度上升、吸水率大幅度下降.在一定的压力范围内,随着陶瓷微滤膜微孔道内壁的亲水性的下降和疏水性的增强,水的渗透通量呈明显下降趋势,当达到一定的疏水程度后,水的渗透通量趋近于零.     

动态陶瓷微滤膜净化沐浴污水实用研究

利用自制的动态陶瓷微滤膜对沐浴污水进行了处理,根据处理水质指标及膜操作参数的比较,发现在0.15MPa以下时,膜通量随压力的升高明显增加,大于0.15MPa时,压力对膜通量的影响不明显。合适的操作压力是0.1～0.15MPa,稳定通量为90～110L/m2·h。不同压力出水CODCr去除率达87%～98%、浊度从120°降到3°以下,处理后颜色为无色。并根据实验结果进行了工程化工艺初步设计和经济分析。     

PULSED ELECTROCHEMICAL CLEANING OF INORGANIC MICROFILTRATION MEMBRANES

The effect of the application of pulsed electric fields during cross-flow microfiltration has been studied at two novel types of inorganic membrane. Pulsed electrophoretic membrane cleaning was shown to be a very effective, improving filtration rates at anodic film membranes (Anopore) by factors of up to 6.5 under the conditions studied. Improvements were also measured at zirconia membranes (Ceramesh). The incorporation of a mesh in these latter membranes allowed direct use of the membrane as an electrode, giving a potential simplification in module design. Application of a force balance model incorporating changes in the resistances to flow on application of the electric field showed that the likelihood of membrane cleaning depended on the interplay of two opposing phenomena of comparable magnitude-particle electrophoresis and membrane/filter cake electro-osmosis. However, due to the complexity of the phenomena involved, such an approach can not readily lead to a quantitative prediction of the effectiveness of membrane cleaning. KEYWORDS: Membrane, Filtration Microfiltration, Electrofiltration, Electrophoresis.     

陶瓷膜微滤技术澄清苦参水提液的研究

用无机陶瓷微滤膜对苦参水提液进行微滤，对水提液微滤前后在性状，固形物，指标成分等方面进行对比分析。苦参水提液微滤前均为浑浊液体，微滤后成为颜色变浅的澄清透明液体，苦参水提液固形物去除率为39.50%，氧化苦参碱和苦参总黄酮的保留率分别为79.72%和77.23%。     

PERFORMANCE CHARACTERISTICS OF A CERAMIC MEMBRANE SYSTEM FOR MICROFILTRATION OF CORN STARCH HYDROLYSATE

A ceramic microfiltration membrane was used for the clarification of corn starch hydrolysate, having a dextrose equivalence of 95, to study the effect of process variables (transmembrane pressure, cross-flow velocity, and feed concentration) on permeate flux. Flux increased with increased cross-flow velocity for all transmembrane pressures and feed concentrations up to a volume concentration ratio of 100. Flux became asymptotic at pressures of 200-375kPa, indicating that microfiltration performance was limited by concentration-polarization. The optimum transmembrane pressure was higher at higher cross-flow velocities. A process model based on the resistances-in-series concept adequately described the observed variation of permeate flux with process variables such as transmembrane pressure, cross-flow velocity and feed concentration. Resistance due to concentration polarization decreased linearly with increase in cross-flow velocities for all feed concentrations, while fouling resistance increased linearly with increase in feed concentration.     

聚电解质对TiO2悬浮体系微滤过程的影响

以硫酸法钛白生产中TiO2的回收与分离为应用背景,研究了聚电解质对陶瓷膜微滤过程的影响。研究表明,不同功能团的聚丙烯酰胺对过程的影响不同,溶液pH值、聚丙烯酰胺分子量以及浓度对微滤过程都有影响。与传统的絮凝助滤不同,聚电解质在微滤过程中的应用必须考虑其对膜本身的污染问题。