Human Hair Fibers Research Articles

Effect of Freezing-Thawing on Clayey Soils Reinforced with Human Hair Fibers

ABSTRACTThe reinforcing of fine-grained soils using natural or synthetic fibers has been successfully applied today. The use of waste human hair fibers among natural fibers is seen as a sustainable solution as a reinforcing material. A series of free pressure tests were performed before and after the freezing-thawing cycle in order to examine the strength properties of the clayey soil (CS) reinforced with human hair fibers (HHF). Before freezing-thawing, clayey soil samples prepared with four different mass ratios of human hair fibers (0.5%, 1%, 1.5%, and 2% by dry weight) indicated 14–54% increases in strength, 7–49% increase were obtained after freezing-thawing. The highest strength increases before and after the freezing-thawing cycle has occurred in the mixture of CS+1.5% HHF. In addition, it was determined that the increase in pressure stress is remarkably increases with increasing human hair fiber ratio and cure time and freeze-thaw cycles. As a result, it is concluded that the CS reinforced with HHF can be utilized in cold climate zones.

Human pollution exposure correlates with accelerated ultrastructural degradation of hair fibers.

Exposure to pollution is a known risk factor for human health. While correlative studies between exposure to pollutants such as polycyclic aromatic hydrocarbons (PAHs) and human health exist, and while in vitro studies help to establish a causative connection, in vivo comparisons of exposed and nonexposed human tissue are scarce. Here, we use human hair as a model matrix to study the correlation of PAH pollution with microstructural changes over time. Two hundred four hair samples from 2 Chinese cities with distinct pollution exposure were collected, and chromatographic-mass spectrometry was used to quantify the PAH-exposure profiles of each individual sample. This allowed us to define a group of less contaminated hair samples as well as a more contaminated group. Using transmission electron microscopy (TEM) together with quantitative image analysis and blind scoring of 82 structural parameters, we find that the speed of naturally occurring hair-cortex degradation and cuticle delamination is increased in fibers with increased PAH concentrations. Treating nondamaged hair fibers with ultraviolet (UV) irradiation leads to a more pronounced cortical damage especially around melanosomes of samples with higher PAH concentrations. Our study shows the detrimental effect of physiological concentrations of PAH together with UV irradiation on the hair microstructure but likely can be applied to other human tissues.

Automated Measurement of Spatially Resolved Hair-Hair Single Fiber Adhesion.

The adhesion force between individual human hair fibers in a crosshair geometry was measured by observing their natural bending and adhesive jumps out of contact, using optical video microscopy. The hair fibers' natural elastic responses, calibrated by measuring their natural resonant frequencies, were used to measure the forces. Using a custom-designed, automated apparatus to measure thousands of individual hair-hair contacts along millimeter length scales of hair, it was found that a broad, yet characteristic, spatially variant distribution in adhesion force is measured on the 1 to 1000 nN scale for both clean and conditioner-treated hair fibers. Comparison between the measured adhesion forces and adhesion forces modeled from the hairs' surface topography (measured using confocal laser profilometry) shows they have a good order-of-magnitude agreement and have similar breadth and shape. The agreement between the measurements and the model suggests, perhaps unsurprisingly, that hair-hair adhesion is governed, to a first approximation, by the unique surface structure of the hairs' cuticles and, therefore, the large distribution in local mean curvature at the various individual contact points along the hairs' lengths. We posit that haircare products could best control the surface properties (or at least the adhesive properties) between hairs by directly modifying the hair surface microstructure.

