Ana Marija Grancarić

Nanoparticles of activated natural zeolite on textiles for protection and therapy

Activated natural zeolite clinoptilolite is microporous hydrated aluminosilicates crystals with well-defined structures containing AlO4 and SiO4 tetrahedral linked through the common oxygen atoms. It is to point out that zeolites act as strong adsorbents and ion-exchangers but having many other useful properties. Zeolites are nontoxic substance, excellent for UVR and microbes protection, for proteins and small molecules such as glucose adsorption. Due to its cationexchange ability, zeolites have catalytic properties and for that multiple uses in medicine and industry, agriculture, water purification and detergents. The present paper is an attempt to modify cotton and polyester fabrics for summer clothing with addition of natural zeolite nanoparticles for achieving UV and antibacterial protective textiles. For this purpose cotton fabrics were mercerized and polyester fabrics modified by alkaline hydrolysis and by EDA (ethylenediamine) aminolysis. Zeolite in this paper refers to activated particles of clinoptilolite, with some fraction of nanoparticles produced by tribomechanical processing in the patented machine.

Novel cotton cellulose by cationisation during the mercerisation process—part 1: chemical and morphological changes

Cationisation is the modification of cotton cellulose by using quaternary ammonium compounds that block negative OH groups, thus resulting in electropositive cotton cellulose. It is an alternative method for achieving better adsorption of chemical compounds and substances, such as dyestuffs, fluorescent whitening agents, and other textile auxiliaries. The cationisation of cotton cellulose changes the surface electrical charge (electrokinetic potential) by significantly increasing its adsorption properties. The presented article investigated the chemical and morphological changes in cotton cellulose when cationised with an epihalohydrin, 2,3-epoxypropyl trimethyl ammonium chloride, after and during the mercerisation process. When comparing mercerised cotton with cationised cotton, it was concluded that cationisation during the mercerisation process using short-chain cationic compounds would result in a novel cotton cellulose that would bring a new dimension to cotton pre-treatment and finishing. The modified cotton would retain all the beneficial properties of mercerised cotton with a change of surface charge that would ensure further improvement in quality.

Novel cotton cellulose by cationization during mercerization—part 2: the interface phenomena

Cationisation during the mercerisation process with an epihalohydrin results in novel cotton cellulose that gives a new dimension to cotton pre-treatment and finishing. The modified cotton retains all the beneficial properties of mercerised cotton with a change of the surface charge that ensures further quality improvement. The present paper deals with systematic investigations of the interface phenomena of cationised cotton fabric with an epihalohydrin; 2,3-epoxypropyl trimethyl ammonium chloride during and after mercerisation process. The water, ionic surfactant and dyestuff adsorption, as well as surface free energy, electrokinetic potential, isoelectric point and point of zero charge determined according to the streaming current/streaming potential method; and specific amount of surface charge of modified cotton fabrics are researched.

Light Conversion and Scattering in UV Protective Textiles

Abstract The primary cause of skin cancer is believed to be a long exposure to solar ultraviolet radiation (UV-R) crossed with the amount of skin pigmentation in the population. It is believed that in childhood and adolescence 80% of UV-R gets absorbed, whilst in the remaining 20% gets absorbed later in the lifetime. This suggests that proper and early photoprotection may reduce the risk of subsequent occurrence of skin cancer. Textile and clothing are the most suitable interface between environment and human body. It can show UV protection, but in most cases it does not provide full sun screening properties. UV protection ability highly depends on large number of factors such as type of fibre, fabric surface and construction, type and concentration of dyestuff, fluorescent whitening agent (FWA), UV-B protective agents, as well as nanoparticles, if applied. Based on electronically excited state by energy of UV-R (usually 340-370 nm), the molecules of FWAs show the phenomenon of fluorescence giving to white textiles high whiteness of outstanding brightness by reemitting the energy at the blue region (typically 420-470 nm) of the spectrum. By absorbing UV-A radiation, optical brightened fabrics transform this radiation into blue fluorescence, which leads to better UV protection. Natural zeolites are rock-forming, microporous silicate minerals. Applied as nanoparticles to textile surface, it scatters the UV-R resulting in lower UV-A and UV-B transmission. If applied with other UV absorbing agents, e.g. FWAs, synergistic effect occurs. Silicones are inert, synthetic compounds with a variety of forms and uses. It provides a unique soft touch, is very resistant to washing and improves the property of fabric to protect against UV radiation. Therefore, the UV protective properties of cotton fabric achieved by light conversion and scattering was researched in this paper. For that purpose, the stilbene-derived FWAs were applied on cotton fabric in wide concentration range without/with the addition of natural zeolite or silicone- polydimethylsiloxane. UV protection was determined in vitro through ultraviolet protection factor. Additionally, the influence to fabric whiteness and hand was researched

Enzymatic Scouring for Better Textile Properties of Knitted Cotton Fabrics

SUMMARY Standard procedures of cotton scouring involve alkali treatment, usually with NaOH. Waxes, protein substances, pectin and other impurities are removed from fiber during alkali conditions and some damages occurred. Enzymatic cotton scouring with pectinases is ecologically and economically favorable, compared with traditional NaOH scouring, and has been used since 1999. In this work, alkali and enzymatic scouring were investigated under industrial conditions. After scouring, knitted fabrics were prebleached, bleached, reactive dyed in dark shade and softened. Textile properties of knitted fabrics were analyzed by degree of polymerization (DP), sewability and wicking length.

