无机抗菌粉体中银价态与抗菌性能研究

以SiO2为基体，Ag^ 作为主要抗菌成分的无机抗菌剂粉体，控制银离子的含量为n（Ag）：n（Si）=0.0286时，在无机抗菌剂中分别引入摩尔分数约30％的Al^3 或60％的Zn^2 ，用于稳定无机抗菌剂中银价态，制备出不变色的无机抗菌粉末。利用XPS技术分析和抗菌性能测试，研究不同温度下抗菌粉体的抗菌性能和银价态关系，揭示含银无机抗菌剂银价态和抗菌性能关系及其机制。研究发现：银离子的价态对粉体的抗菌性能影响很大，当银离子以AgO状态存在时，粉体的抗菌性能较好，若为银单质存在，则抗菌性能下降。Zn^2 的加入，有利于稳定高温时抗菌粉体中的银离子仍以银的氧化物状态存在。     

抗菌聚丙烯母粒的制备及表征

抗菌剂在PP基体中的分散相容性明显影响PP抗菌材料的力学性能和抗菌性能。通过力学性能测试、扫描电子显微镜(SEM)测试及抗菌性能测试,考查了载银和载银铜抗菌PP母粒的力学性能、无机抗菌剂在PP基体中分散情况以及抗菌母粒的抗菌性能。结果表明,无机抗菌剂在PP基体中分散均匀,加入无机抗菌剂后PP共混材料的拉伸强度和冲击强度无明显变化。通过抗菌性能测试表明,银离子具有较强的杀菌能力,可以通过缓释技术使其达到长效杀菌的目的。     

载银麦饭石抗菌剂的制备及性能研究

以325目的麦饭石为载体,在一定条件下（Ag^＋ 浓度、搅拌温度、搅拌时间等）通过液相离子交换反应,制备得到载银麦饭石抗菌剂。运用ICP和XED等现代技术对材料中银离子含量以及银离子与载体的结合方式进行了分析,并对材料的抗菌性、抗菌耐久性和安全性能进行研究。结果表明：在搅拌时间是6h,搅拌温度是60℃,Ag^＋浓度是0．10mol／L时,制备麦饭石抗菌剂具有优异抗菌性和耐久性以及良好的安全性。究其原因主要在于该抗菌剂中Ag大多数以离子形式存在,赋予该抗菌剂良好的抗菌性;而且Ag^＋能从载体上持久地释放出来,从而保持了抗菌剂持久的抗菌能力。     

银-钬抗菌白炭黑的合成

本研究采用溶胶-凝胶法合成了一种新型无机抗菌材料-银-钬抗菌白炭黑.与只含有银的抗菌白炭黑相比,这种新型抗菌材料具有更显著的杀菌效果.其对大肠杆菌的杀菌率能达99％以上.通过研究银离子浓度、钬离子浓度和反应时间对杀菌率的影响,得到较理想的制备条件是,银离子浓度0.09 mol·L-1,钬离子浓度0.003 mol·L-1,反应时间2.5h.通过对FTIR图谱的分析,可知银离子和钬离子的添加几乎未改变白炭黑的结构.另外XRD图谱显示该材料为无定形态.     

聚乳酸基抗菌材料研究现状

简述了聚乳酸(PLA)基抗菌材料的研究现状,包括二氧化钛系列、银离子系列等无机抗菌剂型,合成有机物系列、天然有机物系列等有机抗菌剂型,以及有机无机复合抗菌剂型。比较了不同抗菌剂与PLA作用的综合抗菌效果,分析了各类抗菌剂的优缺点,并对PLA基抗菌材料的进一步发展提出了展望,指出在PLA材料自身条件下进行调控以达到抗菌的目的是今后PLA抗菌材料的重要发展方向。     

