复合沸石抗菌材料及其抗菌性能的研究

本文利用离子交换法将沸石与具有抗菌性能的锌铜离子合成双组分抗菌沸石,研究了反应时间、温度、交换的金属溶液的浓度和沸石与金属离子溶液的固液比对抗菌剂载金属含量及抗菌性能的影响,同时也比较了单金属组分沸石与双金属沸石抗菌性能的差异。实验表明,制备锌铜双组分抗菌沸石的最佳工艺条件为：反应时间2h,温度90℃,沸石质量与金属离子溶液体积比1：10,锌铜含量相差最少则锌铜离子浓度比为1：1。     

载银4A沸石抗菌剂的制备及其抗菌性能的研究

以4A沸石为载体, AgNO3溶液为反应液,通过离子交换法,制备载银沸石抗菌剂.探讨了制备工艺对沸石交换性能的影响;通过X射线衍射分析表征了样品的结构,并对其抗菌性能进行了测定.结果表明:交换液的浓度、反应温度、反应时间、pH值等对沸石的交换性能有较大的影响;交换液浓度为0.1mol/L、pH值为6-8为宜,从能耗角度考虑,室温为宜,但从反应时间考虑,应该选用加热;样品对大肠杆菌、沙门氏菌具有良好的抗菌性能.     

载银沸石的制备及其在牛皮纸上的应用研究

采用离子交换法制备了载银沸石抗菌剂,并在质量分数为2%的PVA中添加不同浓度的载银沸石抗菌剂,制备了抗菌牛皮纸,研究了不同抗菌剂添加量下抗菌牛皮纸的厚度和定量的变化及抑菌与防霉效果。结果表明:制得的载银沸石中银离子含量较高,且沸石的基本结构未被破坏;添加载银沸石使纸张的厚度和定量略有增大,且当100mL质量分数为2%的表面施胶剂中载银沸石的添加量为0.5g时,抗菌牛皮纸对大肠杆菌的抗菌率达到99.94%,并能有效抑制黑曲霉菌的生长。     

海泡石载银锌双离子制备抗菌剂的工艺研究

针对含银离子无机抗菌剂的变色问题,研究了以海泡石为载体,银离子(Ag+)和锌离子(Zn2+)为抗菌成分,制备双离子型无机抗菌剂的工艺方法。通过原子吸收光谱检测海泡石所载抗菌离子的含量,对海泡石吸附Ag+及Zn2+的工艺条件进行了研究,并对所制银锌/海泡石进行了抗菌性和耐变色性测试和观察。结果表明,在本文实验条件下,当吸附溶液中的Zn2+与Ag+初始浓度摩尔比为10∶1时,海泡石所载的这两种抗菌离子的质量比也为10∶1以上,达到了增大海泡石载Zn2+量,减少其载Ag+量的目的。所制备的银锌/海泡石有良好的抗菌性和耐变色性。     

磁性Ag~+/有机5A沸石复合抗菌剂制备及其性能

分别采用回流法和水热合成法制备了铁酸钴(CoFe2O4)磁流体和5A沸石,再将二者复合制成CoFe2O4载量不同的磁性5A沸石,然后利用离子交换法制备Ag+载量不同的磁性银型5A沸石,接着与有机抗菌剂复合生成磁性Ag+/有机5A沸石复合抗菌剂,对其形貌、粒度、磁性能、抗菌性能及用于含菌废水处理后的磁分离回收性能进行了研究。结果表明,CoFe2O4的晶粒尺寸为12.7nm,性能稳定,具良好的超顺磁性;5A沸石多为完整的立方体晶形,纳米级CoFe2O4附着在5A沸石表面,磁性5A沸石具有超顺磁性,当铁酸钴的载量为25%时,磁性5A沸石的饱和磁化强度Ms为17.842A·m2/kg,剩余磁化强度Mr为4.8257A.m2/kg,矫顽力Hci为0.427T;当Ag+的吸附量达到271.71mg/g,有机抗菌剂添加量达到3.5%时,复合抗菌剂对金黄色葡萄球菌和大肠杆菌的抗菌率分别为99.02%和99.17%;磁性银型5A沸石用于含菌废水处理后,利用磁分离技术极易将悬浮液中的抗菌剂进行回收,当CoFe2O4载量为25%时,磁性5A沸石复合抗菌剂的磁分离回收率达到96.14%。     