Experimental investigation of soil reinforced with human hair fibre and chloride compounds

Many researches and advancements were carried to increase the strength of soil. Expansive soil contains montmorillonite clay mineral which is high swelling in nature. It is highly sensitive to moisture variation and it leads to encounter many engineering problems like low bearing capacity and settlement. Fibre reinforced soil is one among those advancements which offers a convenient, practical and economical method for overcoming sudden settlement and low bearing capacity. The soil can be reinforced with human hair because of its tensile property. Human Hair Fibre (HHF) is a waste material available at low cost and is not degradable in nature. Present study focuses on determining the strength characteristic of soil sample treated with human hair fibre and chloride compounds in different curing periods. Chemicals were added to the sample in varying percentage related to dry weight of the soil sample. Addition of human hair fibre and chloride compounds enhances the engineering properties of clayey soil. Chloride compounds were added at different percentages (2%, 4%, 6%, 8%, and 10%) to the soil and changes in the engineering property of soil such as penetration resistance, compaction characteristics and unconfined compressive strength of the soil were investigated. Based on present experimental study, the increase in the percentage of chloride compounds increases the dry density of the soil up to an optimum value then it decreases. The results showed that addition of HHF and chloride compounds stabilize the clayey soil to a particular extent.

Conformation changes in human hair keratin observed using confocal Raman spectroscopy after active ingredient application.

ObjectiveIn hair care cosmetic products’ evaluation, one commonly used method is to evaluate the hair appearance as a gold standard in order to determine the effect of an active ingredient on the final state of the hair via visual appreciation. Although other techniques have been proposed for a direct analysis of the hair fibres, they give only surface or structural information, without any accurate molecular information. A different approach based on confocal Raman spectroscopy has been proposed for tracking in situ the molecular change in the keratin directly in the human hair fibres. It presents a high molecular specificity to detect chemical interactions between molecules and can provide molecular information at various depths at the cortex and cuticle levels.MethodsTo evaluate the potential of confocal Raman spectroscopy in testing the efficiency of cosmetic ingredients on keratin structure, we undertook a pilot study on the effectiveness of a smoothing shampoo on natural human hair, by analysing α‐helix and β‐sheet spectral markers in the Amide I band and spectral markers specific to the cystin sulfur content.ResultsWe confirmed that an active proved to be effective on a gold standard decreases α‐helix keratin conformation and promotes β‐sheet keratin conformation in the hair fibres. We also showed that treatment with the effective active decreases the intensity of covalent disulfide (S–S at 510 cm‐1) cross‐linking bands of cysteine. These data confirm that the effective active also acts on the tertiary structure of keratin.ConclusionFrom these experiments, we concluded that the effective active has a smoothing effect on the human hair fibres by acting on α‐helix and β‐sheet keratin conformation and on the tertiary structure of keratin. Based on these results, confocal Raman spectroscopy can be considered a powerful technique for investigating the influence of hair cosmetic ingredients on keratin structure in human hair fibres. Moreover, this analytical technique has the advantage of being non‐destructive and label free; in addition, it does not require sample extraction or purification and it can be applied routinely in cosmetic laboratories.

An Experimental Investigation on Hair Fibre as Fibre Reinforcement in Concrete

Fibre Reinforced Concrete (FRC) can give us the ample, practical as well as parsimonious technique for defeating cracking in the concrete and comparable kind of inadequacies. The concrete is frail in tension so a few stages must be taken to be received to conquer this insufficiency. The strength of Human Hair fibre is more in tension consequently may be utilized very finely as a fibrous stuff in concrete to furnish it with the rigidity which it needs. Hair Fibre (HF) a substitute non-biodegradable material is accessible in plenitude and at an exceptionally modest expense. It likewise makes ecological issues for its decay, present examination has been embraced to ponder its impact on plain cement concrete taking the following into account;flexural strength, crushing strength, compressive strength and micro-cracking control for making the cement concrete more financial and also to lessen natural issues.