Silica Precursor as Synergist for Cotton Flame Retardancy

Purpose – The cotton and its blends is the most commonly used textile material in the design and production of protective clothing. However, as the cellulose textiles are the most flammable materials it is necessary to improve its flame retardancy. The government regulations have been the driving force for developing durable flame retardants finishes for textile, to improve its performance and to reduce the negative impact on the environment. The paper aims to discuss these issues. Design/methodology/approach – This paper investigates the effect of silica precursor (tetraethoxysilane – TEOS) added in bath with conventional flame retardant urea/ammonium polyphosphate in full and half concentration for achieving environmental-friendly cotton flame retardancy. Silica precursors have excellent thermal stability and high heat resistance with very limited release of toxic gases during the thermal decomposition. Synergistic effect between urea/ammonium polyphosphate and TEOS has been calculated. Thermal properties of treated cotton fabrics were determined by limiting oxygen index (LOI), thermogravimetric analysis (TGA) and microscale combustion calorimeter (MCC). Findings – TEOS, significantly improves the flame retardancy of cotton when added in the bath with conventional flame retardants urea/ammonium polyphosphate by increasing the LOI values and other thermal properties as increasing char residue measured by TGA and higher heat release rate measured by MCC. Originality/value – This paper represent a good synergistic effect between urea/ammonium polyphosphate and TEOS. This phenomena is evident in better thermal properties when TEOS was added in the bath with conventional flame retardant especially for half concentration of urea/ammonium polyphosphate.

Skin Cancer and UV Protection

Abstract The incidence of skin cancer is increasing by epidemic proportions. Basal cell cancer remains the most common skin neoplasm, and simple excision is generally curative. On the other hand, aggressive local growth and metastasis are common features of malignant melanoma, which accounts for 75% of all deaths associated with skin cancer. The primary cause of skin cancer is long exposure to solar ultraviolet radiation (UV-R) crossed with the amount of skin pigmentation and family genetics. It is believed that in childhood and adolescence, 80% of UV-R gets absorbed while in the remaining, 20 % gets absorbed later in the lifetime. This suggests that proper and early photoprotection may reduce the risk of subsequent occurrence of skin cancer. Reducing the exposure time to sunlight, using sunscreens and protective textiles are the three ways of UV protection. Most people think that all the clothing will protect them, but it does not provide full sun screening properties. Literature sources claim that only 1/3 of the spring and summer collections tested give off proper UV protection. This is very important during the summer months, when UV index is the highest. Fabric UV protection ability highly depends on large number of factors such as type of fiber, fabric surface, construction, porosity, density, moisture content, type and concentration of dyestuff, fluorescent whitening agents, UV-B protective agents (UV absorbers), as well as nanoparticles, if applied. For all of these reasons, in the present paper, the results of UV protecting ability according to AS/NZS 4399:1996 will be discussed to show that standard clothing materials are not always adequate to prevent effect of UV-R to the human skin; and to suggest the possibilities for its improvement for this purpose enhancing light conversion and scattering. Additionally, the discrepancy in UV protection was investigated in distilled water as well as Adriatic Sea water.

Textile Sensors Validatıon to Perform In Situ Structural Health Monitorıng of Textile Reinforced Thermoplastic Composites

Smart textile approach to realize textile sensors compatibility with composite technology is a very promising solution today. Optimisation of sensors need to carry out in order to prepare sensors having negligible affect on reinforcement geometrical and mechanical properties. Weaving of 2D fabrics due to checking the thermo-forming consolidation of textile sensors inserted is an important step to perform in situ structural health monitoring of composites. In this work, E-glass/polypropylene sensors based on poly (3,4-ethylenedioxythiophene)poly (styrenesulfonate) polymer complex were studied. Textile sensors showed resistance to high temperature and pressure by giving electrical resistance responses after 2D textile preforms consolidation and possibility to validate composites developed during tensile loading in situ.

New Textile Sensors for In Situ Structural Health Monitoring of Textile Reinforced Thermoplastic Composites Based on the Conductive Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) Polymer Complex

Many metallic structural and non-structural parts used in the transportation industry can be replaced by textile-reinforced composites. Composites made from a polymeric matrix and fibrous reinforcement have been increasingly studied during the last decade. On the other hand, the fast development of smart textile structures seems to be a very promising solution for in situ structural health monitoring of composite parts. In order to optimize composites’ quality and their lifetime all the production steps have to be monitored in real time. Textile sensors embedded in the composite reinforcement and having the same mechanical properties as the yarns used to make the reinforcement exhibit actuating and sensing capabilities. This paper presents a new generation of textile fibrous sensors based on the conductive polymer complex poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) developed by an original roll to roll coating method. Conductive coating for yarn treatment was defined according to the preliminary study of percolation threshold of this polymer complex. The percolation threshold determination was based on conductive dry films’ electrical properties analysis, in order to develop highly sensitive sensors. A novel laboratory equipment was designed and produced for yarn coating to ensure effective and equally distributed coating of electroconductive polymer without distortion of textile properties. The electromechanical properties of the textile fibrous sensors confirmed their suitability for in situ structural damages detection of textile reinforced thermoplastic composites in real time.

Global and local observations of 3D warp interlock fabric behaviour during forming process

Forming behaviour of thick 3D fabric leads to unknown locations of yarns inside the 3D warp interlock structure. To check their position, global observation of painted points located at the upper surface with cameras and local measurement of the elongation of inserted sensor yarns have been done simultaneously. Depending on the fabric structure, elongations of yarn reveal the same behaviour as the global structure during the forming process.