Multifunctional properties of textile materials modified with titanium dioxide nanoparticles

U teorijskom delu teze predstavljene su mogućnosti modifikovanja tekstilnih materijala različitim nanočesticama. Dat je pregled literature o primeni nanočestica TiO2 na tekstilne materijale, kao i o mogućnostima modifikovanja tekstilnih materijala u cilju boljeg vezivanja nanočestica TiO2. Objašnjeni su mehanizmi dejstva nanočestica TiO2 na mikroorganizme, obojene nečistoće i efekat UV zaštite. Takođe je objašnjeno dejstvo nanočestica srebra na fotokatalitičku aktivnost nanočestica TiO2. Opisani su do sada korišćeni postupci za sintezu koloidnih nanočestica TiO2 različitih oblika i kristaliničnosti. U eksperimentalnom delu teze, ispitana je mogućnost modifikovanja poliestrskih (PES) i pamučnih (Co) tkanina koloidnim nanočesticama TiO2 u cilju dobijanja nanokompozitnih tekstilnih materijala sa multifunkcionalnim svojstvima. Da bi se poboljšala efikasnost vezivanja hidrofilnih koloidnih nanočestica TiO2 za PES i Co vlakna, površine ovih tkanina su prethodno aktivirane korona pražnjenjem na atmosferskom pritisku i RF plazmom na niskom pritisku. Funkcionalizacija površine PES vlakna je vršena i biopolimerom alginatom i poliakrilnom kiselinom. Ispitani su i efekti koji se na PES i Co tkaninama postižu kombinovanom obradom koloidnim nanočesticama TiO2 i srebra. Antibakterijska aktivnost PES i Co tkanina modifikovanih koloidnim nanočesticama TiO2 je ispitana prema Gram-negativnoj bakteriji Escherichia coli. Antimikrobna efikasnost materijala modifikovanih koloidnim nanočesticama TiO2 i srebra je ispitana prema Gram-negativnoj bakteriji E. coli, Gram-pozitivnoj bakteriji Staphylococcus aureus i kvascu Candida albicans. Odlična i na pranje postojana baktericidna efikasnost je postignuta kod PES i Co tkanina koje su pre obrade nanočesticama TiO2 modifikovane koronom ili RF plazmom. Takođe je utvrđeno da prethodna aktivacija površine PES tkanina alginatom i poliakrilnom kiselinom utiče na poboljšanje antibakterijske aktivnosti tkanina modifikovanih nanočesticama TiO2. Ustanovljeno je da se obradom PES i Co tkanina koloidnim nanočesticama TiO2 i srebra obezbeđuju izuzetna antimikrobna svojstva. PES i Co tkanine modifikovane nanočesticama TiO2 postižu maksimalan nivo UV zaštite koji se zadržava i nakon pet ciklusa pranja. Odlična svojstva samočišćenja obojenog zaprljanja od soka od borovnice su uočena kod tkanina koje su pre obrade nanočesticama TiO2 modifikovane koronom ili plazmom. Ustanovljeno je da nanočestice TiO2 deponovane na PES i Co tkaninama pokazuju izuzetnu fotokatalitičku aktivnost i nakon tri ciklusa fotodegradacije vodenog rastvora boje metilensko plavo. Poboljšanje antimikrobnih efekata, UV zaštite i fotokatalitičke aktivnosti nakon prethodnog modifikovanja tkanina je direktna posledica povećane efikasnosti vezivanja nanočestica srebra na aktiviranoj površini PES i Co vlakana što je utvrđeno XPS i AAS analizom.In the theoretical part of this thesis, the potentials of different nanoparticles to modify the textile materials are discussed. A review of possible applications of TiO2 nanoparticles onto textile materials is given. Potential modifications of textile materials in order to enhance the binding efficiency of TiO2 nanoparticles are described in detail. The mechanisms of TiO2 action on microorganisms, coloured stains and UV protection effect are discussed. Additionally, the influence of silver nanoparticles on photocatalytic activity of TiO2 nanoparticles was considered. Special emphasis has been given to developed routes for the synthesis of colloidal TiO2 nanoparticles of different shapes and crystallinities. In the experimental part of this thesis, the possibility of modification of polyester (PES) and cotton (Co) fabrics with colloidal TiO2 nanoparticles in order to develop the nanocomposite textile materials with multifunctional properties was studied. In order to enhance the binding efficiency of hydrophilic colloidal TiO2 nanoparticles to PES and Co fibres, the surface of these fabrics was activated by corona at atmospheric pressure and RF plasma at low pressures. PES fibres were also functionalized with biopolymer alginate and polyacrylic acid. The effects of combined treatment of PES and Co fabrics with TiO2 and silver nanoparticles were examined. Antibacterial activity of PES and Co fabrics modified with colloidal TiO2 nanoparticles was tested against Gram-negative bacterium Escherichia Coli. Antimicrobial activity of PES and Co fabrics modified with colloidal TiO2 and silver nanoparticles was tested against Gram-negative bacterium Escherichia Coli, Gram-positive bacterium Staphylococus Aureus and fungus Candida Albicans. It was found that PES and Co fabrics modified by corona and RF plasma prior to loading of colloidal TiO2 nanoparticles exhibited excellent antimicrobial properties and adequate laundering durability. PES fabrics treated with alginate and polyacrylic acid and subsequently loaded with colloidal TiO2 nanoparticles also provided desirable level of antibacterial activity. PES and Co fabrics modified with TiO2 nanoparticles reached the maximum level of UV protection that was preserved after five washing cycles. The self-cleaning effects tested on blueberry juice stains and photodegradation of methylene blue in aqueous solution confirmed the excellent photocatalytic activity of TiO2 nanoparticles deposited onto fibre surface. The results indicated that corona and RF plasma treatment of PES and Co fabrics prior to loading of TiO2 nanoparticles provided enhanced antibacterial, UV protective, self-cleaning and photocatalytic properties. This was due to improved binding efficiency of TiO2 nanoparticles which was proved by XPS and AAS

