Hair Fibers Research Articles

A combined scattering and diffraction model for elliptical hair rendering

AbstractRealistic hair rendering relies on fiber scattering models. These models are based on either ray tracing or on full wave‐propagation through the hair fiber. Ray tracing can model most of the scattering phenomenon observed but misses the important effect of diffraction. Indeed human natural hair specific dimensions and geometry demands for the wave nature of light to be taken into consideration for accurate rendering. However, current full‐wave model requires nonpratical, several days precomputation, that needs to be repeated for every change in the hair geometry or color, for appropriate results. We present in this paper a dual hair scattering model which considers the dual aspect of light: as a wave and as a ray. Our model accurately simulates both diffraction and scattering phenomena without requiring any precomputation. Furthermore, it can simulate light transport in hairs of arbitrary elliptical cross‐sections. This new dual approach enables our model to significantly improve the appearance of rendered hair and qualitatively match scattering and diffraction effects seen in photos of real hair while adding little computation overhead.

Exceptional ancient DNA preservation and fibre remains of a Sasanian saltmine sheep mummy in Chehrābād, Iran.

Mummified remains have long attracted interest as a potential source of ancient DNA. However, mummification is a rare process that requires an anhydrous environment to rapidly dehydrate and preserve tissue before complete decomposition occurs. We present the whole-genome sequences (3.94 X) of an approximately 1600-year-old naturally mummified sheep recovered from Chehrābād, a salt mine in northwestern Iran. Comparative analyses of published ancient sequences revealed the remarkable DNA integrity of this mummy. Hallmarks of postmortem damage, fragmentation and hydrolytic deamination are substantially reduced, likely owing to the high salinity of this taphonomic environment. Metagenomic analyses reflect the profound influence of high-salt content on decomposition; its microbial profile is predominated by halophilic archaea and bacteria, possibly contributing to the remarkable preservation of the sample. Applying population genomic analyses, we find clustering of this sheep with Southwest Asian modern breeds, suggesting ancestry continuity. Genotyping of a locus influencing the woolly phenotype showed the presence of an ancestral ‘hairy’ allele, consistent with hair fibre imaging. This, along with derived alleles associated with the fat-tail phenotype, provides genetic evidence that Sasanian-period Iranians maintained specialized sheep flocks for different uses, with the ‘hairy’, ‘fat-tailed’-genotyped sheep likely kept by the rural community of Chehrābād's miners.

Effect of fiber hybridization on mechanical, thermal, and water absorption behavior of HF/CF/HDPE composites

The composite materials are present in nature since the prehistoric era. Applications of fiber-based composite materials are increasing day by day in our society to overcome the raised environmental and economic concerns. Hence, waste fiber can be utilized as the best resource to develop composites. The present study deals with the impact of hybridization on the mechanical, thermal, and water absorption behavior of hair and coir fiber-based hybrid composites. The compression molding technique was used to develop the hybrid composites with fixed fiber content (15 wt.%) and was also varied the relative weight percentage of hair and coir fibers [(100% HF), (75% HF/25% CF), (50% HF/50% CF), (25% HF/75% CF) and (100% CF)] in reinforcing phase with HDPE composites S1, S2, S3, S4, and S5, respectively. The composite S2 was achieved superior mechanical attributes as compared to other hybrid/non-hybrid composites. The composite S2 was improved the tensile strength 5% and 35.2% more in comparison to composites S1 and S5, respectively. The thermal behavior (TGA, DTG, and DTA) was also influenced by the blending ratio of fibers of composites. The 5% and 50% weight losses of composite S2 were observed at higher temperature 343.8°C and 465.8°C as compare to other composites, which showed the thermal stability of composites S2. SEM analysis was used to investigate the strength of the fiber-matrix interface, which was shown a significant connection between mechanical and thermal behaviors. The crystallinity of hybrid and non-hybrid composites was examined by using the X-ray diffraction (XRD) analyzer and composite S2 was achieved 326 × 10−9 m crystal size at 21.053° peak position with wavelength 1.5406 × 10−10 m for Cu. The water absorption test was used to examine the moisture resistivity of composite materials, which was helpful to increase the applications of materials in humid areas.

