In situ formation of silver nanoparticles in PMMA via reduction of silver ions by butylated hydroxytoluene

Silver nanoparticles (Ag NPs) were efficiently generated by in situ reduction of silver ions via butylated hydroxytoluene (BHT), in poly(methyl methacrylate). The characterization of Ag/PMMA by TEM, SEM, XRD, and FTIR indicated that Ag NPs with a face center cubic (fcc) crystal structure and a mean diameter of about 30 nm were dispersed in PMMA matrix with a relatively uniform distribution. In addition, the results of UV–Vis spectroscopy indicated that optical properties of the nanocomposite appeared mainly dependent on the reaction time and temperature. Increasing the reaction time and temperature make higher yield of Ag NPs. A provisional reduction mechanism was also proposed for the formation of the Ag NPs.     

Synthesis of Ag/SiO2 nanocomposite material by adsorption phase nanoreactor technique

Ag/SiO₂ nanocomposite was synthesized in a nanoreactor formed by adsorption layer on silica surface. Ag nanoparticles were prepared by the reduction of Ag ion with ethanol at alkaline condition. By using TEM and XRD, the effects of NaOH concentration, water and temperature on the appearance and grain size of Ag particles were analyzed, respectively. The adsorption curve of NaOH was measured by electrical conductivity meter. The experiment result revealed that Ag grain size decreased while increasing NaOH concentration or while increasing water in our system. Ag grain size increased with the increase of temperature. And Ag aggregated seriously when temperature is up to 60 °C. Finally, after exploring the optimum conditions of reaction, we successfully obtained the well-distributed Ag nanoparticles on surface of silica, and average grain size of Ag nanoparticles reached 5 nm.     

Electrochemical deposition of silver nanoparticles in multiwalled carbon nanotube-alumina-coated silica for surface-enhanced Raman scattering-active substrates

The work presents a novel surface-enhanced Raman scattering (SERS)-active surface prepared by electrochemical deposition of silver nanoparticles in multiwalled carbon nanotube (MWCNT)–alumina-coated silica (ACS) nanocomposite. The formation of Ag nanoparticles in MWCNT–ACS nanocomposite was investigated by scanning electron microscopy. It shows that Ag nanoparticles with a diameter of about 100–200 nm in the MWCNT–ACS nanocomposite and some Ag nanoparticles aggregated to form interconnected aggregates. The Ag–MWCNT–ACS-coated indium tin oxide substrate has a considerable effect on the Raman spectra with improvements of more than four times of magnitude as compared with the Ag-coated indium tin oxide substrate. The present methodology demonstrates that the composite composed of Ag, MWCNT, and ACS is suitable for potential plasmonic devices.     

Reversible oxidation/reduction of silver supported on silica aerogel: Influence of the addition of phosphate

Ag/SiO₂ and Ag₃PO₄/SiO₂ systems supported on silica aerogel were investigated using temperature-programmed reduction (TPR), UV-visible diffuse reflectance spectroscopy (UV-vis DRS), and infrared spectroscopy. The formation of highly dispersed silver particles, uniformly distributed along the surface and stabilized with silanol groups, was observed for Ag/SiO₂ system. Phosphate and silanol groups produce two states of silver localization in phosphate-containing system. The addition of phosphate onto the silica surface leads to the reversible oxidation/reduction of silver in the temperature range of 100–300°C with transitions of silver (particles 10–30 nm in size) to charged states (ions, clusters stabilized by phosphate groups). This reversible behavior of silver is stable, and the amount of silver involved in these processes remained constant (∼50%) for the series of consistent cyclic oxidation/reduction treatments.     

Preparation and characterization of nanocomposite ZnO–Ag thin film containing nano-sized Ag particles: influence of preheating,annealing temperature and silver content on characteristics