Impregnation of cellulose acetate films with carvacrol using supercritical carbon ioxide

Cellulose acetate films were impregnated with carvacrol using supercritical carbon dioxide. The supercritical impregnation process, conducted in a static regime at pressure of 21 MPa and temperature of 50°C, was optimized by variation in the processing time (30 and 120 min) and decompression rate (from 0.3 MPa/min to 36 MPa/min). Characterization of the obtained cellulose acetate films was performed by Atomic Force Microscopy and Differential Scanning Calorimetry. Effects of glycerol and carvacrol on the properties of the films were discussed. Release kinetics from the cellulose acetate film with 31.4% of carvacrol was investigated in a physiological saline solution. In addition, the Higuchi and Korsmeyer-Peppas release models fitted the carvacrol release curve well. Obtained cellulose acetate films impregnated with carvacrol can be of interest for the application in medicine as wound dressings considering their biocompatibility and biodegradability as well as their potential antimicrobial activity or in the food industry as an active food packaging

Thermodynamcis of molybdenum adsorption onto porous copolymer

Macroporous glycidyl methacrylate and ethylene glycol dimethacrylate copolymer functionalized with diethylene triamine, PGME-deta, was tested as molybdate ion adsorbent from aqueous solutions. Kinetics of Mo(VI) sorption was investigated in batch static experiments, in the temperature range 298-343 K. The temperature rise promotes Mo(VI) removal, with the maximum experimental adsorption capacity of 585 mg g-1 at 343 K. Thermodynamic parameters revealed spontaneous and endothermic nature of Mo(VI) adsorption onto PGME-deta.Physical chemistry 2012 : 11th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 24-28 September 201

Antimicrobial activity and cytotoxicity of silver-based nanoparticles in situ synthesized on cotton fabric using walnut leaf

U ovom radu je ispitana mogućnost in situ sinteze nanočestica na bazi srebra primenom ekstrakta lista oraha, na pamučnoj tkanini prethodno modifikovanoj limunskom kiselinom. Tokom sinteze su formirane sferne nanočestice prečnika oko 60 nm, koje su ravnomerno raspoređene po površini pamučnih vlakana. Prisustvo nanočestica na bazi srebra je obezbedilo odličnu antimikrobnu aktivnost prema bakterijama Staphylococcus aureus i Escherichia coli, kao i kvascu Candida albicans. Tekstilni nanokompozitni materijal nije citotoksičan prema ćelijama zdravih keratinocita kože (HaCaT linija) i zdravih fibroblasta (MRC-5 linija), što omogućava njegovu bezbednu primenu za medicinske potrebe.This study discusses the possibility to utilize walnut leaf extract for in situ synthesis of silver-based nanoparticles on cotton fabric previously modified with citric acid. Synthetized spherical nanoparticles with an average diameter of 60 nm were evenly distributed over the surface of cotton fibers. The presence of silver-based nanoparticles provided excellent antimicrobial activity against bacteria Staphylococcus aureus and Escherichia coli, and yeast Candida albicans. The textile nanocomposite did not show any cytotoxicity towards healthy skin keratinocytes cells (HaCaT line) and healthy fibroblast cells (MRC-5 line). Thus, it could be considered as a safe for potential medical applications

