负载纳米银的埃洛石纳米管/聚醚砜杂化超滤膜的制备

以聚醚砜(PES)为膜材料,N, N-二甲基乙酰胺(DMAc)为溶剂,聚乙烯吡咯烷酮(PVP)和负载纳米银的埃洛石纳米管(Ag- HNTs)为添加剂,采用相转化法制备聚醚砜超滤膜。系统地考察了添加剂(Ag- HNTs)含量对膜性能的影响,并用抑菌圈试验研究了所制膜的抗菌效果。结果表明：硅烷偶联剂KH-792中的甲氧基与HNTs上的羟基成功地发生反应,并且接枝量为0.105g (KH-792)?g -1 (HNTs);改性后的HNTs与Ag成功地发生络合反应,并且络合量近似为0.145g (Ag)?g -1 (HNTs);溶剂中负载纳米银的埃洛石纳米管(Ag- HNTs)所占比例的增加能提高膜的水通量,而截留率保持在95%左右。所制备的膜对大肠杆菌和金黄色葡萄球菌有较强的抑制作用。     

Novel antibacterial composite of coal/LLDPE loaded with silver ions

A novel antibacterial composite of coal/LLDPE (linear low density polyethylene) loaded with silver ions (ACCPE) was prepared by means of solid–liquid phase adsorption and extrusion. The composite was characterized by IR, XRD and SEM, and the mechanical, rheological, and Ag⁺‐releasing, and antibacterial properties of the composite were investigated. We discover that the ACCPE shows favorable mechanical properties, features a higher processability and antibacterial activity, and the coal and silver ion possess superimposed effect on antibacterial activity against Escherichia coli. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

An antibacterial submicron fiber mat with in situ synthesized silver nanoparticles

This work presents an alternative approach for fabricating electrospun submicron highly hydrophilic fiber mats loaded with silver nanoparticles. These fiber mats show a high efficient antibacterial behavior, very attractive for applications like wound healing and skin regeneration processes. The fabrication method is divided in two steps. First, poly(acrylic acid) (PAA) and β‐cyclodextrin (β‐CD) submicron fibers were electrospun and further stabilized using a thermal treatment, yielding stable hydrogel‐like fibers with diameters ranging from 100 nm up to several microns. In the second step, silver ions were loaded into the fibers and then reduced to silver nanoparticles in‐situ. The electrospinning parameters were adjusted to achieve the desired properties of the fiber mat (density, size) and afterwards, the characteristics of the silver nanoparticles (amount, size, aggregation) were tuned by controlling the silver ion loading mechanism. Highly biocide surfaces were achieved showing more than 99.99% of killing efficiency. The two‐step process improves the reproducibility and tunability of the fiber mats. To our knowledge, this is the first time that stable hydrogel fibers with a highly biocide behavior have been fabricated using electrospinning. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Ultrasound‐assisted coating of nylon 6,6 with silver nanoparticles and its antibacterial activity

A silver/nylon 6,6 nanocomposite containing 1 wt % metallic silver has been produced from an aqueous solution of silver nitrate in the presence of ammonia and ethylene glycol by an ultrasound‐assisted reduction method. The structure and properties of nylon 6,6 coated with silver have been characterized with X‐ray diffraction, transmission electron microscopy, scanning electron microscopy, energy‐dispersive X‐ray, X‐ray photoelectron spectroscopy, Raman spectroscopy, and diffused reflection spectroscopy measurements. The nanocrystals of pure silver, 50–100 nm in size, are finely dispersed on the polymer surface without damaging the nylon 6,6 structure. This silver–nylon nanocomposite is stable to many washing cycles and thus can be used as a master batch for the production of nylon yarn by melting and spinning processes. The fabric knitted from this yarn has shown excellent antimicrobial properties. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1423–1430, 2007     

A phenol-formaldehyde resin loaded with in situ synthesised silver nanoparticles

Attempts to obtain stable phenol-formaldehyde resins with silver nanoparticles embedded in their structure were performed in the study. Silver nanoparticles were formed in situ in the process of obtaining resole resins. The conditions of their formation allowed for effectively reducing silver ions and stabilising the creation of nanoparticles. Tannic acid was used as a reducing and stabilising substance and gelatin served as a supporting stabiliser. The possibility of using the obtained product as a wood binder was studied. It was confirmed that their adhesive properties are strong enough to bind blocks of pine wood. Thanks to the presence of silver nanoparticles, the product also exhibited antimicrobial activity which was confirmed against the Saccharomyces cerevisiae strain.     