Nanocomposite ZnO–Ag thin film containing nano-sized Ag particles have been grown on glass substrate by spin-coating technique using zinc acetate dihydrate as starting precursor in 2-propanol as solvent and monoethanolamine as stabilizer. Silver nanoparticles were added in the ZnO sol using silver nitrate dissolved in ethanol-acetonitrile. Their structural, electrical, crystalline size and optical properties were investigated as a function of preheating, annealing temperature and silver content. The results indicated that the crystalline phase was increased with increase of annealing temperature up to 550 °C at optimum preheating temperature of 275 °C. Thermal gravimetric differential thermal analysis results indicated that the decomposition of pure ZnO and nanocomposite ZnO–Ag precursors occurred at 225 and 234 °C, respectively with formation of ZnO wurtzite crystals. The scanning electron microscopy and atomic force microscopy revealed that the surface structure (the porosity and grain size) of the ZnO–Ag thin film (the film thickness is about 379 nm) was changed compared to pure ZnO thin film. The result of transmission electron microscopy showed that Ag particles were about 5 nm and ZnO particles 58 nm with uniform silver nanoclusters. Optical absorption results indicated that optical absorption of ZnO–Ag thin films decreased with increase of annealing temperature. Nanocomposite ZnO–Ag thin films with [Ag] = 0.068 M and [Ag] = 0.110 M showed an intense absorption band, whose maximum signals appear at 430 nm which is not present in pure ZnO thin films. The result of X-ray photoelectron spectroscopy revealed that the binding energy of Ag 3d_5/2 for ZnO–Ag shifts remarkably to the lower binding energy compared to the pure metallic Ag due to the interaction between Ag and ZnO.     

Sol–gel and impregnated prepared silver TiO<Subscript>2</Subscript> semiconductors as photocatalysts for the UV decomposition of 2,4-<Emphasis Type="SmallCaps">d</Emphasis>: a comparative study of the preparation method

UV-photocatalytic oxidation of 2,4-dichlorophenoxyacetic acid (2,4-d) was studied on Silver–TiO₂ semiconductors prepared by co-gelling silver acetylacetonate and titanium butoxide (TiO₂–Ag) or by incipient impregnation with silver acetylacetonate (0.5 wt% Ag) of bare TiO₂ sol–gel and TiO₂–P25 supports. The comparative study shows that only a slight modification on the specific surface area was obtained on the TiO₂–Ag sample (60 m²/g) as compared to the TiO₂ sol–gel bare support (65 m²/g). XRD patterns of the samples show anatase as the crystalline phase present in the sol–gel TiO₂ preparations. By means of HRTEM and HAADF-STEM electron microscopy techniques, silver nanoparticles (<12.0 nm) were identified which are very small to be detected by XRD. The photocatalytic oxidation of the herbicide 2,4-d used as a model of contaminant show for the kinetic parameter t_1/2 values of 45 min for the TiO₂–Ag sample, while for the impregnated Ag/TiO₂ and Ag/P25 nanomaterials t_1/2 was 124 and 66 min, respectively. The higher photoactivity of the TiO₂–Ag photocatalyst is attributed to a combined effect of the silver nanoparticles in interaction with the titania semiconductor.     

Ag nanoparticles deposited onto silica,titania, and zirconia mesoporous films synthesized by sol–gel template method

A variety of Ag nanoparticles/oxide mesoporous films with templated silica, titania, and zirconia was synthesized by sol–gel method at glass, aluminum, and silicon substrates using metal alkoxides (tetraethoxysilane, titanium tetraisopropoxide, and zirconium tetrapropoxide) and AgNO₃ as precursors of oxide films and Ag nanoparticles, respectively, and Pluronic P123 as a template agent. Oxide films alone and Ag/oxide composites were characterized using hexane adsorption, X-ray diffraction (XRD), Raman and ultraviolet (UV)/vis spectroscopies, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) methods. The distribution of Ag nanoparticles within the films, their sizes, intensity, and position of surface plasmon resonance (SPR) absorbance band at λ = 400 nm, as well as the textural and structural characteristics of whole films depend on treatment temperature, types of substrates and oxide matrices, oxide crystallization, and Ag content. Ag nanoparticles form preferably on the outer surface of the films under lower sintering temperatures if the amount of loaded silver is low. Oxide crystallization (e.g., TiO₂) promotes silver embedding into the outer film layer. At higher silver content (≥10 at.%) and higher calcination temperature (873 K), silver nanoparticles could be entrapped more uniformly along the film profile because of more intensive evaporation of silver droplets from the outer surface of the films on heating.     