Raman spectroscopy and electronic microscopy structural studies of Caucasian and Afro human hair

Human hair fibre is subjected to various structural modifications due to the application of chemicals such as dyes, shampoos and bleaches and/or physical procedures such as heating, and often more than one procedure is performed on the same hair. The present work aims to analyze the changes incurred in hair samples of two ethnic groups, namely Caucasian and Afro, before and after different treatments such as thermal, bleaching and straightening. In addition to observing the damage caused by each treatment separately, the study of samples that received all three treatments was carried out. For molecular structural characterization, the Raman vibrational spectroscopic technique was used and scanning electron microscopy (SEM) was used for morphological analysis of the hair fibres. This investigation has shown, through vibrational spectroscopy, that several important bonds have been modified, such as the S-S, C-S, C-C and S-O bonds as well as the secondary structures of proteins that have indergone changes in their conformation as a result of the treatment. Hair from the two ethnic groups showed small differences in relation to each applied treatment. Excessive heat generated a higher rate of Raman spectral band intensity changes when compared to the other treatments and it was observed that the action of several treatments on the same hair fibres resulted in even more pronounced structural changes. Finally, scanning electron microscopy showed that each treatment caused a different morphological deformation pattern on the capillary surface of the human hair.

Effects of cosmetic treatments on the morphology, biotribology and sensorial properties of a single human hair fiber

Human hair has a complex multi-scale structure that is extremely sensitive to several external factors. Hair fiber has three compartments: cuticle (scales), cortex and medulla.In the everyday life, hair experience important mechanical and chemical solicitations, such as smoothing, combing, drying and even washing, which can induce cracks in the cuticle. These damages diminish the mechanical properties of the cortex and contribute to a decrease in the brightness and softness of the hair.In the present article, the effects of different cosmetic treatments: bleaching, coloring and smoothing (with different temperatures) have been explored. Firstly, the morphology of hair was measured by interferometry. A multi-scale roughness characterization was performed by applying continuous wavelet transform. This method quantified the arithmetic mean of the surface topography at each wave length and permitted observing the evolution of the cuticle morphology before and after treatment. Secondly, a patented haptic tribometer system was used to measure the friction coefficient and acoustic vibrations generated during the tribological test. Previous results have shown that vibrations are related to the softness of the hair surface.The results show that all the treatments change the morphology and biotribology of hair by damaging the hair cuticle. These changes impact the sensorial properties of hair. In particular, the morphology of colored and bleached hair, compared to virgin one, is strongly modified: the scales are less defined, and the roughness is increased. These morphological modifications are correlated with an increase of the friction coefficient of around 50%, and acoustic vibratory level of around 2%, indicated a decrease of the sensorial properties. The hair fiber becomes rougher, dull and less soft. On the contrary, thermomechanical treatments of previously damaged hair, impact the morphology and biotribology of hair differently. The cuticle scales are flattened and the values of the friction coefficient and acoustic vibratory level decrease to reach the virgin hair values. Thus, the hair fiber seems to be smoother, brighter and softer.In conclusion, these results are essential for understanding the impact of different solicitations on the physical and sensorial properties of hair.

Stiffness of Human Hair Correlates with the Fractions of Cortical Cell Types

(1) Background: The objective of this work was to elucidate the hair microstructure which correlates with the stiffness of human hair fibers. (2) Methods: Bending moduli of hair fibers were evaluated for the hair samples from 156 Japanese female subjects. Hair transverse sections were dual-stained with fluorescent dyes which can stain para- and ortho-like cortical cells separately, and observed under a fluorescence light microscope. Atomic force microscopy nanoindentation measurements were performed to examine the modulus inside macrofibrils. (3) Results: The difference in bending moduli between the maximum and the minimum values was more than double. The hair of high bending modulus was rich in para-like cortical cells and the bending modulus significantly correlated with the fraction of para-like cortical cells to the whole cortex. On the other hand, the elastic moduli inside macrofibrils were almost same for the para- and ortho-like cortical cells. (4) Conclusions: Hair bending modulus depends on the fractions of the constitutional cortical cell types. The contribution of the intermacrofibrillar materials, which differed in their morphologies and amounts of para- and ortho-like cortical cells, is plausible as a cause of the difference in the modulus of the cortical cell types.

