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银系无机抗菌材料研究进展 总被引:2,自引:1,他引:1
系统论述了国内外银系无机抗菌材料的研究和应用现状,重点介绍了纳米银颗粒和载银型两类无机抗菌材料,包括它们的种类、制备方法、抗菌机理及其在各种制品中的应用等。纳米银无机抗菌材料制备方法主要有物理法、化学法和生物法,载银型无机抗菌材料根据载体不同分为沸石、蒙脱石、可溶性玻璃、羟基磷灰石和磷酸盐等类型。银系无机抗菌材料在医疗用品、陶瓷、塑料、涂料等制品上已得到大量应用,但其潜在毒性和生物安全性还有待进一步关注。最后提出了银系无机抗菌材料还需深入研究的问题和今后的发展前景。 相似文献
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无机材料作为抗菌剂进入人们的视野以来,其材料特性与抗菌机理不断得到研究.无机抗菌材料主要分为金属离子型(如Ag、Cu、Zn等)与金属氧化物光催化型(如TiO2、ZnO等),将其制备成纳米级材料后,其由于比表面积增大,可以更好地吸附于微生物,获得更好的抗菌效果.同时,相比于有机抗菌材料和天然抗菌材料,无机抗菌材料具有毒性低、稳定性高、耐久性好、不容易引起细菌耐药性的优点.然而,近些年对无机抗菌材料抗菌机理的提出与研究缺乏系统的分析和论证,大部分研究人员仅对某一金属型抗菌材料提出该种材料的抗菌机理.银系抗菌材料的抗菌机理是无机抗菌材料中研究较为深入的,一般认为银系抗菌材料释放出Ag+,Ag+吸附于细菌表面,然后击穿细胞膜进入细胞内部与细胞内容物发生反应,最后导致细菌失活.而金属氧化物光催化型(如TiO2)抗菌材料由于其较宽的光学带隙在光照的条件下可发生光催化反应,从而产生大量如·OH、·O2-一类的自由基,当这些自由基与细胞接触时,与细胞内有机物反应,导致细菌失活.本文归纳了各种无机材料的抗菌机理研究方式及内容,并对其进行了总结分析,根据抗菌活性物质和作用对象将抗菌机理分为三类:直接接触型、溶出-渗透型和催化氧化型.目前的研究表明,三种抗菌机理往往共同存在,相互交错,对其机理分析仍不透彻,因此建议从分子生物学和基因层面,比如细胞修复、蛋白质转换等方面揭示抗菌机理. 相似文献
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采用自制的硅橡胶-沸石杂化优先透乙醇渗透汽化复合膜,利用响应曲面法研究原料液温度和循环流速两个参数对乙醇质量分数为4.05%的乙醇-水体系渗透汽化分离过程的影响.试验表明,温度对膜的通量和分离因子都有显著的影响,温度升高通量增加,而在50℃以下分离因子随温度升高而增加,此后分离因子随温度升高而下降.循环流速的增加会导致通量和分离因子的下降.综合考虑分离因子和通量这两个响应值,利用回归方程求得本试验所采用的渗透汽化复合膜在乙醇一水体系中最优操作条件是:温度59.8℃,循环流速30 L/h,此时总通量和乙醇分离因子分别达到242.8 g/(m2·h)和20.6. 相似文献
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响应面法优化制备巨菌草纳米纤维素及其性能表征 总被引:1,自引:0,他引:1
以巨菌草(pennisetum sinese roxb)为原料,采用酸水解法制备了纳米纤维素(CNC),并应用响应面分析法对影响纳米纤维素得率的3个主要因素即硫酸浓度、温度、时间进行了优化。实验结果表明,利用Design-Expert的Box-behnken中心组合设计建立的二次多项式模型较显著,当硫酸浓度为51%,温度为60℃,时间为120min时,纳米纤维素的得率达到最大值80%。制备的CNC呈棒状,直径约为20~30nm,长度100~200nm;XRD图谱表明CNC的结晶度较巨菌草显著提高;红外光谱表征显示,CNC仍保持纤维素的基本结构。 相似文献
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Isabel F. Almeida Paulo C. Costa M. Fernanda Bahia 《Drug development and industrial pharmacy》2014,40(1):120-125
Topical application of natural antioxidants has proven to be effective in protecting the skin against ultraviolet radiation-mediated oxidative damage. In previous studies, a Castanea sativa leaf ethanol:water (7:3) extract exhibited scavenging activity against different reactive oxygen species that are thought to contribute to oxidative damage in the skin. Its stability was shown to be enhanced in the presence of glycerine, and therefore a glycerine-based formulation with Carbopol 940 and liquid paraffin (LP) was developed as base. In this work, the influence of the glycerine and LP contents on the textural properties of the topical base and on the antioxidant activity of the formulation with C. sativa extract was evaluated using response surface methodology after 30?d storage at 20?°C and 40?°C. The textural analysis was performed in a texturometer, by carrying out a spreadability test. Paretto charts showed that both glycerine and LP contents significantly influenced the textural properties of the formulations (p?0.05). LP presented the major influence. DPPH scavenging activity was not related to any of the studied ingredients. These conclusions were valid both for 20?°C and 40?°C storage. This optimization study provided valuable information to support the development of a semisolid base for C. sativa extract leading to the conclusion that the selection of these ingredients contents can be guided exclusively by the desirable textural properties. 相似文献
