抗菌玻璃化学稳定性影响因素研究

采用硼硅酸盐玻璃作为载体,以银离子为有效抗菌成分,制备了载银型可溶性抗菌玻璃材料;着重研究玻璃氧化物组成、热历史、侵蚀液pH值和侵蚀时间对抗菌玻璃化学稳定性的影响。     

二氧化钛/磷灰石纳米抗菌复合材料的研究

为减少生物材料为中心的细菌感染,采用溶胶-凝胶法原位制备了纳米二氧化钛／磷灰石复合材料。对复合材料形貌和组成结构进行了分析,并用复合材料进行了抗菌实验。结果表明二氧化钛与磷灰石在纳米水平上形成了复合材料,其抗菌效果明显。此类具有抗菌性能的纳米复合材料可用于制备多种新型抗菌生物材料。     

细菌纤维素抗菌复合材料的制备和应用

目的 综述细菌纤维素抗菌复合材料在国内外的研究和应用现状,以制备具有优异抗菌性能的细菌纤维素复合材料.方法 总结细菌纤维素抗菌复合材料的抗菌性及其最新合成方式,包括与无机抗菌剂、有机抗菌剂结合或添加抗生素等方式合成细菌纤维素抗菌复合材料,并进一步阐述细菌纤维素抗菌复合材料的应用领域.结论 细菌纤维素复合材料的抗菌性能优异,在医学、食品包装和净水等领域都有较大的应用潜力,有待进一步系统研究.     

纳米铜食品抗菌包装材料的研究进展

目的 介绍纳米铜在食品抗菌包装材料中的研究现状。方法 总结纳米铜食品抗菌包装材料在制备、应用、迁移及安全方面的研究进展,探讨纳米铜抗菌包装材料未来的研究方向。结论 纳米铜的尺寸、形貌、化学组成、分散性、添加量等都会对复合包装材料的力学性能、光学性能、热力学性能等产生影响。纳米铜的加入同时会使复合材料具有抗菌性。纳米铜向食品中的迁移可能会影响食品安全,但目前对纳米铜迁移规律和安全评价的研究不足,需要深入系统地探讨。     

银负载细菌纤维素纳米复合材料的制备及抗菌性能研究

利用细菌纤维素超精细网络结构和高持水率的特点,在细菌纤维素上通过硼氢化钠(NaBH4)还原硝酸银中的Ag+原位生成纳米银颗粒,并对其微观结构等进行表征,同时对银负载细菌纤维素纳米复合膜的抗菌性能和生物相容性进行研究。XRD结果表明纳米银颗粒具有较完善的结晶结构,且银晶体为面心立方结构;XRF检测表明复合材料中含有Ag元素;由UV-Vis可知Ag/BC纳米复合材料在424nm处出现了Ag的吸收峰;从SEM图可看出随着硝酸银浓度的增大,细菌纤维素微纤表面负载的银颗粒增多,粒径大约为50～80nm。抗菌实验结果说明Ag/BC纳米复合材料具有很强的抗菌性能,对大肠杆菌和金黄色葡萄球菌的最大抑菌率分别达到99.4%和98.4%。细胞相容性实验表明,Ag/BC纳米复合材料还具有良好的细胞相容性。因此将其用于抗菌伤口敷料会有广阔的应用前景。     

解决橡胶部件的卫生难题

MilliKen Chemical公司下属的特制弹性体业务部宣布推出了其抗菌热加工橡胶复合材料新产品系列．可以帮助解决容易生长细菌的食品加工、医疗及其他应用场合的卫生难题。此类专利抗菌弹性体称作Elastoguard,在防止细菌、真菌、酵母等在橡胶部件上生长方面特别有效，从而也避免了过去对有机杀灭剂提出的挑战。     

聚合物/层状硅酸盐纳米复合材料阻燃性研究进展

根据层状硅酸盐(黏土)可增强聚合物纳米复合材料阻燃性能的研究进展,本文综述了聚合物/层状硅酸盐纳米复合材料的制备方法,指出熔融插层是一种高效可行、环境友好的制备方法;从硅酸盐在纳米复合材料中产生的阻碍效应、自由基诱导效应,网状结构三个方面详细讨论了层状硅酸盐在纳米复合材料中的阻燃机理;最后,指出目前聚合物/层状硅酸盐纳米复合材料在阻燃研究中尚存在的问题,并对其开发应用前景进行了展望。     