Systems Approach to Human Hair Fibers: Interdependence Between Physical, Mechanical, Biochemical and Geometric Properties of Natural Healthy Hair.

Contextual interpretation of hair fiber data is often blind to the effects of the dynamic complexity between different fiber properties. This intrinsic complexity requires systems thinking to decipher hair fiber accurately. Hair research, studied by various disciplines, follows a reductionist research approach, where elements of interest are studied from a local context with a certain amount of detachment from other elements or contexts. Following a systems approach, the authors are currently developing a cross-disciplinary taxonomy to provide a holistic view of fiber constituents and their interactions within large-scale dynamics. Based on the development process, this paper presents a review that explores the associated features, interrelationships and interactive complexities between physical, mechanical, biochemical and geometric features of natural, healthy hair fibers. Through the review, the importance of an appropriate taxonomy for interpreting hair fiber data across different disciplines is revealed. The review also demonstrates how seemingly unrelated fiber constituents are indeed interdependent and that these interdependencies may affect the behavior of the fiber. Finally, the review highlights how a non-integrative approach may have a negative impact on the reliability of hair data interpretation.

Effect of Waste Human Hair Fibers on Shear Behavior of Sand in Dry and Saturated Conditions

Abstract Soil reinforcement using natural fibers has been successfully employed in different projects. Among the natural fibers, the use of waste human hair fibers as a reinforcing material can be the solution for sustainable development. This study presents characterization of human hair fiber–reinforced sand using direct shear tests under dry and saturated conditions. Tests were conducted in three series: (i) Test Series-1: using unsorted human hair fibers (as collected from barber shops) under dry conditions, (ii) Test Series-2: using unsorted human hair fibers under saturated conditions, and (iii) Test Series-3: sorted fibers with lengths of 10, 15, and 20 mm to examine the effect of fiber length when under saturated conditions of sand. All test specimens were prepared at 80 % relative density. Initially, experiments were carried out on dry sand with fiber reinforcement up to 2.0 % by weight of sand. Under saturated conditions, the percentage of fiber content was restricted up to 1.0 %, as formation of fiber clusters was noticed beyond 1.0 %. Under saturated conditions, specimens were prepared with initial moisture content ranging from 1.0–3.0 % by weight of soil for easy homogeneous mixing and then saturated. It is found that the reinforcement using human hair fibers significantly affects the shear behavior of dry sand. However, under saturated conditions, the human hair fiber reinforcement is able to sustain shear strength parameters similar to unreinforced sand, even though these parameters are likely to reduce. The use of unsorted fibers as reinforcement is more beneficial than that the use of the sorted fibers of uniform length.

Experimental Studies on Behavior of Keratin Based Human Hair Fiber - A New Reinforcing Material for Composites

Composite materials are formed by two or more constituents at macroscopic level. Type and form of fiber plays a vital role in imparting required properties to the composite. Many researchers contributed to the development of artificial fiber composites which are not environmental friendly in nature. Sizable research is also done in the area of natural fiber composites. Human hair is a non-biodegradable waste available in abundant quantity across the world, but is rarely explored for applications in engineering fields. In the present study, a review on behavior of human hair fibers was made to understand their suitability as a reinforcing material in composites. Morphology of the hair fibers is reviewed and the density of the hair fibers was determined using Archimedes principle. Tensile strength of the hair fibers is experimentally estimated. Chemical resistivity and burning tests were conducted. Tensile and flexural properties of hair fiber reinforced polyester composite were experimentally determined and compared.

Fabrication and characterization of chitosan coated human hair reinforced phytagel modified soy protein-based green composite

AbstractIn the present investigation, human hair reinforced soy protein isolate (SPI)-based green composites modified with 40 wt.% phytagel and 12.5 wt.% glycerol were developed. Characterization of the prepared composites was done through water absorption, tensile test, scanning electron microscopy (SEM) and dynamic mechanical analysis (DMA). Composites having 2 wt.% of human hair fiber gave the optimum results for the tensile test. At 2 wt.% of human hair composition maximum tensile strength 17.23 MPa was obtained whereas the tensile strength of neat SPI was 8.54 MPa. SEM images show the interfacial bonding between human hair fiber and SPI resin and gave the clear explanation of the change in tensile strength and water absorption %. Chitosan coating was applied to fabricated composites to reduce water uptake. Chitosan coated sample showed considerable improvement in tensile strength, water uptake and glass transition temperature.

