再生纤维素/壳聚糖/银纳米线抗菌复合膜制备及性能

以1-丁基-3甲基咪唑氯盐（[Bmim]Cl）为溶剂体系，通过微晶纤维素（MCC）溶解再生制备基膜，壳聚糖（CS）、银纳米线（AgNW）共混液包覆方法制备抗菌复合膜，通过FTIR、XRD、SEM和热重分析对复合膜的形貌和结构进行表征及对力学、光学、阻隔、抑菌等性能测试分析。结果表明，壳聚糖和银纳米线成功复合于纤维素基膜，与再生纤维素膜相比，当AgNW质量分数为0.5%时，复合膜的拉伸强度提升了12.2%，透光率保持在89.82%，氧气透过率下降了86.7%，且对大肠杆菌具有良好的抑制作用，制备出一种力学性能、光学性能、阻隔性能、抗菌性能优异的可降解纤维素/壳聚糖/银纳米线抗菌复合膜。     

壳聚糖-银纳米微粒表面修饰木纤维的制备及抗菌性能研究

以液相还原法制备了壳聚糖-银纳米微粒（CS-Ag NPs）,并通过γ-巯丙基三甲氧基硅烷作为硅烷偶联剂将其修饰到木纤维表面,获得了具有抗菌性能的CS-Ag NPs表面修饰木纤维。采用透射电子显微镜研究了CS-Ag NPs的形貌;以傅里叶变换红外光谱、扫描电子显微镜、热重分析仪等分析手段对CS-Ag NPs表面修饰的木纤维进行了结构形貌以及热稳定性的分析,并讨论了其吸水性能。结果表明表面修饰后的木纤维接枝率为3.06%,具有高热稳定性及低吸水性。通过琼脂板计数法测试了CS-Ag NPs表面修饰前后的木纤维对耐甲氧西林金黄色葡萄球菌、革兰氏阳性菌金黄色葡萄球菌、蜡状芽庖杆菌以及革兰氏阴性菌大肠埃希氏菌的抗菌效果,结果显示表面修饰后的木纤维对实验菌种的抑菌率都在99.0%以上。此外,还研究了未处理、PVP-Ag NPs以及CS-Ag NPs表面处理的木纤维板的抗菌性能,结果表明,在湿热环境下,CS-Ag NPs表面处理的木纤维板到第8天时仍没有霉菌长出,而未处理的木纤维板和传统抗菌剂银纳米微粒处理的木纤维板到第5天时就开始长霉菌,由此可以看出表面修饰CS-Ag NPs的木纤维板具有更好的抗菌效果。     

空气除湿用抗菌透湿复合膜的制备

为提高膜式全热交换器的除湿性能并使膜具备抗菌性能,以Li Cl为亲水添加剂,Ag NO3为抗菌剂,添加到聚乙烯醇（PVA）水溶液中制成铸膜液,以聚丙烯（PP）膜为支撑层,制备了一种抗菌透湿复合膜。搭建了薄膜透湿性测量平台,测试了复合膜的水蒸气透过量,对复合膜的抗菌性进行了检测。结果表明,复合膜的水蒸气透过量随Li Cl含量的增加而增加,Li Cl含量为5%的复合膜是不含Li Cl复合膜的1.79倍,是商用纸膜的2.67倍。加入Ag NO3后薄膜的透湿性没有明显变化,抗菌实验结果显示,复合膜对表皮葡萄球菌、大肠杆菌有抗菌作用,对表皮葡萄球菌的抗菌作用更强。     

黄原胶和纳米二氧化硅对无氟泡沫性能的影响

纳米粒子、高分子聚合物稳定泡沫的独特优势使其成为解决泡沫稳定性的研究热点。本文探索了亲水二氧化硅纳米颗粒（NPs）、高分子聚合物黄原胶（XG）对无氟泡沫分散液的发泡性能、泡沫稳定性及铺展性等泡沫性能的影响。研究结果表明，NPs和XG对泡沫稳定性有显著影响。与NPs相比，添加XG有助于增强泡沫稳定性，但对泡沫分散液发泡性能有抑制。NPs添加量为3.0%（质量分数）时，泡沫分散液的发泡能力得到提高。同时添加NPs和XG时，控制二者添加浓度可在稳定泡沫过程中产生协同效应。在铺展过程中，加入NPs、XG后泡沫分散液黏度增加，使泡沫分散液在汽油表面的铺展有不同程度的减缓，但对灭火产生不利影响。     