载银沸石在抗菌牛皮纸中迁移实验研究

制备了载银沸石抗菌牛皮纸,运用原子吸收光谱研究了40℃下抗菌剂在蒸馏水、4%(体积分数)乙酸、65%乙醇、正己烷和橄榄油中的迁移情况。结果表明:抗菌剂添加量为0.5%的抗菌牛皮纸中含有载银沸石的初始质量浓度为2.85 mg/L。当不同食品模拟物在迁移时间分别为2,24,96,240,960 h时,没添加载银沸石的牛皮纸浸泡的食品模拟液中均未检测到载银沸石,而添加量为0.5%的抗菌牛皮纸在蒸馏水、4%乙酸和65%乙醇中均有迁移,且迁移量大小为:65%乙醇>4%乙酸>蒸馏水,但正己烷和橄榄油中未检测到抗菌剂。     

聚乙烯醇制备载银沸石抗菌包装纸及其机械性能研究

以沸石为载体,AgNO3 为反应溶液,通过离子交换方法,将具有抗菌性能的金属银离子固定在多孔性沸石表面,制成了载银沸石抗菌剂,检测了其对大肠杆菌的抑菌效果。实验结果表明,当AgNO3 溶液浓度为0. 1mol/ L,pH 值为6 ~8,反应温度为70 ℃,反应时间为3 h 时,制备的载银沸石抗菌效果最好。然后选择聚乙烯醇(PVA)作为施胶剂,将载银沸石溶于该施胶剂中,采用表面施胶法喷涂到纸张的表面,赋予纸张抗菌性能。经检测,使用聚乙烯醇(PVA)对纸和纸板进行表面施胶以后,纸张的耐破度、耐折度、环压强度、抗拉伸等强度较原纸都有所增强。     

固相离子交换法制备高效载银分子筛抗菌剂及其抗菌性能

以小粒径NaA分子筛为载体,硝酸铵和硝酸银为原料,采用固相离子交换法制备载银分子筛抗菌剂。研究AgNO_3的用量、反应温度和反应时间对载银分子筛载银量的影响。分析了载银分子筛的物相和形貌,考察了载银分子筛的抗菌性能、缓释性能及抗变色性能。结果表明,在反应体系n(NH_4A)∶n(AgNO_3)为1∶2,反应温度为400℃,反应时间为4h条件下制备的载银分子筛,其载银量达到(41.35±0.42)%(质量分数),对大肠杆菌(Escherichia coli)的最小抑菌浓度(Minimum inhibitory concentration,MIC)为10.42×10~(-6),杀菌率达到(98.36±0.28)%,抑菌圈直径为15.8 mm;对金黄色葡萄球菌(Staphylococcus aureus)的MIC值为12.50×10~(-6),杀菌率达到(97.43±0.19)%,抑菌圈直径为13.6mm。所制备的载银分子筛具有良好的缓释性能和抗变色性能。     

载锌辉沸石无机抗菌剂的制备与性能研究

以天然辉沸石为载体，通过载带Zn^2＋并对其稳定固化制备了载锌辉沸石无机抗菌剂，对抗菌剂粒度、白度等物理性能与抗菌性、抗菌耐久性和有害气体去除作用等功能性及微观结构特性进行了研究。载锌辉沸石无机抗菌剂平均粒径0．8gm，白度88，在涂料中应用对涂料白度基本无影响；载锌辉沸石无机抗菌剂具有优良的抗菌性和耐久性，浓度700gg／ml时对大肠杆菌和金黄色葡萄球菌的抑菌率为100％，经热水浸泡12h后抑菌率仍分别为99％和98．5％；抗菌剂中Zn^2＋均匀分布在辉沸石的部分孔道中；辉沸石内部存在较多的空余孔道，从而导致抗菌剂同时具有对有害气体的去除作用。     