Preparation and anticorrosion resistance of a self-curing epoxy nanocomposite coating based on mesoporous silica nanoparticles loaded with perfluorooctyl triethoxysilane

Organic coatings are prone to failure due to diffusion of the corrosion media toward the metal surface through the microcracks caused by internal and environmental stresses especially in immersion environment. In order to extend the service lifetime of organic coatings, we developed a self-curing epoxy resin/perfluorooctyl triethoxysilane (POTS)-loaded mesoporous silica nanoparticles (MSNs) nanocomposite (SEP/POTS-MSNs) coating, by embedding the POTS-loaded MSNs (POTS-MSNs) into an SEP resin. Fourier transform infrared, X-ray photoelectron spectroscopy, and Brunauer–Emmett–Teller analyses were conducted to confirm the successful loading of POTS in the MSNs. Thermogravimetric analysis was used to characterize the loading amount of POTS. The corrosion protection properties of the SEP, SEP/MSNs, and SEP/POTS-MSNs coatings were evaluated by electrochemical impedance spectroscopy and potentiodynamic polarization tests. The results indicate that the SEP/POTS-MSNs coating with only 30 μm thickness showed corrosion resistance with Z _{f = 0.01 Hz} of 4.7 × 10⁸ Ω/cm² and i_corr of 0.026 nA/cm² after 58 hr of immersion in boiling water, which were both two orders of magnitude higher than those of the SEP coating. The SEP/POTS-MSNs coating combines the advantages of the SEP coating and the POTS-MSNs. We anticipate that the SEP/POTS-MSNs coating has promising potential for use in immersion environments.     

Discoloration mechanism of UV-curable polymer/metal hybrid coating

The purpose of this study is to conduct an in-depth analysis of the discoloration mechanism of UV-curable polymer/metal hybrid coating. A variety of technical approaches, including microscopic, spectroscopic, and chromatographic analysis techniques, were used to investigate the nature of discoloration and the root cause. The hybrid coating has a typical multilayered structure consisting of a base coat, a vacuum deposited metal layer, and a top coat. The results obtained by microscopic and spectroscopic analyses demonstrated that the discoloration of the hybrid coating stemmed from yellowing of the top coat. Deterioration or degradation of the metal component in the vacuum deposited metal layer was not confirmed. The results of an analysis of additives in the discolored top coat showed that there is a small quantity of unreacted photoinitiators remaining in the top coat. From the results of solvent extraction and gel content measurement, it is believed that an excessive amount of photoinitiators was used in the resin of the top coat and one of the residual unreacted photoinitiators caused yellowing of the top coat.     

Facile fabrication of polyethylene/silver nanoparticle nanocomposites with silver nanoparticles traps and holds early antibacterial effect

Antibacterial polyethylene (PE)/silver nanoparticle (AgNP) nanocomposites containing AgNPs at concentrations of 5 × 10^?5, 5 × 10^?4, and 5 × 10^?3 wt % were fabricated and tested. Transmission electron microscopy revealed an even dispersion of surface AgNPs in the PE/AgNP nanocomposites. No AgNP agglomeration was observed. The tensile strength, elongation at break, and Young's modulus of these PE/AgNP nanocomposites were similar to those of neat PE. Differential scanning calorimetry demonstrated that the PE/AgNP nanocomposites and neat PE had similar melting and crystallization temperatures of 126 ± 0.5 and 109 ± 0.6°C, respectively. The heats of fusion of the PE/AgNP nanocomposites containing AgNPs at concentrations of 5 × 10^?5 and 5 × 10^?4 and of 5 × 10^?3 wt % were lower than those of neat PE by 5 and 7%, respectively. These PE/AgNP nanocomposites were immersed in shaking liquid cultures of the potential pathogenic bacteria Escherichia coli, Bacillus subtilis, and Salmonella typhimurium in the lag phase. The results show that the growth rates of all of the tested bacteria were restricted effectively after 1.5, 3, and 6 h of cultivation, respectively. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43331.     