Organoleptic and physicochemical properties of natural-based herbal shampoo formulations with Cyclea peltata as a key ingredient.

Synthetic shampoos have toxic chemical agents like chemicals such as parabens and sodium lauryl sulfate which damage the hair. To combat this issue, the use of natural herbal shampoos, as opposed to synthetic shampoos, is becoming increasingly popular. One of the many medicinal plants present in Karnataka and Kerala is Cyclea peltata. This plant has long been known to assist in wound healing, allergy relief, and hair and scalp improvement, as well as serving as a coolant for hair applications. The key subject of this research was the preparation of plant extracts and fermentation of Cyclea peltata leaf extract with Lactobacillus plantarum, resulting in the formulation of an herbal shampoo. The leaf extract contained alkaloids, flavonoids, tannins, phenolic acid, saponins, and proteins, according to previous research by this group. The fermented product showed the presence of lactic acid, which was a boon for shampoo base as it protects the hair from the sunlight and improves the texture and strength of hair fibers. Cyclea peltata was used as the main ingredient in herbal shampoo formulations, along with other herbal ingredients, and the formulated shampoo was characterized for its different organoleptic (Color, odor) and physicochemical properties (pH, solid content, wettability, emulsification, and foam stability) to find the best formulation. Formulation H2 showed better organoleptic and physicochemical properties and thus was chosen as the best formulation among the 11 formulations. Formulation H2 is regarded as the best formulation based on the results of the physicochemical tests (Pleasant odor, pH 3.01, solid content of 5.75%, wettability of 1.68s, and percentage emulsification of 68.75%).

High-throughput phenotyping methods for quantifying hair fiber morphology

Quantifying the continuous variation in human scalp hair morphology is of interest to anthropologists, geneticists, dermatologists and forensic scientists, but existing methods for studying hair form are time-consuming and not widely used. Here, we present a high-throughput sample preparation protocol for the imaging of both longitudinal (curvature) and cross-sectional scalp hair morphology. Additionally, we describe and validate a new Python package designed to process longitudinal and cross-sectional hair images, segment them, and provide measurements of interest. Lastly, we apply our methods to an admixed African-European sample (n = 140), demonstrating the benefit of quantifying hair morphology over classification, and providing evidence that the relationship between cross-sectional morphology and curvature may be an artefact of population stratification rather than a causal link.

Thermal behavior and dielectric response of epoxy–boron nitride composites reinforced with short human hair fiber

AbstractPolymer composites with low dielectric constant and high thermal conductivity are gaining considerable attention due to their rising demand in various microelectronic applications such as printed circuit boards, connectors, encapsulations, and electrical contacts. In the present investigation, thermal and dielectric properties of a new class of epoxy‐based hybridized composites with improved thermal conductivity (k), high glass transition temperature (Tg), low coefficient of thermal expansion (CTE), controlled dielectric constant (Dk), and low dielectric loss (DL) have been reported. Epoxy‐based composites are fabricated by solution casting method with various wt% (0, 5, 10, 15, and 20 wt%) of short hair fiber and with a fixed proportion of micro‐sized boron nitride (BN) (10 wt%) particles. Effects of fiber content on different thermal properties of the composites such as effective thermal conductivity (k), CTE, and Tg are studied by conducting tests as per appropriate American Society for Testing and Materials (ASTM) standards. Dielectric properties of the composite samples such as dielectric constant (Dk) and dielectric loss (DL) are evaluated in a HIOKI‐3532‐50 Hi Tester Elsier Analyzer. It is observed that with the addition of BN, thermal conductivity of the hybrid composite has significantly improved whereas the dielectric constant of the composite shows a decreasing trend with the increase in fiber content and operating frequency. There is also a marked improvement in the glass transition temperature of epoxy with the incorporation of short human hair fibers.