An Experimental Study on Human Hair Fiber Reinforced Concrete

This paper present the fresh and harden property of human hair fiber reinforce concrete. From the ancient time many researcher’s and investors carried out research to enhance the physical and mechanical property of concrete. Now a day’s human hair is considered as a waste material and an alternative non degradable matter available in abundance at cheap coast. Present study have been under taken to study the effect of human hair on medium grade concrete on basis of comprehensive strength, effect of crack control and reduce environmental problem. Further Rise Husk Ash (RHA) is a Pozzolonic material used as cement replacement in concrete. Experiments were conducted on concrete on standard cube size with addition of various 0, 0.75, 1.5 and 2.25 % of human hair fiber i.e. by weight of cement and RHA with 0, 5,10 15 and 20% partial replacement of cement. This investigation demonstrated significant improvement in the properties of concrete by the addition of human hair as fiber reinforcement concrete.

Effect of surface treatment on hair fiber as reinforcement of HDPE composites: Mechanical properties and water absorption kinetics

The objective of this work was to investigate the effect of surface improvement on human hair fiber (HF) based high-density polyethylene (HDPE) reinforced polymer composites. A universal testing machine was used for the characterization of the mechanical behaviors of different types of HF base reinforced HDPE composites, and studies were conducted for the optimization of male/female fiber percentage (15% HF) in polymer composites. The alkali treatment (AT) and acrylic acid treatment (AAT) of HF reinforced HDPE composites showed a remarkable improvement in tensile strength (upto 15.487MPa and 15.638MPa, respectively), which was significantly changed in comparison to the tensile strength of untreated composites. FTIR and SEM test were used to characterize the fiber surface and HF/HDPE reinforced composites. Water absorption kinetics was investigated for the study of diffusion mechanism and kinetics of composites materials, which would be useful to boost the applications of the composite in different areas.

Effects of Differing Purification Methods on Properties of Keratose Biomaterials.

Keratin is a natural polymer found in hair fibers, skin, and nails. It has been investigated as a biomaterial since the 1970s, and has more recently been shown to have applications in healthcare such as medical devices and tissue engineering. Keratins are one of few intermediate filament forming proteins and demonstrate a propensity to self-assemble. Keratins extracted and purified from natural sources such as human hair fibers and wool tend to have weak mechanical properties, but can be cross-linked to form more robust structures. When extracting and purifying keratin proteins from natural fibers, the method of extraction is paramount to obtaining materials that retain the ability to self-assemble and form network structures with appreciable mechanical strength. Here, we compare and contrast two methods for purifying keratin extracts-one in which conventional purification methods are used and a second in which solution aggregation is minimized to promote purification of the molecular entities with the highest propensity for self-assembly, dimers of type I and type II hard keratins. Material that underwent the latter, novel extraction method exhibited higher purity in the form of a lower peptide content. Moreover, hydrogels formed from this material were found to demonstrate greater resistance to shear, and interestingly, increased susceptibility to enzymatic degradation in comparison to hydrogels formed from conventionally extracted material. This novel keratin purification method allows for enrichment of compounds with increased self-assembly behavior, and has the potential to overcome limitations noted in other studies where biomaterials fabricated from purified keratins demonstrated inferior mechanical characteristics.