等离子喷涂抗菌羟基磷灰石涂层研究

以磷酸锆载银抗菌剂作为添加剂, 制备真空等离子喷涂抗菌羟基磷灰石(HA)涂层, 并对涂层的形貌、组成、结合强度以及抗菌性能进行研究. 结果表明, 添加抗菌剂的HA涂层形貌没有发生明显改变. 当添加剂含量较大时(10wt%), 涂层中出现少量反应产物CaZr(PO₄)₂与Na₆CaP₂O₉. 掺入抗菌剂之后涂层的结合强度呈上升趋势, 而且随着抗菌剂百分比的增加, 涂层结合强度随之增大. 含抗菌剂5wt%以上的HA涂层对牙龈单胞卟啉菌(Pg)、具核梭杆菌(Fn)及伴放线杆菌(Aa)具有明显的抗菌作用, 抗菌力大小依次为Pg>Fn>Aa.     

Synthesis of Ag doped calcium phosphate particles and their antibacterial effect as additives in dental glass ionomer cements

Developing dental restorations with enhanced antibacterial properties has been a constant quest for materials scientists. The aim of this study was to synthesize silver doped calcium phosphate particles and use them to improve antibacterial properties of conventional glass ionomer cement. The Ag doped monetite (Ag-DCPA) and hydroxyapatite (Ag-HA) were synthesized by precipitation method and characterized using X-ray diffraction, scanning electron microscope and X-ray fluorescence spectroscopy. The antibacterial properties of the cements aged for 1 day and 7 days were evaluated by direct contact measurement using staphylococcus epidermis Xen 43. Ion concentrations (F^? and Ag⁺) and pH were measured to correlate to the results of the antibacterial study. The compressive strength of the cements was evaluated with a crosshead speed of 1?mm/min. The glass ionomer cements containing silver doped hydroxyapatite or monetite showed improved antibacterial properties. Addition of silver doped hydroxyapatite or monetite did not change the pH and ion release of F^?. Concentration of Ag⁺ was under the detection limit (0.001?mg/L) for all samples. Silver doped hydroxyapatite or monetite had no effect on the compressive strength of glass ionomer cement.     

银系抗菌剂对包装原纸性能的影响

目的 研究银系抗菌剂对包装原纸抗菌性能、白度和力学性能的影响。方法 选用乙酸银、纳米银、磺胺嘧啶银等3种不同的银系抗菌剂,采用表面涂布的方法制备出抗菌纸;选用大肠杆菌和金黄色葡萄球菌检测其抗菌性能;比较抗菌纸和空白试样的力学性能。结果 3种抗菌纸对大肠杆菌和金黄色葡萄球菌均有一定的抗菌效果,抑菌圈直径为0.35~5.46 mm,其中对金黄色葡萄球菌的抗菌效果最为明显;当抗菌液的质量分数为0~0.5%时,随着浓度的增加,乙酸银抗菌纸的抗菌性能随之增加;当抗菌液的质量分数为0~10%时,随着浓度的增加,纳米银抗菌纸的抗菌性能也逐渐增加;当抗菌液的质量分数为0.6%时,磺胺嘧啶银抗菌纸抗菌性能达到最佳;抗菌剂对包装原纸白度有一定影响,但对力学性能的影响不明显。结论 3种抗菌纸对金黄色葡萄球菌的抗菌效果比对大肠杆菌的优良,抗菌纸的抗菌性能与抗菌剂种类和浓度有关;抗菌处理对包装原纸的力学性能和表面结构影响不大,但乙酸银和纳米银抗菌剂会导致纸张白度的下降。     

Metal clusters and nanoparticles assembled in zeolites: an example of stable materials with controllable particle size

An ion-exchangeable zeolite (mordenite) is used to control the formation of nanoparticles and clusters within the solid matrix by the hydrogen reduction of metal ions (Ag⁺, Cu²⁺, and Ni²⁺). SiO₂/Al₂O₃ molar ratio in mordenite appears to be an efficient tool to manage the reducibility of the metal ions. Few-atomic silver clusters in line with the larger silver nanoparticles were observed with DRS for the reduced Ag⁺-exchanged mordenites. Cu²⁺-exchanged ones produce the copper nanoparticles with different optical appearance, and Ni²⁺-exchanged mordenites are reduced up to complicated species with no explicit assignment of metal particles under the conditions studied.     