鱼鳞明胶/壳聚糖/薰衣草精油抗菌复合膜制备及性能

以鱼鳞明胶(SG)和壳聚糖(CS)为原料,薰衣草精油(LEO)为抗菌剂,通过共混法制备抗菌复合膜,通过FTIR、XRD、SEM和热重分析对复合膜的形貌和结构进行表征及对力学、光学、阻隔、抑菌等性能测试分析。结果表明,LEO与SG/CS基膜较好复合,与SG/CS基膜相比,当LEO添加量为1%时,复合膜具有良好的力学强度(26.36 MPa),断裂伸长率提升了12.96%；透明度有所下降,透光率为70.50%；耐水性能和水蒸气阻隔性能显著增强,含水率、水溶性和水蒸汽透过率分别下降了22.48%、30.49%和26.03%；DPPH自由基清除率提高了247.88%,抗氧化性显著提高；同时对大肠杆菌和金黄色葡萄球菌具有良好的抑菌作用。     

纳米纤维素/壳聚糖/明胶复合膜的制备及其性能研究

以明胶（Gel）、壳聚糖（CS）、纳米纤维素（NCC）为原料,采用溶液共混法制备了不同NCC和CS质量比的纳米纤维素/壳聚糖/明胶复合膜。采用紫外-可见分光光度计、扫描电镜（SEM）、红外光谱仪（FT-IR）、X射线衍射仪（XRD）、热分析仪（TGA）和质构仪对所制备复合膜的透光性能、显微结构、化学结构、晶体结构、热学性能和力学性能进行了分析。结果表明：纳米纤维素、壳聚糖、明胶之间形成相互作用较强的网络结构。复合膜表面光滑,分散均匀,具有良好的相容性。随着纳米纤维素含量的增加,复合膜透光率呈下降的趋势。与壳聚糖膜相比,复合膜的热稳定性显著提高。当纳米纤维素与壳聚糖质量比为7：1时,复合膜拉伸强度最高可达到33 MPa,断裂伸长率可达到14.9%,吸水率最大值可达到341%。     

纳米抗菌粉体材料的制备与应用研究

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，持久和耐热等特点，在日用陶瓷釉中添加量为2.0wt%时，抗菌陶瓷餐具的抗菌率可以达到99.9%以上。     

纳米TiO2增强阴离子导电膜中碱性离子液体的稳定性研究

首先，以N-甲基吡咯烷为原料，通过两步法合成碱性甲基吡咯烷离子液体（[DMPy]OH）。然后，通过物理掺杂方式在聚乙烯醇（PVA）膜基质中引入[DMPy]OH碱性离子液体和纳米二氧化钛（TiO2），最后引入戊二醛（GA）交联PVA，制得PVA-[DMPy][OH]-TiO2复合膜。利用纳米二氧化钛（Nano-TiO2）表面分布的未配位饱和的Ti4+、O2-与[DMPy]OH中阴阳离子间的自组装效应，以及戊二醛（GA）交联PVA形成半互穿结构来降低膜内碱性离子液体的流失率，增加膜内“阳离子活性点位”数量，加快OH-的迁移速率，提高电导率。借助X射线衍射(XRD)和Mapping测试证实了Nano-TiO2和[DMPy]OH间自组装作用的存在，同时对复合膜的机械性能、热稳定性能、电导率、耐碱性等指标进行测试。结果表明，该系列复合膜，形貌平整、均一；当离子液体添加量为25wt%，Nano-TiO2添加量为1wt%时，80℃下PVA-[DMPy][OH]-TiO2复合膜的电导率为2.78×10-3 S.cm-1，室温下浸渍于水中12h后，离子液体流失率为23.2%；与未添加Nano-TiO2的PVA-[DMPy][OH]膜相比，电导率提高了19.4%，离子液体流失率降幅约为34.3%；室温下，3M KOH中耐碱性测试120h后，电导率和初始值相比并无明显变化，表现出优异的耐碱稳定性。热稳定性测试结果表明，该膜分解温度高于200℃，具有良好的热稳定性。     

