Ultraviolet Protection Factor Research Articles

In-Situ Synthesis of CuO/TiO2 Nanocomposite Onto Amine Modified Cotton Fabric for Antibacterial Durability and UV Protection

ABSTRACT In this research work, we explore antibacterial activity and the UV-protection of cotton fabric functionalized with copper oxide-titanium dioxide nano composites particles (CuO+TiO2 NCPs). Cotton fabrics (Cot) were treated with L-methionine (Am) and functionalized with bimetallic CuO+TiO2 NCPs by pad and rolling technique. Cu(NO3)2 and titanium isopropoxide (TIP) were used as sources of Cu(OH)2 and TiO2 colloid respectively, which were then converted into CuO and TiO2 nanoparticles (NPs) for making antibacterial and UV-protective cotton. The method yielded a crystallite size of CuO and TiO2 NPs of 18.09 and 32.5 nm, respectively. FTIR, Raman spectroscopy, High-resolution scanning electron microscopy-Energy dispersive Spectroscopy (HRSEM), (EDS), X-ray photo spectroscopy (XPS), thermal gravimetric analysis (TGA), and XRD were used to analyze the functional group, morphology, chemical composition, thermal stability and crystalline structure of the functionalized cotton fabric samples. The results showed that an esterification reaction occurred between Am and OH in cotton fabric, which further enhanced the binding of NCPs. AmCot-CuO+TiO2 NCPs exhibit outstanding antibacterial activity against gram-positive S. aureus and gram-negative E. coli. The UV protection factor (UPF) for AmCot-CuO+TiO2 NCPs reached 50+; thus, multifunctional cotton fabrics with excellent antibacterial and anti-ultraviolet properties were obtained.

Development of high‐performance zinc stannate based multifunctional thermoplastic polyurethane nanocomposite films

AbstractA lot of demand exists for multifunctional TPU that can provide enhanced performance to address a variety of inflatable application needs. To develop multifunctional nanocomposite films for such uses, synthesized zinc stannate (ZnSnO3) nanoparticles are integrated for the first time in a thermoplastic polyurethane (TPU) matrix. ZnSnO3 was synthesized using hydrothermal method. The morphological analysis vividly displayed the nanocubic structures. As‐synthesized nano ZnSnO3 was added as a nanofiller at varied concentration from 2 to 10 wt% in TPU and nanocomposite films were prepared by solvent intercalation and casting method. These films were thoroughly examined for their multifunctional properties such as UV protection, helium gas barrier and infrared emissivity. Mean value of UV protection factor was improved by 75% at 10 wt% loading of ZnSnO3 whereas 23% improvement was observed in helium gas barrier. Moreover, a good correlation of experimental data with various theoretical models of gas permeability was obtained at lower volume fraction of ZnSnO3. IR emissivity value also showed improvement from 0.802 to 0.842. Thus, the developed TPU‐ZnSnO3 nanocomposite films exhibited a significant improvement in multiple functional properties with improved tensile strength at optimized loading of 6 wt% of ZnSnO3.Highlights UPF mean value of ZnSnO3 incorporated TPU film has been improved by 67%. Helium gas barrier has been improved by approximately 23% at 6 wt% loading. TPU film exhibited improved properties at optimized loading of 6 wt% of ZnSnO3. Nanocomposite TPU film can be employed in various weathering inflatables.

Evaluation of Knowledge, Attitudes and Practices on Facial Skincare Routines and Cosmetic Products in Undergraduates of Universities and Higher Educational Institutes in Western Province, Sri Lanka

Maintaining the skin's structural and functional integrity is largely dependent on proper skincare. Numerous dermatological problems can be caused by insufficient skincare techniques and inadequate information. For this reason, following an appropriate skincare routine is essential to preserving the health of the skin. The purpose of this study was to evaluate undergraduates in universities and other higher education institutions in the Western province of Sri Lanka regarding their knowledge, attitudes and practices regarding facial skincare practices. A structured questionnaire (N=255) was used in descriptive cross-sectional research of undergraduates in the Western province who were between the ages of 18 and 30. Ethical clearance was obtained from the Ethics Review Committee at CINEC Campus. There were 21.18% male participants and 78.82% female participants in the study, which included 145 undergraduates from state universities and 110 from non-state Higher Educational Institutes. The results showed that while buying face skincare products, students consider into thought several aspects, such as brand (66.27%), price (69.02%), ingredients (74.50%), expiration date (65.10%), skincare benefits (73.72%), smell (31.37%), and container (25.10%). Merely 9.42% of respondents preferred synthetic components in cosmetic products, compared to a sizable majority (90.58%) who preferred natural ones. When it came to applying sunscreen, 33.33% did it five minutes before exposure to sunlight, and 56.08% did it thirty minutes beforehand. While 34.11% of respondents knew that an optimal sunscreen in Sri Lanka should have a UV protection factor of between 30 and 50, 43.92% did not. The primary reasons given for using skincare products were to enhance appearance and texture (62.74%), prevent sunburns (54.90%), and improve skin health (76.08%). Notably, the most often used skincare items were moisturizer (48.23%) and face cleanser (82.53%). Furthermore, (67.06%) of undergraduate students chose skincare products for their faces according to their skin type; (27.45%) did it infrequently, and (5.10%) never gave it any thought. The study revealed that some undergraduates lack accurate awareness about skincare routines, indicating a need for additional knowledge in this area.