Tuning photoluminescence of ZnS nanoparticles by silver

We report the results of investigation of the interaction of silver with presynthesized ZnS nanoparticles (NPs) that was stabilized by cetyl trimethyl ammonium bromide (CTAB). The photoluminescence properties of ZnS NPs were followed in the presence of Ag⁺ ions, Ag NPs and by the synthesis of Ag@ZnS core-shell nanoparticles. We observed that CTAB stabilized ZnS NPs emitted broadly in the region from 350–450 nm, when excited by 309 nm light. In the presence of Ag⁺ ions the emission peak intensity up to 400 nm was reduced, while two new and stronger peaks at 430 nm and 550 nm appeared. Similar results were obtained when Ag NPs solution was added to ZnS solution. However, when Ag@ZnS NPs were synthesized, the emission in the 350–450 nm region was much weaker in comparison to that at 540 nm, which itself appeared at a wavelength shorter than that of Ag⁺ ion added ZnS NPs. The observations have been explained by the presence of interstitial sulfur and Zn²⁺, especially near the surface of the nanocrystals and their interaction with various forms of silver. In addition, our observations suggest that Ag⁺ ions diffuse into the lattice of the preformed ZnS NPs just like the formation of Ag⁺ doped ZnS NPs and thus changes the emission characteristics. We also have pursued similar experiments with addition of Mn²⁺ ions to ZnS and observed similar results of emission characteristics of Mn²⁺ doped ZnS NPs. We expect that results would stimulate further research interests in the development of fluoremetric metal ion sensors based on interaction with quantum dots.     

Optimization of annealing treatment and comprehensive properties of Cu-containing Ti6Al4V-xCu alloys

The Ti6Al4V-Cu alloy was reported to show good antibacterial properties, which was promising to reduce the hazard of the bacterial infection problem. For the purpose of preparing Ti6Al4V-Cu alloy with satisfied comprehensive properties, it’s important to study the heat treatment and the appropriate Cu content of the alloy. In this study, high Cu content Ti6Al4V-xCu (x = 4.5, 6, 7.5 wt%) alloys were prepared, and firstly the annealing heat treatments were optimized in the α+β+Ti₂Cu triple phase region to obtain satisfied tensile mechanical properties. Then the effect of Cu content on the tribological property, corrosion resistance, antibacterial activity and cytotoxicity of the Ti6Al4V-xCu alloys were systematically studied to obtain the appropriate Cu content. The results showed that the optimal annealing temperatures for Ti6Al4V-xCu (x = 4.5, 6, 7.5 wt%) alloys were 720, 740 and 760 °C, respectively, which was resulted from the proper volume fractions of α, β and Ti₂Cu phases in the microstructure. The additions of 4.5 wt% and 6 wt% Cu into the medical Ti6Al4V alloy could enhance the wear resistance and corrosion resistance of the alloy, but the addition of 7.5 wt% Cu showed an opposite effect. With the increase of the Cu content, the antibacterial property was enhanced due to the increased volume fraction of Ti₂Cu phase in the microstructure, but when the Cu content was increased to 7.5 wt%, cytotoxicity was presented. A medium Cu content of 6 wt%, with annealing temperature of 740 °C make the alloy possesses the best comprehensive properties of tensile properties, wear resistance, corrosion resistance, antibacterial property and biocompatibility, which is promising for future medical applications.     