铜型抗菌层状硅酸盐的合成研究

采用液相离子交换法,将抗菌铜离子与钠基蒙脱石合成抗菌层状硅酸盐材料。研究了溶液浓度、pH值及反应时间等对合成抗菌材料中铜离子含量的影响。通过正交试验确定合成铜型抗菌层状硅酸盐的较佳反应条件为:CuCl2溶液的浓度0 1mol·L-1,在自然pH值下反应约1h。实验还测定抗菌层状硅酸盐的抗菌性能:铜型抗菌层状硅酸盐抗大肠杆菌、金黄色葡萄球菌等细菌性能良好,但抗霉菌性能一般。     

羟基磷灰石抗菌剂的研究

采用正交设计方法,以羟基磷灰石作为载体,银离子和铈离子作为抗菌离子,采用离子交换方法制备羟基磷灰石抗菌剂,考察了硝酸银浓度、反应时间、反应温度和硝酸铈浓度等因素.运用X射线衍射谱研究了影响羟基磷灰石抗菌剂的微观结构;运用抑菌圈法表征所制备的抗菌剂的抗菌性能.研究表明:硝酸银浓度为0.2 mol/L、反应温度为30℃、反应时间为3 h和硝酸铈浓度为0.01 mol/L时对羟基磷灰石抗菌效果最好.     

载铜无机抗菌剂的制备及性能

以天然麦饭石为载体、铜离子为抗菌离子,在一定条件下通过液相离子交换反应,制备载铜麦饭石抗菌剂.运用ICP和XRD等现代分析方法对抗菌剂中银离子的含量以及银离子与载体的结合方式进行了分析,并对其抗菌性、耐久性和安全性能进行研究.结果表明,在Cu2+浓度是0.1 mol·L-1,搅拌时间是4 h,反应温度是60 ℃时,制备的麦饭石抗菌剂具有优异抗菌性、耐久性和安全性.究其原因主要在于Cu2+能从载体上缓慢地释放出来,与细菌细胞作用,杀灭细菌,从而赋予该抗菌剂良好的、持久的抗菌能力.     

海泡石载银/铜复合抗菌剂的制备与性能研究

以活化后的海泡石作为载体,通过离子交换方法,分别合成了载银、载银/铜以及银/锌等复合海泡石抗菌粉体。对各种抗菌剂的杀菌能力进行了评价,结合实际杀菌效果分析,发现复合抗菌剂要比单一的效果好,并且以负载银/铜的微米级复合抗菌剂抗菌性能最好。同时对抗菌剂进行了XRD、SEM与EDS等分析。     

离子吸附法制备载银Al_2O_3抗菌剂的研究

以Al2O3为载体,采用离子吸附法制备了载银Al2O3抗菌剂,研究了其制备工艺如银离子掺量、反应温度、煅烧温度等对抗菌性能的影响,找出了最佳制备方法,并利用XRD结合离子溶出浓度的测试分析了其高温抗菌性能的变化。实验结果表明,采用离子吸附法制备的载银Al2O3抗菌剂具有优异的抗菌性能,其最佳制备工艺是银离子掺量为6%,搅拌时间为6h,煅烧温度为1000℃,其抑菌圈的宽度可以达到3.5mm。     

Effect of potassium and silver ion-exchange on the strengthening effect and properties of aluminosilicate glass

In this work, the aluminosilicate glass was subjected to ion-exchange using the KNO₃-AgCl mixed molten salt in order to strengthen the glass while imparting antimicrobial properties. The concentration distribution of K⁺ ions and Ag⁺ ions of the ion-exchanged glasses was characterized by EDS, the effects of ion-exchange temperature (460-500 °C), ion-exchange time (0.5-3 h) and AgCl concentration (0–2.5 wt%) in the mixed molten salt on the strengthening effect and properties of the glass were investigated. The results showed that Ag⁺-Na⁺ ion-exchange, K⁺-Na⁺ ion-exchange existed simultaneously, and Ag⁺-Na⁺ ion-exchange occurred preferentially. Due to the presence of metallic silver, the appearance of the Ag⁺ ion-exchanged glass was light yellow and its transmittance showed a decrease. The surface compressive stress trended up and then down with increasing temperature and time because of the stress relaxation effect. The Vickers hardness of ion-exchanged glass increased by 15%, and the densities and chemical stability were also increased. Ions leaching experiments showed that the Ag⁺ ions release concentration of silver-loaded glass in aqueous environment can reach the bactericidal level. It has been shown that ion-exchange of glass in KNO₃-AgCl mixed molten salts allowed the glass to be strengthened and incorporated with antimicrobial active ions, its chemical stability was improved, too.     