铜负载二氧化钛复合材料的制备及其抗菌性能

以二氧化钛纳米颗粒和硫酸铜溶液为原料,在紫外线灯的照射下进行铜负载二氧化钛纳米带复合材料制备,采用扫描电子显微镜(SEM)、X-射线能谱仪(EDS)、X-射线衍射仪(XRD)、抑菌圈法、细菌比浊法等分析技术研究了所制备负载纳米带复合材料的微观结构及抗菌性能。结果表明,纳米二氧化钛粒子在水热条件下可生长成纳米带,铜均匀负载在纳米带上,从而制备出铜负载二氧化钛纳米带复合材料,负载程度可以通过更改照射时间、硫酸铜浓度等条件进行微调;该负载纳米带复合材料对革兰氏菌有很好的抗菌性能,且负载程度越高,产物抗菌性能越大。     

聚苯胺/银纳米复合材料的形貌对抗菌性能的影响

采用快速混合的方法一步原位合成了不同形貌的聚苯胺/银纳米复合材料。扫描电子显微镜证明,通过改变苯胺与硝酸银的物质的量比可使聚苯胺/银纳米复合材料的形貌由微球到纳米纤维的转变。X射线衍射分析表明,单质银的粒径随着苯胺与硝酸银的物质的量浓度比的减小而增大,聚苯胺仍保持特有的非晶态。紫外-可见光谱分析表明,银纳米粒子与聚苯胺分子间存在相互作用,且银粒子改变了聚苯胺的分子结构。抗菌性实验证明,聚苯胺/银纳米复合材料的形貌对抗菌性能有显著影响,聚苯胺/银纳米纤维有最优异的抗菌性能。     

导电聚合物基抗菌复合材料的合成及生物医用研究进展

以聚吡咯、聚噻吩和聚苯胺为代表的导电聚合物具有优异的导电特性和良好的生物相容性,在生物医学工程、临床医学等领域中有着广泛的应用。由导电聚合物与抗菌剂复合而成的导电聚合物基抗菌复合材料,有助于改善导电聚合物的抗菌性能,降低细菌感染的风险,避免导电聚合物优异的电学性质被细菌生物膜掩盖。本文总结了导电聚合物基抗菌复合材料的研究进展,重点介绍了这类复合材料的抗菌机制、合成策略以及在生物医学工程中的应用现状,最后展望了导电聚合物基抗菌复合材料的发展前景。     

聚合物-粘土纳米复合材料

利用某些层状粘土矿物的吸附性、离子交换性和膨胀性可以将一些聚合物引入到粘土矿物的层间域,形成性能优异的聚合物-粘土矿物纳米复合材料.论述了2:1型层状粘土矿物的结构特点,聚合物-粘土纳米复合材料的合成和表征及粘土片层的表面修饰.从热力学和动力学角度出发,分析了影响嵌入过程的各种因素.展望了聚合物-纳米复合材料的应用前景.     

Morphology development and stability of polypropylene/organoclay nanocomposites

A series of polypropylene (PP)/organoclay nanocomposites with varied concentrations of clay, from 1 to 7 wt%, was successfully prepared via melt intercalation using a PP functionalized with maleic anhydride as compatibilizer. The morphology/property relationships of the nanocomposites were investigated by XRD, TGA and DSC analyses. Two distinct groups of composites, from a quasi-exfoliated to an intercalated/flocculated morphology, were identified. In particular, intercalated/flocculated morphologies were obtained for those composites with an organoclay concentration beyond the threshold (3 wt%), as evidenced by XRD analysis and confirmed by the increase of the glass transition temperature. This last effect was related to the confinement of polymer chains between the silicate layers, generating a reduction of the chain mobility. The variable increase of the thermal stability of the nanocomposites was also likely related to the different degree of exfoliation/intercalation of the samples. The toluene extraction of composites was used as a powerful methodology to distinguish between polymer phases differently interacting with the inorganic surface: composites having a semi-exfoliated structure were split into two fractions having a similar morphology. For those samples having the higher organoclay concentration and intercalated morphology, a toluene-residue fraction was obtained containing almost all the clay present in the pristine composite. Furthermore, in this case the morphological analysis of the residue fraction evidenced a collapse of the inorganic structure compared to that of the unextracted composite. A careful characterization of both soluble and residue fractions is reported and the results are discussed considering the interactions at the interface between the functionalized PP chains and silicate layers and their effects on the organoclay dispersion degree and stability.     