纤维素基有机-无机杂化复合膜的制备及其吸附性能

以羧甲基纤维素（CMC）为原料，经高碘酸钠选择性氧化制备双醛基羧甲基纤维素（DCMC），与明胶通过“席夫碱键”化学交联并掺杂海泡石构筑纤维素基有机-无机杂化复合膜。超声波辅助处理能够有效促进微纤维状海泡石在双醛羧甲基纤维素/明胶溶解体系中的均匀分散，同时产生氢键缔合作用，所得混合液经真空干燥成膜。采用扫描电子显微镜（SEM）、傅里叶变换红外光谱分析仪（FTIR）、热分析仪（TGA）、质构仪对DCMC/明胶/海泡石复合薄膜形貌特征、官能团、热稳定性和力学性能进行表征与分析。结果表明，加入海泡石后复合薄膜力学性能显著提高，当海泡石添加量为0.5g时，拉伸应力和断裂伸长率同时达到最佳效果。复合膜具有良好的热稳定性，显著失重温度在300~350℃范围内。吸附实验表明该复合薄膜材料具备良好的染料吸附性能，对于选定的3种染料（亚甲基蓝、孔雀石绿、藏红T），复合膜吸附量均随海泡石含量的增加而增大，当海泡石添加量大于0.5g时吸附量均超过200mg/g，脱附实验表明该杂化膜可经酸处理解吸再生，有较好的重复利用率。该生物质基有机-无机杂化复合薄膜原料来源丰富，生物可降解，在生物医用和污染防治方面具有潜在应用价值。     

京尼平交联明胶蛋白与壳聚糖抗菌膜的制备及性能研究

以壳聚糖和明胶两种化合物为原料,并以天然的京尼平为交联剂,制备复合抗菌膜。通过单因素和正交设计试验探讨成膜材料比例、甘油添加量、京尼平添加量对明胶和壳聚糖复合抗菌膜性能的影响,并对膜材料的抗菌性能等进行研究。结果表明:京尼平对于改善壳聚糖抗菌复合膜的拉伸性能和阻隔性能具有很好的效果。膜制备的最佳工艺条件是明胶与壳聚糖配比为6∶4,甘油添加量2%,京尼平添加量0.6%,此时膜的拉伸强度(TS) 1.86 MPa,断裂伸长率(E)30.46%,透光率(T) 54%,水蒸气透过率(WVP)1.22%,大肠杆菌和金黄色葡萄球菌的抑菌性分别为18.68 mm和16.25 mm。在此条件下制得的壳聚糖复合膜具有良好的阻隔性能、抗拉强度、致密性和抑菌性能,可用于食品保鲜和抗菌内外包装的使用。     

Preparation and Characterization of Gelatin Nanofibers Containing Silver Nanoparticles

Ag nanoparticles (NPs) were synthesized in formic acid aqueous solutions through chemical reduction. Formic acid was used for a reducing agent of Ag precursor and solvent of gelatin. Silver acetate, silver tetrafluoroborate, silver nitrate, and silver phosphate were used as Ag precursors. Ag⁺ ions were reduced into Ag NPs by formic acid. The formation of Ag NPs was characterized by a UV-Vis spectrophotometer. Ag NPs were quickly generated within a few minutes in silver nitrate (AgNO₃)/formic acid solution. As the water content of formic acid aqueous solution increased, more Ag NPs were generated, at a higher rate and with greater size. When gelatin was added to the AgNO₃/formic acid solution, the Ag NPs were stabilized, resulting in smaller particles. Moreover, gelatin limits further aggregation of Ag NPs, which were effectively dispersed in solution. The amount of Ag NPs formed increased with increasing concentration of AgNO₃ and aging time. Gelatin nanofibers containing Ag NPs were fabricated by electrospinning. The average diameters of gelatin nanofibers were 166.52 ± 32.72 nm, but these decreased with the addition of AgNO₃. The average diameters of the Ag NPs in gelatin nanofibers ranged between 13 and 25 nm, which was confirmed by transmission electron microscopy (TEM).     

The effect of Ag,ZnO, and CuO nanoparticles on the properties of the compatibilized polyethylene/thermoplastic starch blend films

In this study, the effects of Ag, ZnO, and CuO nanoparticles (NPs) on the mechanical, thermal, and biodegradability properties of the compatibilized polyethylene (PE)/thermoplastic starch (TPS) blends were investigated. Polyethylene-grafted maleic anhydride (PE-g-MA) was used as the compatibilizer. The compatibilized PE/TPS blends with different NPs were prepared by melt mixing method in a laboratory scale extruder and then pressurized in the press machine. The use of ZnO NP together with the compatibilizer in PE/TPS-based films significantly increased the tensile stress values. The use of different type NPs did not cause any significant change in the thermal stability of PE/TPS-based films. However, the effects of NPs were observed on the TPS degradation steps. The prepared films with different NPs showed an antibacterial activity between 60% and 70%. The highest crystallinity value was obtained in Ag NP containing films, among others. According to scanning electron microscopy analysis, better distribution was observed for ZnO and Ag NPs than CuO NP. In general, it can be said that the addition of NPs to PE/TPS-based blends significantly reduces the partial biodegradability of the resulting films.     