Polymer-nanoparticle composites composed of PEDOT:PSS and nanoparticles of Ag synthesised by laser ablation

Laser ablation of a solid target material in a liquid environment provides with an easy, straightforward and environmentally friendly method for nanoparticles synthesis as well as with the unique possibility of directly controlling the type of the nanoparticles surface ligands through the liquid choice. In this paper, laser ablation (10.4 ps, 1064 nm and 50 kHz) of a bulk silver target in deionized water, was carried out for nanoparticles synthesis. The synthesised nanoparticles are either pure Ag or A₂O₃ or a mixture of the two materials. Their size distribution follows log-normal function with a statistical median diameter of ≈5 nm. The nanoparticles colloidal solutions were directly mixed after synthesis, with the polymer solution poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) for the formation of polymer-nanoparticles nanocomposite. The nanoparticles readily form bonds with the sulphur atom of PEDOT which results in their uniform distribution within the polymer matrix as well as in a replacement by the nanoparticles of the PSS⁻ as the counteranions to the PEDOT⁺. These effects result in the reduction of the effective insulation of the polymer blend particles by the insulating PSS and furthermore in the electrical conductivity of the nanocomposite becoming higher (by ∼1.5 times) as compared with that of the pure polymer.     

Preparation and characterization of multi‐walled carbon nanotubes decorated with silver nanoparticles through ultraviolet irradiation reduction

A facile, green and efficient approach was applied to synthesize multi‐walled carbon nanotubes (MWNTs) decorated with silver nanoparticles (MWNT‐Ag) for further potential application. Oxidized MWNTs were decorated with silver nanoparticles (Ag NPs) via a method combining ultraviolet irradiation‐induced reduction and conventional silver mirror reaction without any reducing agent. The obtained product was characterized using various methods. X‐ray diffraction proved that the Ag NPs were synthesized successfully. Moreover, Ag NPs with a diameter of 80 nm, attached onto MWNTs, could be clearly observed in field emission scanning electron microscopy images, which also confirmed Ag NPs. Energy‐dispersive spectroscopy and transmission electron microscopy also indicated the presence of Ag NPs. Furthermore, thermogravimetric analysis was used to measure the content of Ag NPs in MWNT‐Ag, the result indicating that the weight content of Ag NPs was up to 31.88%. UV–visible absorption spectroscopy was adopted to evaluate the dispersion property of MWNT‐Ag. The result illustrated that MWNT‐Ag had a good dispersibility and stability in water. Characterization was also carried out through Fourier transform infrared spectroscopy, Raman spectroscopy and dynamic light scattering analysis.     

Sol–gel coating of cellulose fibres with antimicrobial and repellent properties

Multifunctional, water and oil repellent and antimicrobial finishes for cotton fibres were prepared from a commercially available fluoroalkylfunctional water-born siloxane (FAS) (Degussa), nanosized silver (Ag) (CHT) and a reactive organic–inorganic binder (RB) (CHT). Two different application procedures were used: firstly, one stage treatment of cotton fabric samples by FAS sol (i), as well as by a sol mixture constituted from all three precursors (Ag–RB–FAS, procedure 1S) (ii), and secondly, two stage treatment of cotton by Ag–RB sol and than by FAS sol (Ag–RB + FAS, procedure 2S) (iii). The hydrophobic and oleophobic properties of cotton fabrics treated by procedures (i)–(iii) before and after consecutive (up to 10) washings were established from contact angle measurements (water, diiodomethane and n-hexadecane) and correlated with infrared and XPS spectroscopic measurements. The results revealed that even after 10 washing cycles cotton treated with Ag–RB + FAS (2S) retained an oleophobicity similar to that of the FAS treated cotton, while the Ag–RB–FAS (1S) cotton fibres exhibited a loss of oleophobicity already after the second washing, even though fluorine and C–F vibrational bands were detected in the corresponding XPS and IR spectra. The antibacterial activity of cotton treated by procedures (i)–(iii) was tested by its reduction of the bacteria Escherichia coli and Staphylococcus aureus following the AATCC 100-1999 standard method and EN ISO 20743:2007 transfer method. The reduction in growth of both bacteria was nearly complete for the unwashed Ag–RB and Ag–RB–FAS (S1), but for the unwashed Ag–RB + FAS (S2) treated cotton no reduction of S. aureus and 43.5 ± 6.9% reduction of E. coli was noted. After the first washing, the latter two finishes exhibited nearly a complete reduction of E. coli but for the Ag–RB treated cotton the reduction dropped to 88.9 ± 3.4. None of the finishes retained antibacterial properties after 10 repetitive washings. The beneficial and long-lasting low surface energy effect of FAS finishes in the absence of Ag nanoparticles, which led to the “passive” antibacterial properties of FAS treated cotton fabrics, was established by applying the EN ISO 20743:2007 transfer method. The results revealed a reduction in bacteria of about 21.9 ± 5.7% (FAS), 13.1 ± 4.8% (Ag–RB–FAS (S1)) and 41.5 ± 3.7% (Ag–Rb + FAS (S2)), while no reduction of the growth of bacteria was observed for cotton treated with Ag nanoparticles after 10 repetitive washings. The physical properties (bending rigidity, breaking strength, air permeability) of finished cotton samples were determined, and showed increased fabric softness and flexibility as compared to the Ag–RB treated cotton, but a slight decrease of breaking strength in the warp and weft directions, while air permeability decreased for all type of finishes.     