Multifunctional properties of textile materials modified with titanium dioxide nanoparticles

U teorijskom delu teze predstavljene su mogućnosti modifikovanja tekstilnih materijala različitim nanočesticama. Dat je pregled literature o primeni nanočestica TiO2 na tekstilne materijale, kao i o mogućnostima modifikovanja tekstilnih materijala u cilju boljeg vezivanja nanočestica TiO2. Objašnjeni su mehanizmi dejstva nanočestica TiO2 na mikroorganizme, obojene nečistoće i efekat UV zaštite. Takođe je objašnjeno dejstvo nanočestica srebra na fotokatalitičku aktivnost nanočestica TiO2. Opisani su do sada korišćeni postupci za sintezu koloidnih nanočestica TiO2 različitih oblika i kristaliničnosti. U eksperimentalnom delu teze, ispitana je mogućnost modifikovanja poliestrskih (PES) i pamučnih (Co) tkanina koloidnim nanočesticama TiO2 u cilju dobijanja nanokompozitnih tekstilnih materijala sa multifunkcionalnim svojstvima. Da bi se poboljšala efikasnost vezivanja hidrofilnih koloidnih nanočestica TiO2 za PES i Co vlakna, površine ovih tkanina su prethodno aktivirane korona pražnjenjem na atmosferskom pritisku i RF plazmom na niskom pritisku. Funkcionalizacija površine PES vlakna je vršena i biopolimerom alginatom i poliakrilnom kiselinom. Ispitani su i efekti koji se na PES i Co tkaninama postižu kombinovanom obradom koloidnim nanočesticama TiO2 i srebra. Antibakterijska aktivnost PES i Co tkanina modifikovanih koloidnim nanočesticama TiO2 je ispitana prema Gram-negativnoj bakteriji Escherichia coli. Antimikrobna efikasnost materijala modifikovanih koloidnim nanočesticama TiO2 i srebra je ispitana prema Gram-negativnoj bakteriji E. coli, Gram-pozitivnoj bakteriji Staphylococcus aureus i kvascu Candida albicans. Odlična i na pranje postojana baktericidna efikasnost je postignuta kod PES i Co tkanina koje su pre obrade nanočesticama TiO2 modifikovane koronom ili RF plazmom. Takođe je utvrđeno da prethodna aktivacija površine PES tkanina alginatom i poliakrilnom kiselinom utiče na poboljšanje antibakterijske aktivnosti tkanina modifikovanih nanočesticama TiO2. Ustanovljeno je da se obradom PES i Co tkanina koloidnim nanočesticama TiO2 i srebra obezbeđuju izuzetna antimikrobna svojstva. PES i Co tkanine modifikovane nanočesticama TiO2 postižu maksimalan nivo UV zaštite koji se zadržava i nakon pet ciklusa pranja. Odlična svojstva samočišćenja obojenog zaprljanja od soka od borovnice su uočena kod tkanina koje su pre obrade nanočesticama TiO2 modifikovane koronom ili plazmom. Ustanovljeno je da nanočestice TiO2 deponovane na PES i Co tkaninama pokazuju izuzetnu fotokatalitičku aktivnost i nakon tri ciklusa fotodegradacije vodenog rastvora boje metilensko plavo. Poboljšanje antimikrobnih efekata, UV zaštite i fotokatalitičke aktivnosti nakon prethodnog modifikovanja tkanina je direktna posledica povećane efikasnosti vezivanja nanočestica srebra na aktiviranoj površini PES i Co vlakana što je utvrđeno XPS i AAS analizom.In the theoretical part of this thesis, the potentials of different nanoparticles to modify the textile materials are discussed. A review of possible applications of TiO2 nanoparticles onto textile materials is given. Potential modifications of textile materials in order to enhance the binding efficiency of TiO2 nanoparticles are described in detail. The mechanisms of TiO2 action on microorganisms, coloured stains and UV protection effect are discussed. Additionally, the influence of silver nanoparticles on photocatalytic activity of TiO2 nanoparticles was considered. Special emphasis has been given to developed routes for the synthesis of colloidal TiO2 nanoparticles of different shapes and crystallinities. In the experimental part of this thesis, the possibility of modification of polyester (PES) and cotton (Co) fabrics with colloidal TiO2 nanoparticles in order to develop the nanocomposite textile materials with multifunctional properties was studied. In order to enhance the binding efficiency of hydrophilic colloidal TiO2 nanoparticles to PES and Co fibres, the surface of these fabrics was activated by corona at atmospheric pressure and RF plasma at low pressures. PES fibres were also functionalized with biopolymer alginate and polyacrylic acid. The effects of combined treatment of PES and Co fabrics with TiO2 and silver nanoparticles were examined. Antibacterial activity of PES and Co fabrics modified with colloidal TiO2 nanoparticles was tested against Gram-negative bacterium Escherichia Coli. Antimicrobial activity of PES and Co fabrics modified with colloidal TiO2 and silver nanoparticles was tested against Gram-negative bacterium Escherichia Coli, Gram-positive bacterium Staphylococus Aureus and fungus Candida Albicans. It was found that PES and Co fabrics modified by corona and RF plasma prior to loading of colloidal TiO2 nanoparticles exhibited excellent antimicrobial properties and adequate laundering durability. PES fabrics treated with alginate and polyacrylic acid and subsequently loaded with colloidal TiO2 nanoparticles also provided desirable level of antibacterial activity. PES and Co fabrics modified with TiO2 nanoparticles reached the maximum level of UV protection that was preserved after five washing cycles. The self-cleaning effects tested on blueberry juice stains and photodegradation of methylene blue in aqueous solution confirmed the excellent photocatalytic activity of TiO2 nanoparticles deposited onto fibre surface. The results indicated that corona and RF plasma treatment of PES and Co fabrics prior to loading of TiO2 nanoparticles provided enhanced antibacterial, UV protective, self-cleaning and photocatalytic properties. This was due to improved binding efficiency of TiO2 nanoparticles which was proved by XPS and AAS