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《Advanced Powder Technology》2020,31(6):2348-2356
Particle size and morphology are of high industrial importance due to the fact that product properties and performance can be affected by this factors. For instance, bulk properties, processability and appearance of the final product are given by particle size and shape. In this regard, the optimization of process parameters for particle development is required when targeting formulation of specific product and/or particular properties. Response surface methodology (RSM) was used to optimize the spray drying process for the development of aquasolv lignin particles with desired particle size and morphology. The inlet drying temperature X1: 180–200 °C, atomization pressure X2: 1.3–1.7 bar and feeding rate X3: 65–75 mL min−1 were kept as independent variables while the optimizing responses were: Yield fine of particles with desired particle size and particle size (D50). The quadratic part of the equation and statistical analysis showed substantial effect of the atomizing pressure and feeding rate on the responses and the optimized conditions validated the model. Optimum processing conditions for spray drying of aquasolv lignin were inlet temperature of 173 °C, 1.8 bar atomization pressure and 62 mL/min feeding rate. With this, desired responses of powder were 66% of yield and particle size of D50 < 30 µm were obtained. The experimental values were found to be in agreement with the predicted values indicating the suitability of the model in predicting the particle size and yield of aquasolv lignin. 相似文献
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ABSTRACTH-beta zeolite was modified by the ion exchange method to replace its H+ ions with Ce4+ ions. The catalytic performance of this cerium exchanged beta zeolite was evaluated for vapor phase transalkylation of 1,2,4 TMB (1,2,4 trimethylbenzene) with toluene for the production of xylene in a fixed bed, down-flow reactor. The modified zeolite was found to be highly active for this transalkylation reaction. The response surface methodology (RSM) is used for designing the experiments. The effect of three important reaction parameters viz. temperature, reactant ratio, and space time on response variables (toluene conversion and xylene selectivity) is studied and discussed. All the three selected reaction parameters were found to be significant for the toluene conversion; whereas, xylene selectivity was not much influenced by the temperature. The optimum values of the reaction parameters predicted by the model (temperature: 409.7°C, reactant ratio: 2.024, and space time: 4.451) were validated by an experimental run. The results of the experimental run were in close agreement with the model predicted results. 相似文献
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无机抗菌剂研究发展及新产品开发 总被引:4,自引:0,他引:4
介绍了国内外无机抗菌剂如银系抗菌剂、钛系抗菌剂的研究现状及发展动态 ,着重评述了最新开发的氯制剂类无机抗菌剂 (BMH)的性质、特点 ,讨论了目前无机抗菌剂制备和应用存在的问题 ,并指出了它们可能的发展方向。 相似文献
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铜、银双组分无机抗菌材料的制备和性能研究 总被引:3,自引:1,他引:2
采用溶胶-凝胶法制取白炭黑载体,在一定条件下,将具有杀菌性能的Cu2 、Ag 附着在白炭黑载体上,制得含Cu2 、Ag 双组分杀菌活性成分的无机粉体抗菌材料.运用ICP、粒度分布仪和FTIR等手段对材料中抗菌离子含量、粒度以及抗菌离子与载体的结合方式等进行了表征.并利用菌落计数法对材料的抗菌性能进行研究.结果表明,Cu-Ag双组分抗菌白炭黑中,抗菌离子含量高于单组分抗菌白炭黑;其中,Cu2 是通过离子交换方式结合到白炭黑上的,而Ag 是通过离子交换和吸附两种方式结合到白炭黑上;材料的杀菌率达99%以上;粒径<7μm且均一. 相似文献