A method for coating a polymer inclusion membrane with palladium nanoparticles

The preparation of palladium nanoparticles on the surface of a polymer inclusion membrane (PIM) consisting of 30 wt% di-(2-ethylhexyl)phosphoric acid and 70 wt% poly(vinyl chloride) is described. The Pd(II) ion was firstly extracted into the membrane via cation-exchange and then subsequently reduced to form clusters of palladium nanoparticles on the membrane surface. The reducing agents investigated were NaBH₄, trisodium citrate, sodium formate, and l-ascorbic acid. Best results were obtained with l-ascorbic acid which at pH 2.0 formed a uniform layer of palladium nanoparticle clusters on the surface of the PIM with an average nanoparticle size of 38 nm.Factors such as pH, temperature and intensity of mixing of the l-ascorbic acid solution, reduction time and Pd(II) loading of the PIM were found to have a significant influence on the surface coverage and size of the palladium nanoparticles.     

载银蛭石抗菌剂的制备及抗菌性能研究

以新疆伊犁蛭石为原料,首先对蛭石进行预处理,主要经过酸化、热处理及钠化处理,其次采用离子交换法制备了载银蛭石抗菌剂,最后通过对反应温度、反应时间、硝酸银浓度和pH对产品载银量影响的探讨,优化出制备载银蛭石的最佳工艺条件：反应温度为50 ℃;反应时间为5 h;硝酸银浓度为0.1 mol/L;pH为5。在最佳工艺条件下得到的产品载银量最大,最大载银量为5.23%（载银质量分数）。通过抑菌环法测试产品对大肠杆菌和金黄色葡萄球菌的抗菌活性,表明载银蛭石具有很强的抗菌性能。     

Highly transparent antibacterial hydrogel-polymeric contact lenses doped with silver nanoparticles

Biocompatible polymers such as poly(vinyl alcohol) (PVA) and poly(vinyl pyrrolidone) are used to prepare hydrogels for biomedical applications, including optical applications such as the manufacture of sensing devices, cosmetic and smart, and medical contact lenses, among others. In this study, three contact lenses were prepared by doping PVP-PVA supportive hydrogel with 0.1, 0.5, and 1 wt% of laboratory-manufactured Ag NPs. The work demonstrates the evaluation of vision correction through each lens and the effect of changing the concentration of silver on its refractive index. The simulation involved the design and simulation of an aberrated human eye based on the Liou and Brennan model (LBM), and the insertion of the contact lenses for vision correction using the ZEMAX optical design program. This work also included a study of the antimicrobial properties of the resulting hydrogel contact lenses doped with Ag NPs. The resulting refractive index of one PVP-PVA-Ag lens was relatively high at 532 nm = 1.604, which made the lens provide the highest image contrast (the lowest MTF curve degradation) of 0.883 ± 0.027 at 20 cycles/mm and an RMS nearly the Airy disc diameter of 3.983 μm. PVA was used in combination with PVP for stabilizing Ag NPs to give the contact lenses an antibacterial property. Finally, the optimum contact lens with a 1 wt% Ag NPs concentration showed the highest inhibition activity.     

Hydroxyapatite-based nanoparticles as a coating material for the dentine surface: An antibacterial and toxicological effect

In this study, nano sized hydroxyapatite (nHAp) and Ag(I) doped hydroxyapatite (Ag-nHAp) particles were synthesized by the precipitation method and used as a coating material for remineralization on caries-affected dentine samples. Characterization studies of both the synthesized hydroxyapatite-based particles and the coated dentine samples were performed using instrumental techniques such as SEM and FTIR, and then toxicity and antibacterial properties were also evaluated. It was observed that dentine samples were effectively coated by both nHAp and Ag-nHAp particles which have no toxic effects. Furthermore, the coating of nano-hydroxyapatite on dentine samples positively contributed to the viability of L929 fibroblast cells and also provided an antibacterial effect against to bacteria such as S. mutants, C. albicans and E. coli bacteria that are most frequently caused caries in the teeth. While all type of bacteria was eliminated by the nHAp coated dentine samples at 24th, Ag-nHAp coated dentine samples removed to all bacteria type at 1st.     