Funkcionalizacija PLA aerogelova pomoću TiO2 nanočestica

This study was aimed to prepare material with high porosity and photocatalytic activity by immobilization of TiO2 nanoparticles (NPs) onto poly(lactic acid) (PLA) aerogels. PLA aerogels were prepared in three steps: (1) dissolution of polymer in chloroform at 22 °C, (2) chloroform replacement with ethanol, and (3) supercritical CO2-drying at pressure 19 MPa and temperature 39 ºC. Immobilization of TiO2 NPs was performed by in situ and ex situ methods. Obtained samples were characterized using SEM, EDX, and FTIR analysis. Photocatalytic activity of developed material was tested by following decolorization of dye C.I. Acid Orange 7 in water solution. It was shown that the morphology of PLA aerogels was slightly affected by TiO2 NPs immobilization. PLA aerogels with TiO2 NPs immobilized by ex situ method sustained floatability during test period and provided a complete decolorization of dye solution after 330 minutes of illumination. High photocatalytic activity of the sample was preserved within three repeated cycles of dye decolorization.Cilj ovog istraživanja bio je priprema materijala velike poroznosti i fotokatalitičke aktivnosti imobilizacijom nanočestica TiO2 na aerogelove poli(mlečne kiseline) (PLA). PLA aerogelovi su pripremljeni u tri koraka: (1) rastvaranje polimera u hloroformu na 22 °C, (2) zamena hloroforma etanolom i (3) natkritično sušenje upotrebom CO2 na pritisku 19 MPa i temperaturi 39 ºC. Imobilizacija TiO2 nanočestica izvedena je in situ i ex situ metodama. Dobijeni uzorci su okarakterisani pomoću SEM, EDX i FTIR analize. Fotokatalitička aktivnost razvijenog materijala ispitana je prateći obezbojavanje vodenog rastvora boje C.I. Acid Orange 7. Pokazano je da imobilizacija TiO2 nanočestica ne utiče značajno na morfologiju PLA aerogelova. PLA aerogelovi sa TiO2 nanočesticama imobilisanim ex situ metodom održavali su plutabilnost tokom isitivanja i omogućili su potpuno obezbojenje rastvora boje nakon 330 minuta osvetljenja. Velika fotokatalitička aktivnost uzorka očuvana je tokom tri ponovljena ciklusa obezbojavanja rastvora boje