Formulation of epoxy–polyester powder coatings containing silver-modified nanoclays and evaluation of their antimicrobial properties

Current interest in antimicrobial coatings is driven by an urgent need for more effective strategies to control microbial infection. In this study, antimicrobial nanoclays were prepared by ion-exchange of sodium montmorillonite (MMT) with silver ions which have been previously reported to exhibit biocidal activity. The extent of ion-exchange achieved was estimated by X-ray photoelectron spectroscopy. The silver-modified nanoclay (AgMMT) fully inhibited growth of Gram-negative bacterium Escherichia coli DH5α (E. coli) over 24 h; annealing AgMMT under typical conditions used to prepare polymer composites did not reduce its antimicrobial efficacy. However, powder coatings of AgMMT dispersed in epoxy/polyester resin exhibited no antimicrobial effect on E. coli. This is believed to be caused by poor wetting of the polymer coating, which restricted the diffusion of silver ions from the coating.     

Activity of antibacterial compounds immobilised on montmorillonite

The activities of antibacterial compounds, such as cetylpyridinium (CP), cetyltrimethylammonium (CTA), silver ions and metallic silver, immobilised on montmorillonite (MMT), were tested in Escherichia coli and Enterococcus faecium bacteria. The results of bacterial growth tests were confirmed by determination of the minimum inhibition concentrations (MICs). Unlike CP and CTA, the intercalated silver ions were easily released from MMT by ion-exchange with Na⁺ and acted as very effective antibacterial substances in the long term. Their bactericidal and bacteriostatic effects were determined. Generally, antibacterial compounds are effective when they are released from an inorganic carrier. Metallic silver was prepared by reduction of intercalated Ag⁺ with sodium borohydride. Antibacterial effects of metallic silver were not observed.     

Lysozyme-coated silver nanoparticles for differentiating bacterial strains on the basis of antibacterial activity

Lysozyme, an antibacterial enzyme, was used as a stabilizing ligand for the synthesis of fairly uniform silver nanoparticles adopting various strategies. The synthesized particles were characterized using UV-visible spectroscopy, FTIR, dynamic light scattering (DLS), and TEM to observe their morphology and surface chemistry. The silver nanoparticles were evaluated for their antimicrobial activity against several bacterial species and various bacterial strains within the same species. The cationic silver nanoparticles were found to be more effective against Pseudomonas aeruginosa 3 compared to other bacterial species/strains investigated. Some of the bacterial strains of the same species showed variable antibacterial activity. The difference in antimicrobial activity of these particles has led to the conclusion that antimicrobial products formed from silver nanoparticles may not be equally effective against all the bacteria. This difference in the antibacterial activity of silver nanoparticles for different bacterial strains from the same species may be due to the genome islands that are acquired through horizontal gene transfer (HGT). These genome islands are expected to possess some genes that may encode enzymes to resist the antimicrobial activity of silver nanoparticles. These silver nanoparticles may thus also be used to differentiate some bacterial strains within the same species due to variable silver resistance of these variants, which may not possible by simple biochemical tests.     

锌-铕抗菌材料的制备

通过溶胶-凝胶法制备出Zn-Eu抗菌白炭黑,该产品是一种含有稀土Eu3+的新型无机抗菌材料,与只单载Zn2+的抗菌白炭黑相比,该新型无机抗菌材料的抗菌性能更加显著.通过单因素实验探究Zn2+浓度、Eu3+浓度和反应时间对产品杀菌率的影响,得到最佳制备方案:Zn2+浓度为0.8 mol·L-1、Eu3+浓度0.005 mol·L-1、反应时间1 h.最佳条件下制备得到抗菌性能优良的Zn-Eu抗菌白炭黑,并对其进行FTIR、SEM和ICP-OES表征.FTIR结果显示,Zn2+和Eu3+加入后没有明显改变载体白炭黑的基本结构.SEM和ICP-OES分析表明,Zn-Eu抗菌白炭黑粒径较小,分散性较好并且Zn2+和Eu3+均担载在了载体白炭黑上.     