Proteins as Hair Styling Agents

The perming of hair is a common styling procedure with negative impact on the overall properties of the hair fibers. Usually, this process uses harsh chemicals to promote the disruption of disulfide bonds and the formation of new bonds to change the shape of hair. Here, we explored bovine serum albumin (BSA), silk fibroin (SF), keratin and two fusion recombinant proteins (KP-UM and KP-Cryst) as new perming agents. A phosphate buffer prepared at different pH values (5, 7 and 9) was used to apply the proteins to virgin Asian hair, and a hot BaByliss was used to curl the hair fibers. To assess the potential of the protein formulations for hair styling, the perming efficiency and the perming resistance to wash were measured. Furthermore, the fiber water content was evaluated to assess if the proteins protected the hair during the styling process. Despite all of the proteins being able to assist in the curling of Asian hair, the best perming efficiency and perming resistance to wash results were observed for BSA and keratin. These proteins showed perming efficiency values close to that measured for a commercial perming product (chemical method), particularly at pH 5 and 9. The increase in the hair’s internal and external water contents revealed a protective effect provided by the proteins during the application of heat in the styling procedure. This study shows the potential of proteins to be used in the development of new eco-friendly hair styling products.

Prevention of chemically induced hair damage by means of treatment based on proteins and polysaccharides.

There is currently a great interest not only in developing products for the protection and recovery of chemically damaged hair, but also in developing effective protocols to investigate the impact of chemical treatments and attest the efficacy of innovative hair care products. Among the most relevant cosmetic treatments for hair are bleaching and coloring, which have been shown to significantly impair mechanical and structural properties. This study aimed to characterize the damage induced by hair bleaching and coloring and to evaluate the protective effects of a hair care treatment based on integral silk proteins (fibroin and sericin) and vegetable-derived polysaccharides from linseed (Linum usitatissimum L.). Hair swatches were subjected to different treatment protocols in order to evaluate the protective effect of proposed and benchmark products during bleaching and coloring processes. Tensile tests were performed to assess mechanical properties and improvement in resistance to breakage. Goniophotometric measurements were applied to determine improvement in luster. Hair fiber surface and relief were evaluated by SEM image analysis. Swatches bleached and treated with both evaluated products had a significant increase in resistance and reduced structural damage. Swatches colored and treated with both evaluated products showed reduced structural damage, and a significant increase in resistance and luster after the 1st and 5th washes. The proposed product was effective in protecting and repairing bleached and colored swatches, improving resistance and luster and reducing structural damage. By applying complementary techniques within a reliable evaluation protocol, it was possible to attest the protective properties of the product under study.

Fabrication and characterization of eco-friendly composite materials from natural animal fibers

A large amount of useless portion, which is discharging from leather industries, pollutes the environment immensely. The discarded part needs to be recycled to yield other valuable products to subside environmental pollution. In this research, we utilized a rejected part (cow hair) of leather industries and unsaturated polyester resin (UPR) to fabricate valued composites to confine atmospheric pollution. A hand-lay-up technique, which is an easy and economical approach, was employed for composites fabrication. A number of cow hair fiber percentages (2, 5, 7, 10, 12, 15, and 20% by weight) were taken into consideration to investigate the impact of fiber loading on composites. Prepared composites were characterized by a few mechanical properties such as tensile strength (TS), tensile modulus (TM), elongation at break (EB), bending strength (BS), and bending modulus (BM). Fourier Transform Infrared (FTIR), Electron Scanning Microscopy (SEM), and water absorption were also performed to support the data in favor of mechanical properties. Optimum mechanical properties which were supported by the other analysis were achieved for 5% cow hair containing composites.