Synthesis, physicochemical, nonlinear optical properties of azonaphtharylmide dyes: Dyeing and UV-protection performance on wool, silk, polyester

This study focuses on the synthesis and characterization of three azonaphtharylmide dyes, APAS, APASD, and APASTR, using naphthol AS, ASD, and ASTR couplers. The research also observes the presence of a hydrazone tautomer in a DMSO solution. It was characterized through spectroscopic analysis, which revealed three characteristic carbonyl carbon peaks in the 13C NMR spectrum. The calculated low LUMOs (−3.46 eV to −3.54 eV) align closely with experimental calculations (−3.45 eV to −3.48 eV), indicating the potential of these dyes as electron acceptors. Furthermore, the alignment of frontier molecular orbital (FMO) values supports their suitability for electron acceptance. When applied to wool, silk, and polyester materials, these dyes confer UV protection properties, with wool-dyed fabrics achieving a UV Protection Factor (UPF) of 50+. Additionally, these dyes exhibit significantly improved nonlinear optical responses, with beta (β0) values ranging from 11 × 10−30 to 23 × 10−30 esu and gamma (γ0) values ranging from 275 × 10−36 to 365 × 10−36 esu, indicating their functionality as nonlinear optical materials.

Modification of sericin using cyanuric chloride and its application on the textile substrate to impart multifunctional properties

Sericin is a highly hydrophilic macromolecular protein comprising 18 amino acids. It is considered biocompatible, nontoxic, and has antibacterial and antioxidant properties. It is applied on fabric, however, either the fabric needs to be pretreated with electrolytes or catalyst are used thereby increasing the number of processing steps. This study achieved sericin with multifunctional properties through chemical modification using cyanuric chloride. Modified sericin was applied in the dyeing stage along with the dyes on various textile substrates like wool, silk, and polyester. The functional properties were characterized by Fourier transform infrared and in modified sericin new chlorine peak at 779 cm−1 was obtained, X-ray diffractogram shows increase in crystallinity after modification of sericin, SEM showed particles of sericin on all fabrics even after 5 washes. Fabrics were analysed for antimicrobial activity and showed antimicrobial properties against gram negative and positive bacteria. Fastness properties and ultra violet protection factor of the samples were also determined.

Dyeing of Cotton and Wool Fibers with the Aqueous Extract of Alnus glutinosa: Evaluation of Their Ultraviolet Protection Factor, Their Color fastness and the Antioxidant Activity of the Aqueous Extract

The aim of the present study is to evaluate the dyeing properties and behavior of the aqueous extract of Alnus glutinosa leaves when applied on cotton and wool fibers. The antioxidant activity and the total phenolic content of the aqueous extract were calculated. The colorfastness of the dyed samples such as washing, acid and alkali perspiration, wet and dry fastness and light fastness was performed. The ultraviolet protection factor (UPF) which is a measurement of the protection offered by the dyed fabric substrates against ultraviolet radiation was also assessed. It was found that Alnus glutinosa aqueous extract shows exceptionally high antioxidant activity and high phenolic content. The dyed samples showed astonishingly high light fastness approaching the light fastness of synthetic dyes such as the vat dyes or metal complex dyes. The conferred protection of the dyed samples against the distractive ultraviolet radiation is exceptionally high as this is demonstrated by the high UPF measurements of the dyed samples.