Na+浓度对化学增强钠铝硅酸盐玻璃性能的影响

熔盐中少量的Na⁺并不会对玻璃的离子交换效果产生明显影响,但当熔盐中Na⁺浓度不断增大时,化学增强钠铝硅酸盐玻璃的性能开始受到影响。本文采用一步法离子交换工艺研究了熔盐中Na⁺浓度对不同厚度化学增强钠铝硅酸盐玻璃表面压应力、应力层深度和弯曲强度等性能的影响。研究表明:熔盐中Na⁺浓度不断增大时,化学增强钠铝硅酸盐玻璃的表面压应力、弯曲强度下降;弯曲强度下降最多可达175 MPa,此时玻璃的表面压应力下降了57.4 MPa;熔盐中Na⁺浓度变化未对化学增强钠铝硅酸盐玻璃的应力层深度和可见光透过率产生明显影响。     

Nontoxic glasses: Preparation,structural, electrical and biological properties

Bacterial infections affect about 1 in 5 patients who receive a dental implant within 5 years of surgery. To avoid the implant rejection it is necessary for the development of innovative biomaterials, with addition or substitution of the ions, for implant coatings that promote a strong bond with the new host bone and antibacterial action. The objective of this work was to synthesize a bioactive glass with different silver concentrations to evaluate their antibacterial performance. The glasses were synthesized with up to 2% silver content by melt-quenching. Structural, morphological, biological, and electrical properties of all samples were studied. The biological behavior was evaluated through cytotoxicity tests and antibacterial activity. The structural analysis shows that the introduction of silver do not promote significant changes, not altering the advantageous properties of the bioglass of the bioglass. It was verified that the glasses with a silver content from 0.5% to 2%, completely prevented the growth of both Staphylococcus aureus and Escherichia coli while being nontoxic toward mammalian cells. Therefore, these bioglasses are promising materials to be used in the production of dental implants with antimicrobial activity.     

纳米ZnO-TiO2复合粉体的制备及抗菌性能的研究

目的:制备纳米级的ZnO-TiO2复合粉体,研究纳米ZnO-TiO2与单用纳米TiO2和纳米ZnO两种抗菌剂的抗菌能力。方法:本实验以ZnCl2和TiCl4为原料制备纳米级的ZnO-TiO2复合粉体,再选择了大肠杆菌和金黄色葡萄球菌为代表菌株,采用了纸片扩散法,对纳米ZnO-TiO2复合粉体抗菌剂进行了抗菌性研究,并与单用纳米TiO2和纳米ZnO两种抗菌剂抗菌性能进行比较。结果表明:纳米ZnO-TiO2复合粉体抗菌剂对代表菌株表现出比单用纳米ZnO或TiO2抗菌剂有更好的抗菌能力。在此基础上对相关抗菌剂的抗菌机理进行了分析讨论。     

Morphology,physical properties,silver release,and antimicrobial capacity of ionic silver‐loaded poly(l‐lactide) films of interest in food‐coating applications

In the present study, silver ions were incorporated into a poly‐(l ‐lactide) (PLA) matrix by a solvent casting technique using different solvents and glycerol as plasticizer. The effect of the different formulations on the morphology, thermal, mechanical and color properties were first evaluated. Additionally, a thorough study of the silver ions release to an aqueous environment was also monitored over time by anodic stripping voltammetry and correlated with the antimicrobial performance against S. enterica. The incorporation of silver contents of up to 1 wt % did not affect morphology, thermal or mechanical properties of the films. A sustainable, antibacterial effectiveness was found for the films in liquid medium and a breakpoint of 10–20 μg L^?1 silver was established under the stated conditions, evincing silver ion releasing technologies may be applied to liquid environments while complying with current legislation. This study provides insight into the structure properties relationship of these antibacterial polylactide materials of significant potential in coating applications. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41001.