The Effect Of Adding Latex And Hair Fiber On Concrete

Along with the development of the construction world, the need for concrete is increasing and the scale of development shows that there will also be more and more concrete needs in the future, thus affecting the development of concrete technology which will demand new innovations regarding the concrete itself. In the construction of high-rise buildings required concrete with high compressive strength. However, to get good quality concrete, high costs are also required. So in this study, an economical additional material will be used which will be added to the concrete in the form of latex and hair fiber.
 Testing of materials and test objects is carried out in accordance with the applicable Indonesian National Standard (SNI). The latex used is liquid latex. First, the hair fiber is washed in order to clean the dirt and debris attached and then dried in the sun for 2 days, then cut to a size of ± 30 mm. By adding latex with variations of 0.25%, 0.5% and 0.75% it is expected to achieve a concrete quality of 20 MPa and by adding 2% hair fiber and latex with variations of 0.25%, 0.5% and 0.75% is expected to achieve a concrete quality of 20 MPa. The research object used a cylinder with a diameter of 15 cm and a height of 30 cm with the addition of 48 pieces of latex which were tested at the age of 28 days, cylinder with a diameter of 15 cm and a height of 30 cm with the addition of latex and hair fiber as many as 18 pieces were tested at the age of 7 days, and a beam without reinforcement with a length of 60 cm, width 15 cm and height of 15 cm with the addition of latex and hair fiber as much as 3 pieces The Water Cement Factor (FAS) in this study was locked at 0.5. This study was intended to obtain the value of compressive strength, split tensile strength, concrete absorption, slump value in cylinders and flexural strength values ​​in unreinforced beams. From the test results, it was found that the slump value decreased due to the addition of the latex additive and increased due to the addition of the latex and hair fiber additives and then increased along with the increase in the additional variation. The absorption of concrete also decreased with the addition of the latex additive and increased with the addition of the latex additive and hair fiber. The most optimum compressive strength results were obtained in concrete with the addition of 0.75% latex variation, an increase of 13.226% from normal concrete while the most optimum compressive strength results were obtained in concrete with the addition of 0.75% latex variation and 2% hair fiber reduced by 0.94% from normal concrete.

584 Transcriptomic analysis to identify protective dermal papilla signature in occipital scalp

Androgenetic alopecia (AGA) is defined by the miniaturization of hair follicles (HF) on the frontal (F) scalp, while occipital (O) HF are spared. Miniaturization is characterized by both thinning of the hair fiber and a decrease in cell number within the HF dermal papilla (DP). While previous research has looked at differences in HF stem cells between miniaturizing and growing HF in humans, to our knowledge no groups have looked at differences in the ex vivo DP between the F and O sites. Since the DP in FHF is affected by miniaturization, we hypothesized that a unique transcriptional signature in the ODP protects them from miniaturization. To investigate this, we carried out unbiased transcriptomic profiling of patient-matched DP and dermal sheath (DS) from FHF and OHF from 4 males undergoing hair transplantation surgery. By cross comparing, we identified 16 genes that are expressed at significantly higher levels in the ODP, compared to these 3 other dermal cell types. We believe this ODP signature protects DP from size reduction and cell loss during transition through the hair cycle, and thus protects OHF from miniaturization. Genes, previously identified as core DP genes, such as HHIP and SOSTDC1 were present in the unique ODP signature. Previous research using a murine patch assay to assess inductivity has shown that cultured FDP are significantly less inductive than cultured ODP. To interrogate the roles of ODP signature genes and evaluate their protective role against AGA, we developed an animal-free model of inductivity for high throughput analysis. When ODP cells are combined with epidermal keratinocytes (KC), cells self-organize into organoid structures with an ODP core, surrounded by KC. The KC in this model expresses a hair differentiation marker, K75 at significantly higher levels compared to organoids with a non-follicular fibroblast core, suggesting DP-induced KC reprogramming. We are now using this model to assess how ODP signature genes contribute to the KC reprogramming ability of DP organoids.