Multifunctional ammonium polyphosphate coated cotton fabric for flame retardant, anti-wrinkle, ultraviolet protection and anti-bacterial

The multifunctional cotton fabrics, which were expected to become one of the most promising textile materials, gained much attention in the apparel market. In this work, the simultaneous coloration and finishing processes with natural dye were carried out to prepare the multifunctional cotton fabrics. The modification process using ammonium polyphosphate (APP) imparted the cotton fabric with numerous anionic sites along with flame retardant and anti-wrinkle properties. Subsequently, the implementation of coloration with berberine was to render the cotton fabric with elegant shade and anti-bacterial, ultraviolet (UV) protection performances. The obtained results revealed that the cotton fabric treated with APP could obtain deep shade. It was found that the limited oxygen index (LOI), wrinkle recovery angle (WRA), ultraviolet protection factor (UPF) and antibacterial efficiency of treated fabric were 46.4%, 252°, 193 and 99%, respectively. More importantly, the repeated laundering showed negligible influence on the flame retardant and anti-wrinkle performances. In addition, the anti-bacterial and UV protection performance of treated cotton fabric exhibited a slight decline even after 20 cycles of washing. Finally, the washing and rubbing fastness of obtained cotton fabric were also desirable.

Effect of polycarbodiimide, epoxy chain extenders and tannic acid on the hydrolysis and UV resistance of polylactic acid

Polylactic acid (PLA) possesses characteristics such as biodegradability, ease of processing, and environmental friendliness, making it an ideal alternative to petroleum-based polymers. However, PLA has drawbacks such as susceptibility to hydrolysis and sensitivity to ultraviolet (UV) light, limiting its application in certain areas. In this study, poly(carbazole diimide) (PCDI) and the epoxy chain extender Joncryl ADR4468 (CE) were employed as a synergistic anti-hydrolysis agent for PLA, and tannic acid (TA) was used as a UV-resistant agent. A melt-blending process was employed to prepare PLA composite materials with enhanced resistance to both hydrolysis and UV radiation. The results indicate that the addition of PCDI-TA-CE significantly improved the performance of PLA. After 8 h of hydrolysis at 80 °C, the tensile strength of PLA increased from 38.31 MPa for pure PLA to 77.69 MPa with the incorporation of PCDI-TA-CE. The elongation at break increased from 0.6% to 1.5%, and the Ultraviolet Protection Factor (UPF) value elevated from 3.19 for pure PLA to 503.46.This demonstrates that PCDI, CE, and TA can effectively enhance the anti-hydrolysis and UV resistance properties of PLA.

Large-scale and green preparation of multifunctional ZnO

Highly active and multifunctional zinc oxide (ZnO) was synthesized using the water bath method. The concentrated NaOH solution rapidly converted zinc ions to ZnO. The solvent was then recycled multiple times after separating from the ZnO product, and the crude sodium sulfate by-product was precipitated through crystallization at room temperature. The entire recycling process produces no pollutant emissions and yields an average of 86.13 % zinc, achieving a green and efficient synthesis of ZnO. Xenon (Xe) radiation increases oxygen vacancies in ZnO, enhancing gas sensing. The sample S3 of ZnO sensors was obtained by xenon lamp irradiation for 9 h showing a 2.4 times higher response to 100 ppm NO2 at 90 ℃ (653.12) compared to the sample S0 of ZnO sensors without xenon lamp irradiation. Moreover, ZnO has excellent UV absorption in the wavelength range of 290–380 nm. By impregnating cotton fabrics with ZnO materials, the UV protection factor (UPF) of cotton textiles was increased from 4 to 33.

Functionalization of wool fabric by rice stubble extract dyeing and bio-mordanting

In this research, rice stubble, an air-polluting agricultural waste after burning the current years, was considered to explore a sustainable application in rice-growing countries. The rice stubble extract was used to dye and functionalize the wool fabric. The dyed woollen fabrics were thoroughly characterized concerning their physical, chemical and comfort properties by scanning electron microscope (SEM), thermogravimetric analysis (TGA), Fourier transform infrared (FTIR) spectroscopy, water vapor transmission rate (WVTR), and ultraviolet protection factor (UPF). The color characteristics, color fastness against the woollen fabrics, and flame retardancy were also assessed. The results revealed that the rice stubble extract has a coloring chromophore to offer bright shades with considerable fastness abilities. The rice stubble-dyed woollen fabrics showed considerable water vapor permeability, efficient UV shielding, and adequate flame Retardancy. The dyed woollen fabrics showed a maximum water vapor permeability of 2500 g/m2/24h, ultraviolet shielding of 350, and a limiting oxygen index of 30.