Investigation of surface properties of plasma-modified polyamide 6 and polyamide 6/layered silicate nanocomposites

Polyamide 6 and polyamide 6/layered silicate nanocomposites were treated by oxygen plasma and the resulting surfaces were characterized by X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared-attenuated total reflection (FTIR-ATR). The surface properties were also analyzed by water contact angle measurements and Taber abrasion test. It is found that plasma treatment had different effects on the surfaces of the homopolymer and the polymer nanocomposites. Furthermore, both plasma duration and nanoclay content affect the contact angle and degree of abrasion resistance. In pure polyamide 6, plasma treatment caused the surface to be highly hydrophilic due to the formation of cyclic cis-amide species. Polymer nanocomposites treated with plasma also became more hydrophilic due to oxidation and enrichment of clay at the surface. The abrasion resistance of pure polyamide 6 was increased after exposure to plasma. This is attributed to cross-linking of polymer chains when exposed to plasma. For the polymer nanocomposites, an improvement in abrasion resistance was obtained in samples with low clay content when exposed to plasma for a short time. This is also due to cross-linking as well as the higher abrasion resistance of clay. However, longer exposure to plasma resulted in poorer abrasion resistance due to self-aggregation of clay particles which can be easily removed from the surface. A model was proposed to explain the effect of oxygen plasma on polymer nanocomposite surface.     

聚合物-层状硅酸盐纳米复合材料中的计算机模拟研究进展

聚合物-层状硅酸盐纳米复合材料是近20年来的研究热点,而计算机模拟已经逐渐发展为科学研究的重要手段。文中系统综述了计算机模拟在聚合物-层状硅酸盐纳米复合材料机理研究中的应用,介绍了适用于此类材料的模拟方法和力场,并重点论述了计算机模拟用于研究有机粘土的结构、纳米复合材料中各个组分间的相互作用,以及对纳米复合材料力学性能预测的研究现状。最后指出了本领域存在的问题并对前景进行了展望。     

A biomimetic approach to enhancing interfacial interactions: polydopamine-coated clay as reinforcement for epoxy resin

A facile biomimetic method was developed to enhance the interfacial interaction in polymer-layered silicate nanocomposites. By mimicking mussel adhesive proteins, a monolayer of polydopamine was constructed on clay surface by a controllable coating method. The modified clay (D-clay) was incorporated into an epoxy resin, it is found that the strong interfacial interactions brought by the polydopamine benefits not only the dispersion of the D-clay in the epoxy but also the effective interfacial stress transfer, leading to greatly improved thermomechanical properties at very low inorganic loadings. Rheological and infrared spectroscopic studies show that the interfacial interactions between the D-clay and epoxy are dominated by the hydrogen bonds between the catechol-enriched polydopamine and the epoxy.     