Tuning the properties of a black TiO2-Ag visible light photocatalyst produced by a rapid one-pot chemical reduction

A highly efficient black TiO₂-Ag photocatalytic nanocomposite, active under both UV and visible light illumination, was synthesized by decorating the surface of 25 nm TiO₂ particles with Ag nanoparticles. The material was obtained via a rapid, one-pot, simple (surfactant and complexing agent free) chemical reduction method using silver nitrate and formaldehyde as a metal salt and reducing agent, respectively. The nanocomposite shows an increase of over 800% in the rate of photocatalytic methylene blue dye degradation, compared to commercial unmodified TiO_2, under UV-VIS illumination. Unlike pure TiO₂, the nanocomposite exhibits visible light activation, with a corresponding drop in optical reflectance from 100% to less than 10%. The photocatalytic properties were shown to be strongly enhanced by post-reduction annealing heat treatments in air, which were observed to decrease, rather than coarsen, silver particle size, and increase particle distribution. This, accompanied by a variation in the silver surface oxidation states, appear to dramatically affect the photocatalytic efficiency under both UV and visible light. This highly active photocatalyst could have wide ranging applications in water and air pollution remediation and solar fuel production.     

Preparation of silver nanoparticles in liquid crystalline systems

Silver nanoparticles preparation and the aggregation stability of the particles was investigated in lamellar liquid crystalline systems. A liquid crystal of HDTABr/pentanol/water was first prepared. The water content was next increased while keeping the mass ratio of HDTABr and pentanol constant. Silver nanoparticles were produced by replacing the aqueous phase by Ag sols of various concentrations (0.5–5×10^–3 mol/l) or by an in situ preparation method, i.e., interlamellar reduction of Ag⁺ ions in the liquid crystalline phase. The stability of the silver nanoparticles was monitored by UV-VIS spectroscopy and TEM. The particle size ranged from 5 to 44 nm. The kinetic of silver nanoparticle aggregation was investigated. The effect of nanoparticles on structural ordering in liquid crystals was studied by XRD measurements and it was established that the lamellar distance (d_L) was only slightly altered. Electronic Publication     

A new,simple, green,and one-pot four-component synthesis of bare and poly(α,γ,<Emphasis Type="SmallCaps">l</Emphasis>-glutamic acid)-capped silver nanoparticles

A simple and green chemical method has been developed to synthesize stable bare and capped silver nanoparticles based on the reduction of silver ions by glucose and capping by poly(α,γ,l-glutamic acid) (PGA). The use of ammonia during synthesis was avoided. PGA has had a dual role in the synthesis and was used as a capping agent to make the silver nanoparticle more biocompatible and to protect the nanoparticles from agglomerating in the liquid medium. The synthesized PGA-capped silver nanoparticles in the size range 5–45 nm were stable over long periods of time, without signs of precipitation. Morphological examination has shown that the silver nanoparticles had a nearly spherical, multiply twinned structure. The effects of the reaction temperature and the reaction time during the synthesis were investigated too. The biocompatibility of the PGA-capped silver nanoparticles is discussed in terms of in vitro toxicity with human intestinal Caco-2 cells. The samples were characterized by UV–Visible spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, and zeta potential measurements.     