Design, Synthesis, Characterization, and Antimicrobial Properties of New Azo Disperse Dyes Incorporating Quinazolinone-Pyrazolone Moieties and Their Applications for Dyeing of Polyester Fabrics

The current study outlines a straightforward and efficient method for creating new quinazolinone disperse dyes based on pyrazolone moieties, starting with quinazolinone and a variety of substituted pyrazolone as couplers. The synthesized dyes were characterized using a variety of spectroscopic and analytical methods. The synthesized dyes' ultraviolet–visible spectra showed bands brought on by several molecular transitions. We investigated in detail the multifunctional characteristics such color representation, dyeing duration, concentration, pH, buildup, and fastness properties of the dyed samples. Fastness properties and colorimetric data showed satisfactory results, demonstrating the effectiveness of these dyes in dyeing polyester fabrics. A pH of 5 and a dyeing temperature of 130 °C were the ideal conditions for dyeing polyester fabrics. Additionally, an ultraviolet protection factor test was performed on the dyed fabrics, and the results showed that these dyes provide the best UV protection. These dyes are suitable for industrial dyeing applications since they are easy to manufacture and scale up. Additionally, in-vitro testing was done to determine the dyes' antibacterial effectiveness against various bacteria and fungi. The antibacterial activity of the dyes was moderate to very good against both Gram-positive and Gram-negative bacteria, as well as fungi.

A durable, breathable, and weather-adaptive coating driven by particle self-assembly for radiative cooling and energy harvesting

The imperative to attain net-zero emissions emphasizes energy conservation. Radiative cooling stands out as a compelling technology in this pursuit for its self-sufficiency and cost-effectiveness. However, the radiative cooling faces the challenge in varied weather, including high ultraviolet (UV), cloudy and rainy days, primarily due to instability of radiative cooling materials and mono-energy conservation mechanism. To address this issue, a durable, breathable, and weather-adaptive coating (porous PTFE coating) has been developed through assembling polyfluortetraethylene (PTFE) nanoparticles enabled by the differential interaction in a binary-solvent system. The porous PTFE coating exhibits high solar reflectivity (94%) and thermal emissivity (93%), which results from the precisely tunable assembly of PTFE nanoparticles, forming a desired porous morphology. This design serves as effective scattering, achieving a sub-ambient cooling effect of approximately 5 ℃ at midday. With an outstanding UV protection factor (UPF) of 179.15, the porous PTFE coating sustained stability after 40 days exposure to solar radiation. Leveraging the porous PTFE coating's exceptional negative triboelectric effect, an engineered high-performance droplet electricity nanogenerator (DEG) achieves a notable power density of 153.8 mW/m2, revealing significant potential for raindrop energy harvesting on rainy days. The versatile porous PTFE coating, with its exceptional weather adaptation and UV stability, holds promise for diverse applications, advancing sustainable and efficient energy solutions with reliability in varying conditions.

Natural cellulosic biofunctional textiles from onion (Allium cepa L.) skin extracts: A sustainable strategy for skin protection

Cellulosic fabrics made of cotton, linen, bamboo, hemp, and nettle, were selected for the eco-sustainable production of colored biofunctional textiles, using natural dyes from onion skin of the Dorata di Parma (Allium cepa L.) variety. Dyeing experiments were performed in net water with and without pre-treatment with alum, tin chloride, and tannic acid as mordants. The color and the UV-protection factor (UPF) were evaluated through UV–visible spectroscopy. The treatment with onion skin extract induced a relevant increase of UPF in all investigated fabrics, promoting the protection category from insufficient (UPF<15) to good for linen (UPF = 21–26), up to very good and excellent for cotton (UPF = 35–66) and bamboo (UPF = 48–56), respectively. To mimic the direct contact with the skin, textile samples were immersed in artificial sweat where dyed cotton, hemp, and nettle were found to promote higher phenolic release (0.28–0.50 mg gallic acid equivalents/g textile) than linen and bamboo (0.12–0.22 mg gallic acid equivalents/g textile). The obtained “biofunctional sweat” did not impact on the survival of primary human dermal fibroblasts (HDF) and skin keratinocytes (NCTC2455), while protected these cells against heat shock and reduced reactive oxygen species levels upon exposure to pro-oxidant and inflammatory agents as H2O2 and lipopolysaccharide, respectively. Increased activity levels of the H2O2-scavenging enzyme Catalase (CAT) were also observed, thus demonstrating enhanced stress response and homeostatic capability of these cells. This study provides evidence that extracts from onion waste can be used to functionalize cellulosic fabrics conferring properties as natural shield against UV radiation, and antioxidant and anti-inflammatory materials thus holding potential in skin protection and prevention of dermatological diseases.