Plant Oil-based Nanoemulsions: Preparation and Efficacy for Hair Treatment

Background::The use of polymers in hair care products is widespread, and silicones in particular, are extensively used in cosmetic formulations. In addition, plant oils can also be used for hair treatment.Objective:n the present work, oil-in-water (O/W) nanoemulsions were prepared to repair chemical damage to human hair samples, to investigate the combined use of a silicone polyether copolymer (surfactant) that has a branch composed of poly(ethylene oxide) in its chains, and two types of plant oils: coconut and ojon oil.Materials and Methods::Surfactant-oil-water formulations were obtained by ultrasonic processing. The nanoemulsions were then applied to human hair strands previously damaged with sodium hydroxide, to compare the treated strands with untreated ones. The efficacy of the formulations was investigated by scanning electron microscopy, thermogravimetric analysis and mechanical tests.Results and Discussion::Stables nanoemulsions were obtained with average size of the dispersed droplets up to 400 nm. The micrographs suggest that the action mechanism of the nanoemulsions depends not only on the type of plant oil used and on size of the droplets dispersed in the system, but also on the type of hair that receives the treatment. The thermal analysis showed that the use of nanoemulsion changed the temperature of keratin interconversion to higher values, which can make hair fibers more resistant to heat. Hair resistance was improved when comparing virgin samples to the damaged ones.Conclusion::The nanoemulsions were efficient in the treatment of the hair samples, which showed a significant improvement in their mechanical properties.

Identification by Medulla Patterns of Animal Hair and Animal Fiber as Forensic Evidences

Identification by Medulla Patterns of Animal Hair and Animal Fiber as Forensic Evidences

Tribological Properties between Taut Hair Fibers in Wet Conditions: A New Shampoo Formulation for Eliminating Stick‐Slip Friction

AbstractThe tribological properties between taut hair fibers in wet conditions were investigated to evaluate the tangling/detangling performance of shampoo formulations during washing (particularly rinsing). A new setup for friction measurements between taut hair fibers was established. Using the setup, tribological properties of hair fibers treated with two shampoo formulations, whose tangling performances were different, were investigated. The base formulation for the shampoos was the same; the only difference was the type of amino‐modified silicones used as conditioning agents. Shampoo (Sp) A (poor detangling performance) incudes water‐insoluble silicone, and Sp B (excellent detangling performance) includes water‐soluble silicone. The tribological behaviors between taut hair fibers treated with the diluted solutions of the Sp were very different; the Sp A‐treated hair exhibited stick‐slip sliding, whereas the Sp B‐treated hair exhibited smooth sliding. This difference presumably comes from the different coacervation behaviors in the diluted solutions and resulting structure of conditioning film formed on hair surfaces. The smooth sliding (ideal for detangling) of Sp B‐treated hair comes from the two‐layer structure of the conditioning film on hair; positively charged amino‐modified silicone dissolved in water adsorbed immediately on negatively charged hair surface, followed by the physical adsorption of coacervates on the adsorbed silicone layer. The outer coacervate layer is easily removed during sliding, and smooth sliding comes from the low friction of the silicone layer. The relationship between the type of amino‐modified silicones, conditioning film formation on the surface, and tribological properties was discussed, which gives insights into designing Sp formulations with excellent detangling performance.

Quantifying the impact of braiding and combing on the integrity of natural African hair.

Afro hair breakage is most commonly attributed to grooming practices such as braiding, hair extensions and weaves, both for chemically treated hair and natural Afro hair. These grooming practices are also frequently associated with traction alopecia in clinical studies. However, there is little to no quantitative scientific data on the surface and internal hair fibre damage caused by grooming, including combing, on Afro hair. Qualitative and quantitative techniques such as scanning electron microscopy, cuticle cohesion and tensile testing were used to determine the effects of frequent braiding on the integrity of female Afro hair in 15 frequent braiders and 15 occasional braiders (control group) in Johannesburg, South Africa. Frequent braiders were women who braided more than 8 times per year, while occasional braiders typically limit braiding to only twice 2 per year. The severity of traction alopecia was quantified in both groups using the standard Marginal Traction Alopecia Scoring system. Surface damage on naturally curly Afro hair, that was combed but not braided, was assessed as another hairstyle option. All measurements showed a relationship between surface and internal hair fibre damage and braiding frequency. Frequent braiders had thinner hair, with more cuticle damage as shown by SEM and cuticle cohesion assessments. Their hair fibres were also significantly weaker (p<0.05), as shown by the tensile testing. In addition, they also had higher traction alopecia severity scores. In the combing impact assessment, a linear trend was observed between surface hair fibre damage and the number of combing strokes. Cuticle damage from 480 combing strokes was more severe than that from frequent braiding. Frequent braiding and combing damage natural Afro hair. Quantification of damage caused by different grooming practices identifies a need to develop products that could help mitigate specific hair damage associated with grooming practices. The degree of damage and subsequent hair loss could also be minimized by education on best braiding practices to protect the hair fibre and avoid hair follicle miniaturization caused by high traction hairstyles.