Polyacrylamide/reduced graphene oxide-Ag nanocomposite as highly efficient antibacterial transparent film

In this study, preparation and characterization of polyacrylamide/reduced graphene oxide-Ag (PAM/rGO-Ag) nanocomposites as a new nanocomposite film were investigated. First, PAM/GO nanocomposite was synthesized by in situ polymerization strategy. Afterward, highly stable and uniformly distributed silver nanoparticles (Ag NPs) have been obtained with PAM/GO nanocomposite as nanoreactors via in situ reduction of silver nitrate (AgNO₃) using sodium borohydride (NaBH₄) as reducing agent. In addition, the prepared PAM/rGO-Ag nanocomposite was thermally annealed in order to achieve high-performance nanocomposite film with antimicrobial activities. The prepared nanocomposite was characterized by XRD, FT-IR, SEM, TEM and TGA. The obtained results demonstrate that the silver nanoparticles were well decorated and dispersed on the graphene oxide nanosheets. In fact, the GO nanosheets and polyacrylamide chains act as a support and stabilize the Ag nanoparticles. Moreover, antimicrobial activities of the films were also examined, and the films containing well-dispersed and stabilized Ag nanoparticles showed outstanding antibacterial activity.     

Cinnamon zeylanicum bark extract and powder mediated green synthesis of nano-crystalline silver particles and its bactericidal activity

The exploitation of various plant materials for the biosynthesis of nanoparticles is considered a green technology as it does not involve any harmful chemicals. The present study reports the synthesis of silver (Ag) nanoparticles from silver precursor using the bark extract and powder of novel Cinnamon zeylanicum. Water-soluble organics present in the plant materials were mainly responsible for the reduction of silver ions to nano-sized Ag particles. TEM and XRD results confirmed the presence of nano-crystalline Ag particles. The pH played a major role in size control of the particles. Bark extract produced more Ag nanoparticles than the powder did, which was attributed to the large availability of the reducing agents in the extract. Zeta potential studies showed that the surface charge of the formed nanoparticles was highly negative. The EC₅₀ value of the synthesized nanoparticles against Escherichia coli BL-21 strain was 11 ± 1.72 mg/L. ThusC. zeylanicum bark extract and powder are a good bio-resource/biomaterial for the synthesis of Ag nanoparticles with antimicrobial activity.     

Preparation and characterization of carbopol‐silver nanocomposites for efficient antimicrobial applications

Carbopol‐silver nanocomposites, CP‐Ag‐NCs, were prepared by a chemical reducing method by using formaldehyde as a reducing agent (nanocomposite F), and formaldehyde in the presence of an alkaline medium resulting from the addition of Na₂CO₃ (nanocomposite FC), or NaOH (nanocomposite FO) to enhance the rate of reduction of the silver ions. The UV‐visible spectra showed the appearance of bands centered around 275, 286, and 274 nm for the nanocomposites F, FC, and FO, respectively, attributed to small silver nanoparticles (Ag‐NPs) with an average size less than 10 nm. Other bands centered around 405 and 470 nm for the nanocomposites F and FC, respectively, were attributed to large Ag‐NPs with an average size greater than 50 nm. The absence of large Ag‐NPs in the nanocomposites FO makes them as the materials of choice for the preparation of selective ultrasmall Ag‐NPs with an average size less than 3 nm. Furthermore, photoluminescence was observed upon blue excitation of the ultrasmall colloidal Ag‐NPs. Scanning electron microscopy images showed a good dispersion of the metallic Ag‐NPs in the polymer matrix. Moreover, X‐ray diffraction patterns showed peaks corresponding to the face‐centered‐cubic of the Ag‐NPs. The nature of the interaction between carbopol and Ag‐NPs was further studied by attenuated total reflectance‐Fourier transform infrared spectroscopy, and the mechanism of reduction of the silver ions was proposed. The antimicrobial activities of the CP‐Ag‐NCs were examined against Escherichia coli and Candida albicans microorganisms. The results demonstrate that the CP‐Ag‐NCs can provide new applications of these nanocomposites as efficient sensors and antimicrobial materials.     