Effect of coordination number on the formation of silver nanoparticles in polymer/silver salt complex membranes

Polymer/silver salt complex membranes consisting of AgBF₄ dissolved in poly(2-ethyl-2-oxazoline) (POZ) exhibited higher separation performance for propylene/propane mixtures but gradual decrease of separation properties, primarily due to the reduction of silver ions to silver nanoparticles. In this study, the effect of salt concentration on the formation of silver nanoparticles in POZ/AgBF₄ complex membranes was investigated. Separation test showed that 1/0.5 POZ/AgBF₄ complex membrane exhibited improved long-term stability on the membrane separation performance for propylene/propane mixtures compared to 1/1 POZ/AgBF₄ complex membrane. The stability improvement would be attributed to the suppression of the reduction of silver ions to silver metal nanoparticles, resulting from the higher coordination number of silver ions to carbonyl oxygens of POZ in 1/0.5 POZ/AgBF₄ membrane than 1/1 membrane. Transmission electron microscopy (TEM) and UV–visible spectra results confirmed that the rate of silver metal nanoparticle formation in the 1/0.5 POZ/AgBF₄ complex membrane was significantly retarded compared to that of 1/1 POZ/AgBF₄ complex membrane. It is therefore concluded that the coordination number of silver ions for carbonyl oxygens is of pivotal importance in controlling the reduction reaction of silver ions to silver metals and consequently improving the membrane separation performance for propylene/propane mixtures.     

Preparation of polymer nanoparticles loaded with doxorubicin for controlled drug delivery

The preparation of polymer nanoparticles loaded with an active principle, commonly used in cancer treatment, is investigated here from the experimental point of view. The main novelty of this work stands in the use of continuous confined impinging jets mixers in combination with realistic materials, notably the biodegradable and biocompatible copolymer poly(methoxypolyethyleneglycolcyanoacrylate-co-hexadecylcyanoacrylate) together with two forms of the drug doxorubicin. To our knowledge this is the first attempt to use for such a system a device that can be operated continuously and can be easily scaled up. Nanoparticles are produced via solvent-displacement experimenting different solvents; the effect of the other operating parameters is also investigated. Nanoparticles are characterized in terms of their size distribution and surface properties; for a limited number of samples prepared with the optimized preparation protocol further characterization (in terms of drug loading, incorporation and release profiles) is also carried out. Collected results show that the overall approach is capable of producing nanoparticles with controlled particle size distribution, drug loading and good reproducibility and that on the contrary of what reported in the literature the presence of the active principle does play an important role.     

An antibacterial composite system based on multi-responsive microgels hosting monodisperse gold nanoparticles

A multi-responsive microgel having response to pH, temperature, and salt concentration was successfully prepared using a water-soluble monomer. Microgels were readily prepared from 2-(N-morpholino)ethyl methacrylate (MEMA) via emulsion polymerization using glycidyl methacrylate as a comonomer cross-linker. The morpholino groups of MEMA residues of microgels were able to give complexation with metal containing anions such as AuCl₄ ^? in acidic conditions. The reduction of aurate ions with sodium borohydride led to immobilized-gold nanoparticles (AuNP) in the microgel system. Average particle diameters of AuNPs were determined to be 10 ± 2 nm. The resulting AuNP-microgel system was examined as a nanoreactor for catalyst system and determined to be very effective in the reduction of 4-nitrophenol model reaction in aqueous media. AuNPs-microgel composite system had antibacterial properties against several Gram-positive and Gram-negative bacteria similar to amoxicillin. This P(MEMA-co-GMA) microgel is also very useful for different applications such as a host for metal nanoparticle production, a drug carrier or drug delivery system.     

一种防渗透硅烷纳米粒子/聚乳酸复合超疏水涂料

以十六烷基三甲氧基硅烷与原硅酸四乙酯为原料,经溶胶-凝胶反应得到疏水硅烷纳米粒子,再将其加入到聚乳酸的二氯甲烷溶液中与硅烷偶联剂正丙氨基三乙氧基硅烷反应,得到一种具有优异防渗透性能的超疏水涂料。采用FTIR和SEM对涂料结构和形貌进行了表征。红外分析表明,硅烷偶联剂不参与化学反应。SEM表明,涂料的超疏水性源自表面多级拓扑结构。接触角测试表明,硅烷纳米粒子极大地提高了涂料的防水性,当硅烷纳米粒子用量为4%(以聚乳酸/二氯甲烷溶液总质量计)时,超疏水涂料的水接触角达到150°以上;在10～20min测试时间内,相对于单一疏水硅烷纳米粒子〔接触角降速150(°)/min〕和单一聚乳酸溶液〔接触角降速9.5(°)/min〕涂覆,疏水硅烷纳米粒子/聚乳酸复合防水涂料的涂覆大幅度提高了样品的防渗透性,接触角降速仅为0.8(°)/min,这是疏水硅烷纳米粒子的多级结构与聚乳酸优异的成膜性相结合的结果。     