Study on properties of yak cashmere fiber

PurposeAs one natural fiber, yak cashmere has been used more and more widely on textile processing due to its excellent warmth retention property. Yarn spinning is the first and the most important step of textile processing. Yarn spinning is closely related to the fiber properties. That is, for giving the optimization spinning process of one new fiber, the properties of the new fiber should be studied firstly. Meanwhile, during the studying of the properties of the new fiber, comparative analysis method was usually used. That is, the property of the new fiber was common comparatively analyzed with other fibers. During the comparative analysis, the spinning process can be optimized. Therefore, in the paper, the properties of the yak cashmere were studied in detail and comparatively analyzed.Design/methodology/approachThe brown yak cashmere, cyan yak cashmere, white cashmere fiber, purple cashmere fiber, cyan cashmere fiber, camel hair fiber and mohair fiber, were chosen as the samples. The fiber length, fineness, strength, curls, moisture regain, mass specific resistance, surface morphology, infrared spectrum, melting behavior, thermal weight loss, friction, x-ray, were tested and comparatively analyzed.FindingsIt is shown that the compositions of yak cashmere and cashmere are similar, and makes the physical properties of yak cashmere and cashmere fiber similar. Comparing with the mohair, camel hair and cashmere fiber, the average length of yak cashmere is smaller and the dispersion of length distribution is larger, and the dispersion of yak cashmere strength is larger, which makes the yarn spinning of yak cashmere difficult, especially the high count pure yarn. However, comparing with the mohair, camel hair and cashmere fiber, the friction coefficient and friction effect of yak cashmere is larger, and yak cashmere fiber has relatively less curls and larger crimp rate and crimp recovery rate, and can improve the fiber spinnability.Originality/valueIn the paper, taking the brown yak cashmere, cyan yak cashmere, white cashmere fiber, purple cashmere fiber, cyan cashmere fiber, camel hair fiber, mohair fibers as the samples, the properties of the yak cashmere were studied in detail. The fiber length, fineness, strength, curls, moisture regain, mass specific resistance, surface morphology, infrared spectrum, melting behavior, thermal weight loss, friction, x-ray, were tested and comparatively analyzed. The studies can establish foundation for the optimization of the yak cashmere spinning process, and also can provide information for the end uses of the fiber.

The evolving mechanical response of curly hair fibres subject to fatigue testing

Cyclic testing of human hair reveals important details about the behaviour of fibres over many cycles of loading. Phenomena which are observed under static tensile tests give important clues about the form and behaviour of hair fibres, but these do not necessarily remain constant on the inevitable march to failure. In previous work, we demonstrated that curly fibres exhibited a toe-region during tensile tests. The form of curly fibres could be altered by mechanical manipulation but the curl could be recovered upon immersion in water. In this study, where straight and curly fibres are subject to cyclic loading, this characteristic toe-region was shown to be present in the first cycle of loading (for curly fibres). As the number of cycles increased (and the curly fibres progressively became straighter), the stress-strain response of curly fibres started to resemble that of straight fibres. This observation supports our previous hypothesis, which states that the toe-region can be attributed to the presence of a hydrogen bonding mechanism, which is present in curly fibres only, and can be altered by mechanical force. Interestingly, the alteration in load-bearing pattern in curly fibres did not necessarily translate to increased endurance, demonstrating that the relationship between fatigue and strength is a complex one in hair fibres.