Nano silver coated patterned silica thin film by sol–gel based soft lithography technique

We report the fabrication of nano silver coated patterned silica thin film by sol–gel based soft lithography technique. Initially, silica gel film on soda lime silica glass was prepared by dipping technique from a silica sol of moderate silica concentration. A PolydimethylSiloxane elastomeric stamp containing the negative replica of the patterns of commercially available compact disc was used for embossing the film and the embossed film was cured up to 450 °C in pure oxygen atmosphere for oxide film. Finally, a precursor solution of AgNO₃ in water containing polyvinyl alcohol as an organic binder was made and used for coating on the patterned silica film by dipping technique and cured the sample up to 450 °C in reducing gas atmosphere to obtain nano silver layer. The formation of only cubic silver (~4.0 nm) and both cubic silver (~5.2 nm) and silver oxide (~3.6 nm) crystallites at 350 and 450 °C film curing temperatures respectively were confirmed by XRD measurements. The % of nano silver metal and silver oxide were 75.4 and 24.6 respectively. The nano-structured surface feature was visualized by FESEM whereas AFM revealed the high fidelity grating structure of the films. Presence of both spherical and rectangular structure (aspect ratio, 2.37) of nano silver/silver oxide was confirmed by TEM. The films were also characterized by UV–Vis spectral study. The patterned film may find application in chemical sensor devices.     

Green synthesis of Ag/Fe3O4 nanoparticles using Mentha extract: Preparation,characterization and investigation of its anti-human lung cancer application

In this study, silver nanoparticles (Ag NPs) were decorated on the surface of magnetic nanoparticles in an eco-friendly pathway applying Mentha extract as reducing/stabilizing agent. The morphological and physicochemical features of the prepared Ag/Fe₃O₄nanocomposite were determined using several advanced techniques. Hence, our protocol is green and advantageous in terms of- i) biochemical modified biocompatible nanocomposite; ii) nanomaterial providing high surface area and larger number reactive sites; iii) very simplistic synthetic procedure; vi) very low load of metal in the composite and v) high yield in short time. In the medicinal part, the anticancer properties of Ag/Fe₃O₄ nanocomposite against lung cancer cell lines were determined. The free radical for the antioxidant effects was DPPH. The IC₅₀ of Ag/Fe₃O₄ nanocomposite was 200 µg/ml in the antioxidant test. The IC₅₀ of the Ag/Fe₃O₄ nanocomposite were 183, 176, 169, and 125 µg/mL against lung cancer (NCI-H661, NCI-H1975, NCI-H1573, and NCI-H1563) cell lines, respectively. In addition, the current study offer that Ag/Fe₃O₄ nanocomposite could be a new potential adjuvant chemopreventive and chemotherapeutic agent against cytotoxic cells.     

Characterization of gold nanoparticles electrochemically deposited on amine-functioned mesoporous silica films and electrocatalytic oxidation of glucose

This study reports the preparation and characterization of gold nanoparticles deposited on amine-functioned hexagonal mesoporous silica (NH₂–HSM) films and the electrocatalytic oxidation of glucose. Gold nanoparticles are fabricated by electrochemically reducing chloroauric acid on the surface of NH₂–HSM film, using potential step technology. The gold nanoparticles deposited have an average diameter of 80 nm and show high electroactivity. Prussian blue film can form easily on them while cycling the potential between −0.2 and 0.6 V (vs saturated calomel electrode) in single ferricyanide solution. The gold nanoparticles loading NH₂–HSM-film-coated glassy carbon electrode (Au–NH₂–HSM/GCE) shows strong catalysis to the oxidation of glucose, and according to the cathodic oxidation peak at about 0.16 V, the catalytic current is about 2.5 μA mM⁻¹. Under optimized conditions, the peak current of the cathodic oxidation peak is linear to the concentration of glucose in the range of 0.2 to 70 mM. The detection limit is estimated to be 0.1 mM. In addition, some electrochemical parameters about glucose oxidation are estimated.     

Textile with silver silica spheres: its antimicrobial activity against <Emphasis Type="Italic">Escherichia coli and Staphylococcus aureus</Emphasis>

The aim of this study was to investigate antimicrobial activity of textiles doped with silver in different forms. Three types of textiles were prepared and examined: textiles doped with commercially available Ag nanoparticles, textiles doped with commercial colloidal silver and textiles doped with silver silica SiO₂/Ag spheres. The specimens of silica submicron spheres were synthesized by the sol–gel method as a matrix for biological active silver. The results of microbiological tests revealed that among three kinds of Ag doped textiles only these doped with SiO₂/Ag spheres are bacteriostatically active. During the experiments minimal inhibiting bacteria growth concentration of active SiO₂/Ag spheres added to textiles was determined.