БИОСИНТЕЗА НАНОЧЕСТИЦА НА БАЗИ СРЕБРА НА НЕТКАНОМ ПОЛИПРОПИЛЕНСКОМ МАТЕРИЈАЛУ ЗА ЕФИКАСНУ АНТИМИКРОБНУ АКТИВНОСТ

The outbreak of the COVID 19 pandemic confirmed the importance of personal protective equipment including the respiratory face masks as barriers to pathogens. Taking into account that face masks are mainly composed of polypropylene (PP) non-woven materials this study explores the possibility of in situ biosynthesis of silver-based nanoparticles as an antimicrobial agent on PP material. A pomegranate peel extract was used as a “green” agent for synthesis and stabilization of nanoparticles. Hydrophobicity of PP fibers was overcome by modification with corona discharge at atmospheric pressure. In order to improve the binding of silver ions, corona modified PP material was impregnated with biopolymer chitosan in the presence of crosslinker 1,2,3,4-butane-tetracarboxylic acid. SEM analysis revealed the presence of spherical Ag-based nanoparticles on the fiber surface with an average size of approximately 69 nm. The higher the concentration of the precursor salt, the higher the silver content after the reduction. Larger amounts of Ag-based nanoparticles provided stronger antimicrobial activity against bacteria Escherichia coli and Staphylococcus aureus, and yeast Candida albicans.Појавом COVID 19 пандемије је потврђена важност употребе личне заштитне опреме као што су респираторне маске које пружају физичку заштиту од патогених сојева микроогранизама. Имајући у виду да се заштитне маске углавном производе од нетканог материјала од полипропиленских влакана, у овом раду је испитана могућност in situ биосинтезе наночестица на бази сребра као антимикробног средства на полипропиленском материјалу. Екстракт од коре нара је употребљен као „зелено“ средство за синтезу наночестица. Хидрофобност полипропиленских влакана је превазиђена њиховом модификацијом корона пражњењем на атмосферском притиску. У циљу побољшања везивања јона сребра, полипропиленски материјал модификован короном је импрегниран биополимером хитозаном у присуcтву умреживача 1,2,3,4-бутантетракарбоксилне киселине. ФЕСЕМ анализом је потврђено присуство сферних наночестица на површини влакана, просечних димензија око 69 nm. Већа концентрација раствора соли прекурсора доприноси већем садржају сребра након редукције. Веће количине честица на бази сребра обезбедиле су снажнију антимикробну активност према бактеријама Escherichia coli и Staphylococcus aureus и квасцу Candida albicans

Antimicrobial activity of viscose rayon fabric modified with chitosan and Ag nanoparticles

Potrebe za medicinskim tekstilom koji poseduje antimikrobna svojstva kontinualno rastu. U poslednje vreme se cine napori da se sinteza nanocestica Ag ostvari upotrebom zelenih redukcionih sredstava, a pre svega biljnih ekstrakta. U ovom radu su nanocestice Ag sintetisane na viskoznoj tkanini modifikovanoj biopolimerom hitozanom sa i bez prisustva umreživaca 1,2,3,4-butantetrakarboksilne kiseline primenom ekstrakta kore nara kao redukcionog sredstva. Uprkos razlici u sadržaju i velicini nanocestica Ag, oba uzorka pokazuju odlicnu antibakterijsku aktivnost prema bakterijamaS. aureusi E. coli, a još bolju antifungalnu aktivnost prema kvascu C. albicans. Pri tome je citotoksicnost ovih uzoraka prema celijama keratinocita ljudske kože niska.The needs for medical textiles with antimicrobial properties are continually growing. Recently many efforts have been made to synthesize Ag nanoparticles using green reducing agents, in particular plant extracts. In this study Ag nanoparticles were synthesized on viscose rayon fabric modified with biopolymer chitosan with or without crosslinker 1,2,3,4-tetrabutanecarboxylic acid by applying pomegranate peel extract as a reducing agent. Despite the difference in content andsize of Ag nanoparticles both samples showed excellent antibacterial activity against bacteria S. aureus and E. coli and even better against yeast C. albicans. The cytotoxicity of these samples onhuman keratinocyte cellswas low

In situ generation of Ag nanoparticles on polyester fabrics by photoreduction using TiO2 nanoparticles

This study discusses the possibility of in situ generation of Ag nanoparticles on polyester fabric by photoreduction of Ag+ ions with deposited TiO2 nanoparticles in the presence of amino acid alanine and methyl alcohol. The presence of TiO2/Ag nanoparticles on the polyester fiber surface was confirmed by XRD, XPS, and SEM analyses. Such nanocomposite textile material provides excellent antimicrobial activity against Gram-negative bacterium E. coli, Gram-positive bacterium S. aureus, and fungus C. albicans. Maximum microbial reduction was preserved even after ten washing cycles. In spite of satisfactory laundering durability, the release of silver occurred during washing. The leaching of silver was also present when the fabrics were exposed to artificial sweat at pH 5.5 and pH 8.0 for 24 h. In addition to excellent antimicrobial properties, TiO2/Ag nanoparticles imparted maximum UV protection to polyester fabrics