Enhancing polyamide fabric performance through green reduction of graphene oxide for superior ultraviolet protection and electrical conductivity

AbstractIn this study, a polyamide warp‐knitted fabric was treated with a graphene oxide (GO) aqueous dispersion using a laboratory‐type Jigger dyeing machine. Subsequently, the GO underwent a chemical reduction process, employing rosehip extract powder as a nature‐based reducing agent. The effect of reduction time (12 and 24 h) was investigated. The study involved an examination of the surface morphology, colour coordinates, and colour difference of both the GO coated and reduced graphene oxide (RGO) coated fabrics. Additionally, the colour fastness against rubbing was assessed. Furthermore, electrical resistivity measurements were conducted on the GO‐coated polyamide‐6,6 fabric both before and after the reduction process. The ultraviolet (UV) transmittance and ultraviolet protection factor (UPF) of both GO‐coated and reduced fabrics were determined. The study also explored the effect of the washing process on colour properties, electrical resistivity, and UPF. Notably, the lowest electrical surface resistivity and the highest UPF rating were obtained as 1.20 × 102 kΩ/sq and 50+ after the reduction process. Additionally, after the washing process, the electrical surface resistivity increased, while the UPF rating remained 50+, indicating excellent UV protection.

Thermal-based Zinc-Oxide-Coated Smart Fabric for Thermochromic Applications

The present study focuses on developing a thermochromic device with a flexible substrate through the coating of cotton fabric with ZnO (Zinc oxide) by solvothermal synthesis technique. Here, ZnO is used as the thermochromic layer for the fabrication work, and it is suitable for textile and wearable applications as it is non-toxic to human skin. This device is designed and fabricated in order to gain better insight into the role of ZnO in thermochromic applications. Here, 3D nanostructures of ZnO are grown on the surface of cotton fabric using a simple and cost-effective solvothermal synthesis approach. The coated fabrics are investigated to determine their structure, morphology, composition, electrical, optical and emissivity properties using an X-ray diffraction (XRD), field-emission scanning electron microscope (FE-SEM), current-voltage (I-V) characteristics, ultraviolet protection factor (UPF) etc. From the morphology study, uniformly packed ZnO nanorods with growth in the c-axis direction are observed. The ZnO nanostructures are known to have excellent UPF when exposed to solar radiation and showed UPF value of 112.48. It is found that coated fabrics have increased electrical conductivity under optical excitations and also enhanced the reflectance. Moreover, based on the emissivity analysis coated ZnO cotton fabric showed the emissivity of 0.95, which is higher and has greater radiation protection than that of bare cotton fabric. Hence, the developed thermochromic device has potential for use in the future in textile and wearable based thermochromic application.

Physicochemical and photocatalytic properties of biogenic ZnO and its chitosan nanocomposites for UV-protection and antibacterial activity on coated textiles

The textiles for medical use and the purification of textile factory effluents have become the most crucial part of the human healthcare sector. In this study bioactive compounds produced by four distinct plant extracts were used for the synthesis of zinc oxide nanoparticles. The four different ZnO nanoparticles were comprehensively characterized by different analytical techniques. XRD analysis revealed the crystalline nature and phase purity of the ZnO nanoparticles. FTIR spectra provided information on the function of plant extracts in the stabilization or capping process. The size distribution and morphological diversity of the nanoparticles were further clarified by SEM and TEM images. The photocatalytic degradation activity of the four ZnO nanoparticles on two different dyes showed that ZnO nanoparticles prepared from A. indica were most effective for the degradation of 98 % and 91 % of Rhodamine B and Alizarin red dye respectively. The selected ZnO nanoparticles from A. indica were used to prepare ZnO-chitosan nanocomposites before coating on cotton fabrics. The hydrophobicity, UV protection factor, and antibacterial activity of ZnO-chitosan nanocomposites, when coated on cotton fabrics, were also examined. The overall results demonstrated the ZnO and ZnO-chitosan nanocomposite prepared in the present study as a promising material for environmental remediation application.