Vivid biofluorescence discovered in the nocturnal Springhare (Pedetidae)

Biofluorescence has been detected in several nocturnal-crepuscular organisms from invertebrates to birds and mammals. Biofluorescence in mammals has been detected across the phylogeny, including the monotreme duck-billed platypus (Ornithorhyncus anatinus), marsupial opossums (Didelphidae), and New World placental flying squirrels (Gluacomys spp.). Here, we document vivid biofluorescence of springhare (Pedetidae) in both museum specimens and captive individuals—the first documented biofluorescence of an Old World placental mammal. We explore the variation in biofluorescence across our sample and characterize its physical and chemical properties. The striking visual patterning and intensity of color shift was unique relative to biofluorescence found in other mammals. We establish that biofluorescence in springhare likely originates within the cuticle of the hair fiber and emanates, at least partially, from several fluorescent porphyrins and potentially one unassigned molecule absent from our standard porphyrin mixture. This discovery further supports the hypothesis that biofluorescence may be ecologically important for nocturnal-crepuscular mammals and suggests that it may be more broadly distributed throughout Mammalia than previously thought.

Diatomite encapsulated AgNPs as novel hair dye cosmetics: Preparation, performance, and toxicity

Naturally-occurring diatomite has been successfully utilised as a unique encapsulating material to obtain a highly dispersed suspension of uniformly-sized silver nanoparticles (AgNPs). Plant derived gallic acid was used as the reducing and capping agent. High-resolution scanning and transmission electron microscopy results confirmed the attachment of AgNPs on the surface of diatom frustule and maintained an excellent dispersion stability against particle aggregation. The AgNPs obtained were employed for the colouration of bleached human hair owing to the local surface plasmonic absorption (LSPR) of the AgNPs. The effects of Ag/diatomite concentration, dyeing pH, temperature and time on the produced colour were investigated. Hair fibres treated under optimised conditions display good colour fastness toward solar radiation. The morphology and chemical composition of AgNP-dyed hair were determined by energy-dispersive spectroscopy, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy analyses. The biocompatibility of the Ag/diatomite composite, AgNPs, and the dyebaths were confirmed by in vitro acute dermal and ocular toxicity tests. The diatomite supporting AgNPs therefore hold good promise and enormous potential to be exploited for sustainable dyeing of human hair.

Characterization of Secondary Structure of Pig Hair Fiber Using Fourier-transform Infrared Spectroscopy

ABSTRACT Hair or bristle is one of the key by-products of humane slaughter of pigs. In the present study, Fourier-transform infrared (FTIR) spectroscopy was used for examining protein secondary structure of hair fiber from different breeds of pigs (Ghungroo, Ninag Megha, Hampshire, and Duroc). Prominent amide I (1635–1648 cm−1) and amide II (1517–1528 cm −1) bands could be observed in the spectra. Differences in presence/absence of certain FTIR bands between breeds suggests influence of genetic background in the structure of hair fiber. Deconvolution resolved secondary structure of protein in amide I region of spectra into corresponding α-helix (38.0 ± 2.9%), β-sheets (32.2 ± 2.0%), β-turns (19.4 ± 3.1%) and unorganized structural components (10.3 ± 2.5%). Heating of fibers from 80°C to 120°C resulted in changes in amide regions and α-helix to β-sheet ratio of amide I band. Further, correlations were calculated between area under the curve of various FTIR bands and tensile properties of the fiber. Area of FTIR band at 1635 cm −1 was positively correlated with tenacity, initial modulus, extensibility, and work of rupture (r = 0.30 to 0.39). In nutshell, the study reveals subtle differences in secondary structure of hair with respect to breed or temperature treatment and suggests relation between FTIR spectral characteristics and tensile properties.