Facile Deposition of Silver Nanoparticles on Photonic Cellulose Nanocrystals Films: A Study on Solvent Stability and Post Antibacterial Activity

Cellulose nanocrystals (CNCs) incorporated with silver nanoparticles (AgNPs) photonic films have drawn considerable attention due to their plasmonic chiroptical activity. However, the exploitation of some fundamental properties for practical use such as the affinity analysis of metal nanoparticles attached to the surface of photonic films according to the solvent compatibility and antibacterial activity under physical conditions has yet not been studied. Hence, a facile process of in situ deposition of AgNPs into the chiral structure of CNC films is proposed. CNC photonic films, cross-linked by glutaraldehyde are prepared. This interaction generated the solvents-stable photonic film with a considerable amount of unreacted aldehyde functional groups that facilitates the reduction of Ag salt to AgNPs. The formed AgNPs in the photonic films show excellent stability over immersion in various polar and non-polar solvents. The post-solvent treated photonic films display excellent contact-based antibacterial behavior against gram-negative Escherichia coli.     

Enhanced antibacterial activity of bimetallic gold-silver core-shell nanoparticles at low silver concentration

Herein we report the development of bimetallic Au@Ag core-shell nanoparticles (NPs) where gold nanoparticles (Au NPs) served as the seeds for continuous deposition of silver atoms on its surface. The core-shell structure and morphology were examined by UV-Vis spectroscopy, transmission electron microscopy (TEM), energy dispersive X-ray (EDX) analysis and X-ray diffraction (XRD). The core-shell NPs showed antibacterial activity against both gram negative (Escherichia coli and Pseudomonas aeruginosa) and gram positive (Enterococcus faecalis and Pediococcus acidilactici) bacteria at low concentration of silver present in the shell, with more efficacy against gram negative bacteria. TEM and flow cytometric studies showed that the core-shell NPs attached to the bacterial surface and caused membrane damage leading to cell death. The enhanced antibacterial properties of Au@Ag core-shell NPs was possibly due to the more active silver atoms in the shell surrounding gold core due to high surface free energy of the surface Ag atoms owing to shell thinness in the bimetallic NP structure.     

Preparation and property of antibacterial filter membrane by coaxial electro-spraying/electrospinning technology

Herein, a novel technology named coaxial electro-spraying/electrospinning was successfully introduced, which can simultaneously prepare nanofibers and nanoparticles. First, the device contains an outer nozzle and an inner nozzle, which combine electrospinning with electro-spraying technology. Then, the polyamide 6 (PA6) was spun to prepare the nanofibers from the inner nozzle, and the silver nanoparticles (Ag NPs) into the PA6 solution were sprayed to prepare the nanoparticles from the outer nozzle. PA6 nanofibers (NFs)/Ag nanoparticles (NPs) antibacterial composite membranes for the filtration of fine particulate pollutants were successfully prepared using coaxial electro-spraying/electrospinning. The microstructure, physical properties, and antibacterial properties of the composite membrane were investigated. The results show that Ag NPs are successfully loaded in situ onto PA6 NFs of approximately 100 nm to form a three-dimensional (3D) structure. The filtration efficiency of the 3D structured filtration membrane reaches 90.98%, compared to only 12.78% for the melt-blown cloth mask filter material when tested with polystyrene microspheres (PS) of 200 nm. The contact angle of the composite membrane decreased from 145.47° to 44.11°, indicating a significant improvement in the hydrophilicity of the membrane. Furthermore, depositing Ag on the surface fibers resulted in an impressive antibacterial rate of 99.75% against Penicillium.     