The role of silver nanoparticles on mixed matrix Ag/cellulose acetate asymmetric membranes

Mixed matrix asymmetric membranes were prepared by the addition of silver nanoparticles to cellulose acetate/acetone/formamide casting solutions with ratios acetone/formamide varying from 1.44 to 2.77 to prepare ultrafiltration/nanofiltration membranes covering a wide range of hydraulic permeabilities. Binding of the silver nanoparticles to the polymer matrix is revealed through comparison of the FTIR spectra of the cellulose acetate and the Ag/cellulose acetate membranes. In the later, there is a decrease of the ratio between the bands intensities at 2,000–2,500 cm⁻¹. Membrane surface charge of the mixed matrix membranes varies with the pore size and pH, and when compared with cellulose acetate membranes there is a decrease of the negative surface charge densities. The silver nanoparticles in all mixed matrix membranes results in an enhancement of the hydraulic permeabilities, ranging from 10.8 kg m⁻² h⁻¹ bar⁻¹ to 67.1 kg m⁻² h⁻¹ bar⁻¹. POLYM. COMPOS., 38:32–39, 2017. © 2015 Society of Plastics Engineers     

Development of a yellow ceramic pigment based on silver nanoparticles

In this study a yellow pigment was obtained for third-fire ceramic decorations, based on silver nanoparticles synthesised by the method of chemical reduction in aqueous phase, using silver nitrate and polyvinylpyrrolidone as raw materials. Monitoring of the nanoparticle synthesis reaction by UV–vis spectroscopy allowed optimum operating conditions to be defined in preparing these particles for use as chromophores. Under these conditions, a stable suspension of Ag nanoparticles, which were well dispersed and had an average diameter of 20–30 nm, was obtained. Polyvinyl alcohol and tetraethyl orthosilicate were then added to the nanoparticle suspension to obtain the pigment precursor. The pigment precursor was directly applied on to fired glazed ceramic tile. Subsequent thermal treatment at moderate temperature (700 °C) yielded a layer less than one micron thick, which generated an intense yellow colour.     

An ac impedance study of the fractal geometry of silver films electrodeposited within a polymer matrix

Silver films (10^–6m) have been electrodeposited within a polymer matrix (10^–5 m) of polyvinylidene fluoride trifluoroethylene copolymer 60-40 cast on the surface of a stainless steel electrode. It is shown that the fractal geometry of the polymer-metal interface, which is not open to direct observation, can be characterized by means of ac impedance measurements made on the electrode in acetonitrile solution.     

Influence of silver on the structure,dielectric and antibacterial effect of silver doped bioglass-ceramic nanoparticles

We present the structural, dielectric, biocompatibility and antibacterial properties of nano-sized calcium phosphosilicate bioglass ceramics doped with 0, 2, 4 and 6 mol% Ag₂O. Sol-gel processes were chosen to synthesize the silver embedded nanosized glass ceramic particles. All samples were characterized by powder X-ray diffraction (XRD), thermogravimetric analysis, Fourier transform infrared (FTIR) spectroscopy, UV–visible and high resolution transmission electron microscopy (HR-TEM). The glass-ceramic nature of the samples is confirmed by XRD analysis. The FTIR spectra reveal the probable stretching and bending vibration modes of silicate and phosphate groups. UV–visible absorption spectra reveal the silver embedment as Ag⁺/Ag° form in the glass matrix. Nano-size of the glass ceramics and silver nanoparticle embedment in glass matrix are confirmed by HR-TEM analysis. Dielectric spectra of samples reveal non-Debye relaxation processes. The dielectric constant of samples initially decreased and then increased with Ag₂O content. The antibacterial activities of these bioceramics were tested with different bacteria using an agar well diffusion method. Silver doped samples show good antibacterial effects without compromising the formation of hydroxyapatites. The dielectric constant of the bioglass ceramics is correlated to their antibacterial performance, with low dielectric constants giving higher antibacterial activity.