Effectiveness of hair and wave polypropylene fibers for concrete roads

Human hair fibers are abundantly available as waste and wave polypropylene fibers are commercially available. These fibers are studied with limited scope from only material point of view. In this study, the mechanical properties of hair fiber reinforced concrete (HFRC) and wave polypropylene fiber reinforced concrete (WPFRC) are explored for its possible applications in concrete roads. The properties are experimentally evaluated as per ASTM standards and the effectiveness of fibers in concrete are checked by comparing with that of control mix. In addition, by using the relevant properties, concrete road design is also compared. It is found that the compressive, flexural and splitting-tensile strengths of HFRC are improved by 12.4%, 16.2% and 19.1%, respectively, and that of WPFRC are increased by 11.7%, 21.5% and 17.5%, respectively. With these improvements, the thickness of concrete road for a particular studied loading condition can be reduced by 12.5 mm. This can result in cost saving (per lane per km) of 3% and 1.7% by use of HFRC and WPFRC, respectively. The performance of concrete road is also expected to be better because of improved toughness of HFRC and WPFRC.

Water mediated dielectric polarizability and electron charge transport properties of high resistance natural fibers

Recent studies showed that silk and human hair fibers develop thermoelectric properties at optimal water, temperature and light conditions. The nature of charge carriers and the role of water in mediating charge conduction in these fibers is an unexplored issue. By studying four different classes of natural fibers, viz., silk cocoon, human hair, jute and corn silk, we uncover their common electrical transport properties and its dependence on water concentration and temperature. All these fibers uniformly exhibit nonlinear, hysteretic current - voltage characteristics, which scale with water concentration. The optimal electrical conductivity shows thermally activated hopping transport mechanism. Scanning tunneling microscope (STM) and dielectric measurements of silk cocoon fibers showed the electronic density of states and dielectric properties of the hydrated medium enhances with water concentration. Electron paramagnetic resonance (EPR) study reveals that the charge carriers in these membranes are electronic in nature. Our results are explained through the mechanism of hopping of a Polaron, which is an electron surrounded by positive charge fluctuations created by water molecules. The mechanism unravels the peculiar role water plays in mediating electrical activity in these membranes and also opens the possibility for exploring such charge transport mechanism in other biological membranes.

Processing and Mechanical Behaviour of Human Hair Fiber Reinforced Polymer Composites

Processing and Mechanical Behaviour of Human Hair Fiber Reinforced Polymer Composites

Wear characteristics of epoxy based hybrid composites reinforced with short hair fibers and glass micro spheres

This paper reports on the sliding wear behavior of a class of hybrid composites consisting of epoxy, short human hair fibers and glass micro-spheres. Human hair is a biological waste which creates many environmental problems due to its low rate of degradation. But it also has many unique properties like low thermal conductivity, higher strength in tension, unique chemical composition, higher elasticity, scaly surface etc. Although a number of ways are in place for the utilization of waste human hair such as in fertilizers and pesticides, in cosmetic industries, artwork, fabrics, stuffing toys, household items etc., its use in polymers as a reinforcing element has not been researched properly. In view of this, the present work makes an attempt to fabricate a class of hybrid polymer composites reinforced with short human hair fibers (SHF) and solid glass micro-spheres (SGM). SGM (10wt.%) filled epoxy matrix composites are prepared with four distinct fiber loading (0, 2, 4, 6 wt.%). Mechanical properties such as tensile, compressive and flexural strengths are evaluated by conducting tests as per appropriate ASTM standards. Using a friction and wear test rig of pin-on-disc type sliding wear tests are performed on these composites as per ASTM G99. Four process parameters and each at four levels are considered for the experimentation. In order to identify the significant control factors influencing the wear rates of these composites a design of experiment approach based on Taguchi’s orthogonal array is adopted. Effects of SGM and hair fiber reinforcement on the mechanical and wear characteristics of epoxy have been studied. The test results are compared with those obtained for composites with only SHF reinforcement under similar test conditions. It is found that while reinforcement of short hair fiber enhances the wear performance of epoxy, addition of SGM further improves it. Armed with a fairly good wear resistance, these composites can possibly have potential applications such as in brake shoes, brake pads etc.