Synergistic effect of graphene oxide‐silver nanofillers on engineering performances of polyelectrolyte complex nanofiber membranes

The poor mechanical and antibacterial performance has become a big hurdle for extending the application of polyelectrolyte complex (PEC) nanofibers in various fields. In this study, chitosan/gelatin (CG) composite nanofiber system was used for portraying the synergistic enhancement of mechanical and antibacterial properties of PEC nanofiber membranes by inclusion of graphene oxide‐silver (GO‐Ag) nanofillers. In particular, the introduction of 1.5 wt % GO‐Ag has raised the elastic modulus and tensile strength of CG nanofiber membrane by 105% and 488%, respectively, which are partially attributed to the alleviated restacking of graphene sheets by the anchored AgNPs. Meanwhile, the diameters of inhibition zone against Escherichia coli and Staphylococcus aureus on LB‐agar plates induced by GO‐Ag/CG nanofiber membranes are increased by 80.5% and 50.1%, respectively, compared to that by CG membrane. The synergistic improvement of antimicrobial performance of GO‐Ag/CG may be related to the accumulation of microorganisms induced by GO. In summary, the incorporation of GO‐Ag composite nanofillers has emerged as an effective strategy for engineering PEC nanofiber membranes for potential applications in nanomedicine and tissue engineering. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46238.     

Antibacterial activities of novel nanocomposite biofilms of chitosan/phosphoramide/Ag NPs

Novel nanocomposite films of chitosan/phosphoramide/Ag NPs were prepared containing 1–5% of silver nanoparticles. The Ag NPs were synthesized according to the citrate reduction method. The XRD and SEM analysis of Ag NPs, chitosan (CS), phosphoramide (Ph), CS/Ph, CS/Ag NPs films and the nanocomposite films 1–5 containing CS/Ph/1–5% Ag NPs were investigated. The in vitro antibacterial activities were evaluated against four bacteria including two Gram‐positive Staphylococcus aureus (S. aureus), Bacillus cereus (B. cereus) and two Gram‐negative Escherchia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa) bacteria. Results revealed greater antibacterial effects of the films against Gram‐positive bacteria. Also, nanocomposite films containing higher percent of Ag NPs showed more antibacterial activities. POLYM. COMPOS. 36:454–466, 2015. © 2014 Society of Plastics Engineers     

Electrospun antibacterial nylon nanofibers through in situ synthesis of nanosilver: preparation and characteristics

A new method for production of nylon nanofibers with antibacterial properties containing silver nanoparticles (nylon nanofibers/Ag NPs) is introduced via in situ synthesis of nano-silver by reduction of silver nitrate in the polymer solution prior to electrospinning. The properties of the electrospinning solutions and the structures of the electrospun fibers were studied using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDAX), UV?Cvis spectrophotometer and reflection spectrophotometer. Further, the antibacterial properties of the nanofibers were investigated against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive) bacteria. Interestingly, an antibacterial properties has been found on nylon 6 nanofibers while the nylon nanofibers/Ag NPs showed excellent antibacterial activities against both tested bacteria. The produced nylon nanofibers/Ag NPs can be a good candidate for biomedical applications, water and air filtration.     

Green Synthesis and Characterization of Silver/Chitosan/Polyethylene Glycol Nanocomposites without any Reducing Agent

This paper presents the green synthesis of silver nanoparticles (Ag NPs) in aqueous medium. This method was performed by reducing AgNO(3) in different stirring times of reaction at a moderate temperature using green agents, chitosan (Cts) and polyethylene glycol (PEG). In this work, silver nitrate (AgNO(3)) was used as the silver precursor while Cts and PEG were used as the solid support and polymeric stabilizer. The properties of Ag/Cts/PEG nanocomposites (NCs) were studied under different stirring times of reaction. The developed Ag/Cts/PEG NCs were then characterized by the ultraviolet-visible (UV-Vis) spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy.     

A straightforward preparation and characterization of novel poly(vinyl alcohol)/organoclay/silver tricomponent nanocomposite films

In the present investigation, novel poly(vinyl alcohol)/organoclay/silver (PVA/OMMT/Ag) tricomponent nanocomposite (NC) films with different compositions were prepared by solution intercalation method under ultrasonic irradiation process. The NC films were obtained by mixing a colloidal solution consisting of Ag nanoparticles (NPs) (3, 5, 7 and 9 wt%) with a water solution of PVA and OMMT (10 wt%) via solution casting method. The scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction, Fourier transform infrared spectroscopy, and thermogravimetric analysis (TGA) were utilized to characterize the morphology and properties of the PVA/OMMT/Ag NC films. TGA confirmed that the heat stability of the nanocomposite was improved. The enhancement in the thermal properties of the hybrid materials was due to strong hydrogen bonding between OH groups of PVA, free acid functionalized groups of OMMT, and the Ag NPs. SEM and TEM results also showed that the OMMT and Ag NPs were dispersed homogeneously in the PVA matrix on nanoscale.