Green encapsulation of textile dyes using lecithin to increase dyeing performance

Purpose The purpose of this study is to use liposome technology in the treatment of fabrics textiles because of its efficient energy saving, reducing time and temperature. Design/methodology/approach The newly prepared lecithin liposome was used to encapsulate dyes for the purpose of increasing dyeing affinity. Different ratios of commercially available lecithin liposomes (1%, 3%, 5% and 7%) were used simultaneously in the dyeing of cotton and wool fabrics. The treated fabrics (cotton and wool fabrics) were confirmed using different analytical procedures such as scanning electron microscope (SEM), Fourier-transition infrared spectroscopy, ultraviolet protection factor, colour strength (K|S) measurements and fastness measurements. Findings The results show that increasing liposome ratios in dyeing baths leads to increased dyeing affinity for cotton and wool fabrics compared with conventional dyeing without using liposomes. In addition to that, the colour strength values, infrared spectra, SEM and fastness properties of non-liposome-dyed fabrics and liposome-dyed fabrics were investigated. Originality/value The research paper provides broad spectrum of green encapsulation fabrics using liposome technology to perform the dye stability, dye strength and fastness.

Ultraviolet resistance on weft knitted fabric coated by benzotriazoles

Ultraviolet resistance upon four different types of weft knitted fabrics including Lacoste, Single Jersey, Rib and Interlock were experimentally measured and evaluated by ultraviolet–visible spectroscopy under effects of gauge, specific weight, fiber composition and finishing agent as benzotriazole derivatives. The results showed that ultraviolet protection factor (UPF) of Interlock sample reached the highest value at 42.7. Simultaneously, the higher gauge of Single Jersey knitted fabrics was, the better its ultraviolet protection exhibited. Also, insertion of polyester fibers or spandex fibers into cotton knitted fabrics with a certain ratio strongly increased UPF values. Notably, all UPFs of coated fabrics with a given content of benzotriazole were significantly improved and almost coated samples could undergo several washing cycles and still retain their inherent breathability. This work demonstrated that cotton knitted fabrics coated with benzotriazoles were excellently enhanced ultraviolet protection. Especially, the UPF values on Interlock or Rib specimens as well as Single Jersey samples blended with polyester/spandex fibers were found to be higher than 15.

Flavonoid‐based yellow dye extract from safflower (Carthamus tinctorius L.) combined with chitosan for anti‐bacterial and ultraviolet‐protective functionalisation of silk

AbstractIn the modern period, scientists are interested in the functional properties of natural materials. The present study is the first report on the use of safflower (Carthamus tinctorius L.) yellow dye extract combined with chitosan bio‐mordant for enhancing the anti‐bacterial and ultraviolet‐protective activities of silk. The presence of flavonoid‐based compounds in the dye extract was verified using liquid chromatography–mass spectrometry, Fourier transform‐infrared spectroscopy, and ultraviolet‐visible techniques. Moreover, alum mordant was also utilised in the silk dyeing process to compare the efficiency of bio and metallic mordanting agents. Experiment outcomes revealed that the chitosan mordanted‐dyed silk sustained adequate fastness after being tested by washing, light, wet‐rubbing, and dry‐rubbing. In addition, superb bacterial inhibition percentages of 89% and 76% against Escherichia coli and Staphylococcus aureus, individually, were accomplished. Furthermore, the ultraviolet‐protective behaviour of this silk sample was demonstrated with a 50+ ultraviolet protection factor and low‐grade ultraviolet transmittance. This study reveals the great performance of an organic flavonoid dye as a sustainable and environmentally‐friendly substance for dyeing and functionalising silk, as well as the efficacy of a green mordant over a metallic mordant in increasing the dyeability and functional activities of silk.

The Influence of Titanium Dioxide (TiO2) Particle Size and Crystalline Form on the Microstructure and UV Protection Factor of Polyester Substrates.

The inclusion of particles in a polymeric substrate to achieve certain properties is a well-known practice. In the case of textile substrates, this practice may deeply affect the structure of the produced yarns, as even a filament with no textile applications can be obtained. In this manuscript, titanium dioxide (TiO2) particles were incorporated into polyester (PET) chips and the influence of these fillers on the properties of yarn and fabric, and the ultraviolet protection factor (UPF) was assessed. For this purpose, rutile and anatase crystalline forms of TiO2, as well as the size of the particles, were evaluated. Moreover, parameters such as mechanical properties, orientation of the macromolecules and thermal behavior were analyzed to ensure that the textile grade is maintained throughout the production process. The results showed that the inclusion of micro- and nanoparticles of TiO2 decreases the molecular weight and tenacity of PET. Also, although orientation and crystallinity varied during the textile process, the resulting heatset fabrics did not present important differences in those parameters. Finally, the attainment of textile-grade PET-TiO2 fabrics with UPF indexes of 50+ with both rutile and anatase and micro- and nano-sized TiO2 forms was demonstrated.