植酸-金属离子螯合物改性层状黏土及其在聚己内酯中的增强与抗菌效应研究

基于植酸(PA)优异的螯合能力,利用Ag^+,Cu^2+,Fe^3+和Zn^2+4种金属离子与PA发生螯合作用并沉积吸附在层状双羟基复合金属氧化物(LDHs)表面,形成核-壳结构,以达到改善层状黏土与聚合物基体之间界面相容性的目的。制备出不同金属离子负载的表面包覆改性LDHs(LDHs@PA-M),深入研究LDHs@PA-M在不同金属离子负载下的微观形貌,并将其应用在聚己内酯(PCL)的增强改性中。结果表明,PA能够与Ag^+和Cu^2+在LDHs表面形成稳定、均匀的纳米包覆层。利用金属Ag^+和Cu^2+优异的抗菌活性,LDHs@PA-Ag^+和LDHs@PA-Cu^2+对大肠杆菌(E.coli)的抗菌率均超过99.99%。相比于纯的PCL,LDHs@PA-Cu^2+/PCL纳米复合材料(LDHs@PA-Cu^2+的质量分数为1%)的拉伸强度和断裂伸长率分别提高了30.7%和33.3%,达到了40.9 MPa和816%,力学性能增强效果最为显著。LDHs@PA-Cu^2+/PCL和LDHs@PA-Ag^+/PCL纳米复合材料对E.coli的抗菌率均达到99.99%,表现出优异的抗菌活性,拓展了层状黏土/生物基高分子复合材料在活性包装领域的应用。     

Polylactide (PLA)-clay nanocomposites prepared by melt compounding in the presence of a chain extender

Polylactide-layered silicate nanocomposites with and without a chain extender were prepared by melt mixing using a twin-screw extruder. An organo-modified clay, Cloisite® 30B, and a chain extender Joncryl®-ADR 4368F were employed in this study. The effect of the chain extender and processing conditions on the properties of the PLA-clay nanocomposites were investigated for different strategies of mixing. The resulting nanocomposites were characterized by X-ray diffraction (XRD), while their morphology was observed by SEM and TEM. The incorporation of the chain extender could enhance the degree of clay dispersion provided that it is judiciously added to the nanocomposite. The corresponding results revealed that the Joncryl-based nanocomposites, where nanoclay platelets were well-dispersed, exhibited a significantly reduced permeability as compared to others. The mechanical properties of the neat PLA, the PLA and Joncryl-based nanocomposites were also examined. The increased molecular weight in Joncryl-based nanocomposites caused a significant increase in the modulus, drawability and toughness of the samples.     

Characterization of poly(ethylene-<Emphasis Type="Italic">co</Emphasis>-vinyl acetate-<Emphasis Type="Italic">co</Emphasis>-carbon monoxide)/layered silicate clay hybrids obtained by melt mixing

In recent times, polymer-layered silicate nanocomposites have drawn a great deal of attention because they often exhibit tremendous improvements in material properties compared with virgin polymers or conventional micro- or macro-composites. In the present study, nanocomposites were developed from organically modified clay and poly(ethylene-co-vinyl acetate-co-carbon monoxide) by melt mixing. FTIR spectroscopy reveals that the interaction between the organoclay and EVACO is thermodynamically favored. High resolution wide angle X-ray diffraction and transmission electron microscopy were used to study the morphology of the nanocomposites. Elemental mapping by scanning electron microscopy indicates good dispersion and distribution of the nanoclay in EVACO matrix. The mechanical properties of the nanocomposites are optimum at a clay loading of 3%.     

Clay-based polymer nanocomposites: research and commercial development

This paper reviews the recent research and development of clay-based polymer nanocomposites. Clay minerals, due to their unique layered structure, rich intercalation chemistry and availability at low cost, are promising nanoparticle reinforcements for polymers to manufacture low-cost, lightweight and high performance nanocomposites. We introduce briefly the structure, properties and surface modification of clay minerals, followed by the processing and characterization techniques of polymer nanocomposites. The enhanced and novel properties of such nanocomposites are then discussed, including mechanical, thermal, barrier, electrical conductivity, biodegradability among others. In addition, their available commercial and potential applications in automotive, packaging, coating and pigment, electrical materials, and in particular biomedical fields are highlighted. Finally, the challenges for the future are discussed in terms of processing, characterization and the mechanisms governing the behaviour of these advanced materials.     

聚合物─层状粘土矿物纳米复合材料的合成与表征

利用某些层状粘土矿物的吸附性、离子交换性和膨胀性，可以将一些聚合物单体嵌入到粘土矿物的层间，接着在受约束的二维层间域进行聚合，或者是将聚合物直接嵌入到它们的层间域，形成性能优异的聚合物—层状粘土矿物纳米复合材料和功能材料。本文简要地论述了2：1型层状粘土矿物的结构特点，聚合物—层状粘土矿物纳米复合材料的合成、表征及其性能。