Modification of algae with zinc,copper and silver ions for usage as natural composite for antibacterial applications

Nanometer sized metal particles are used in many applications as antimicrobial materials. However in public discussion nanoparticular materials are a matter of concern due to potential health risks. Hence there is a certain demand for alternative antimicrobial acting materials. For this, the aim of this work is to realize an antimicrobial active material based on the release of metal ions from a natural depot. By this, the use of elemental metal particles or metal oxide particles in nanometer or micrometer scale is avoided. As natural depot four different algae materials (gained from Ascophyllum nodosum, Fucus vesicolosus, Spirulina platensis and Nannochloropsis) are used and loaded by bioabsorption with metal ions Ag⁺, Cu^2 + and Zn^2 +. The amount of metal bound by biosorption differs strongly in the range of 0.8 to 5.4 mg/g and depends on type of investigated algae material and type of metal ion. For most samples a smaller release of biosorbed Ag⁺ and Cu^2 + is observed compared to a strong release of Zn^2 +. The antibacterial activity of the prepared composites is investigated with Escherichia coli. Algae material without biosorbed metal has only a small effect on E. coli. Also by modification of algae with Zn^2 + only a small antibacterial property can be observed. Only with biosorption of Ag⁺, the algae materials gain a strong bactericidal effect, even in case of a small amount of released silver ions. These silver modified algae materials can be used as highly effective bactericidal composites which may be used in future applications for the production of antimicrobial textiles, papers or polymer materials.     

载银沸石抗菌剂的研究进展

介绍了银系抗菌剂的特点,综述了载银沸石抗菌剂的发展动态,并深入总结了其抗菌机理、制备影响因素及研究中存在的问题,为载银沸石进一步应用到纸包装材料上提供参考。     

Enhancement of photocatalytic activity and stability of Ag2CO3 by formation of AgBr/Ag2CO3 heterojunction in mordenite zeolite

Two serious problems for semiconductor photocatalysts are their poor photocatalytic activity and low stability. In this work, Ag₂CO₃ nanoparticles incorporated in mordenite zeolite (MOR) by a facile precipitation method. Silver bromide (AgBr) with different weight percentage (20%, 40% and 50%) was coupled into Ag₂CO₃-MOR composite and producing a series of novel AgBr/Ag₂CO₃-MOR nanocomposites. The effects of AgBr on the Ag₂CO₃–MOR catalyst for the photocatalytic degradation of methyl blue (MB) under visible light irradiation have been investigated. The structure, composition and optical properties of nanocomposites were investigated by UV–Visible diffuse reflectance spectroscopy (UV–Vis DRS), X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM). The prepared AgBr/Ag₂CO₃-MOR photocatalyst with the optimal content of AgBr (50 wt%) indicated higher photocatalytic activity than that of the Ag₂CO₃-MOR and Ag₂CO₃ for degradation of methylene blue (MB) under visible light irradiation. For studying of stability of nanocomposites, Fe⁺³ ions, as a cheap and available cocatalyst, was inserted into mordenite matrix (Fe³⁺/MOR) by impregnation method. The hybrid material (AgBr/Ag₂CO₃) was synthesized in the Fe³⁺/MOR matrix by precipitation method. The cycle experiments on the AgBr/Ag₂CO₃-Fe/MOR nanocomposite indicated that cocatalyst, not only to improve photocatalytic activity, but also enhance photoinduced stability of photosensitive silver compounds in all cycles with respect to MOR. On the basis of the experimental results, a possible mechanism for the enhanced photocatalytic activity and photoinduced stability of silver compounds by Fe³⁺ cocatalyst was proposed. The mordenite support played an important role in decreases of recombination of photogenerated electrons-holes and increases of MB absorption. The Fe cocatalyst reduced photocorrosion of silver compounds.     

Reduction behaviour of (AgNa)A and (AgM2+Na)A zeolites

The reduction of silver-exchanged A zeolites proceeds in at least two distinct steps. At lower reduction temperatures up to 500 K about 67% of the silver ions present in the lattice of the unreduced zeolites are reduced and charged silver clusters (Ag₃⁺) are formed. This process is accompanied by a redistribution of the remaining cations resulting in characteristic changes of the adsorption properties. The position of silver ions in (AgNa)A and (AgM²⁺Na)A zeolites does not influence their reduction behaviour in the first reaction step, The further reduction of the Ag₃⁺ clusters at higher temperatures depends on the Ag-exchange and on the kind of M²⁺ ion, It seems that the low temperature reduction proceeds over either Ag₉⁺ or Ag₉²⁺ species depending on the silver content.