Figure - available via license: Creative Commons Attribution-NonCommercial 3.0 Unported
Content may be subject to copyright.
Hair surface damage measured by scanning electron microscopy after the hair drying process. The extent of damage to hair surfaces increased as the temperature rose. Treatments: (A) no treatment, (B) shampooing and drying without using a hair dryer (room temperature, 20℃), (C) shampooing and drying with a hair dryer for 60 seconds at a distance of 15 cm (47℃), (D) shampooing and drying with a hair dryer for 30 seconds at a distance of 10 cm (61℃), (E) shampooing and drying with a hair dryer for 15 seconds at a distance of 5 cm (95℃).
Source publication
Hair dryers are commonly used and can cause hair damage such as roughness, dryness and loss of hair color. It is important to understand the best way to dry hair without causing damage.
The study assessed changes in the ultra-structure, morphology, moisture content, and color of hair after repeated shampooing and drying with a hair dryer at a range...
Similar publications
Ti-andradites were synthesized at a pressure of P(H2O)=3 kbar and temperatures of 700–800° C. Oxygen fugacities were controlled by solid state buffers (Ni/NiO; SiO2 + Fe/Fe2SiO4). The Fe2+-and Fe3+-distribution was determined by low temperature Mössbauer spectroscopy. The water content was measured by a solid's moisture
analyzer. The chemical compo...
The leaves of Kaffir lime (Citrus hystrix DC) are marketed in dried or powdered form. In this research, the effect of oven drying at a relatively low temperature but in a long time with or without the following pulverization on the characteristics of kaffir lime leaves was investigated. The change of moisture analyzed by vacuum oven method, the col...
Adsorption chillers are characterized by low electricity consumption, lack of moving parts, and high reliability. The disadvantage of these chillers is their large weight due to low adsorbent sorption capacity. Therefore, the attention is turned to finding a sorbent with a high water sorption capacity and enhanced thermal conductivity to increase c...
Many methods exist for estimating the moisture of dead fine fuels but the same does not happen for live fuels, since their water content is largely controlled by internal physiological mechanisms within the plant and therefore more difficult to assess. The commonly accepted reference method for measuring fuel moisture content is oven drying, which...
Citations
... Many workers have observed and described damaged and fractured hair using scanning electron microscopy. Early signs of damage include small surface cracks which are usually oriented longitudinally (figure 3a) [23] and lifting of cuticle tiles (figure 3b) [24]. Cuticle has a much lower strain to failure than cortex and so will tend to separate from the cortex during tensile loading, long before the cortex itself fails. ...
... Much has been written about the effects of everyday actions (e.g. brushing, drying [24] and sunlight [26]) and cosmetic treatments (e.g. bleaching [26], curling [27] and dying [28]) as well as the effects of products intended to reduce or repair damage [29]. ...
... Examples of cuticle surface damage. (a) Longitudinal cracking[23]; (b) lifting of cuticle tiles[24]. ...
Splitting of hair, creating ‘split ends’, is a very common problem which has been extensively documented. However, the mechanics underlying the splitting phenomenon are poorly understood. This is partly owing to the lack of a test in which splitting can be generated and quantified under laboratory conditions. We developed three new tests, known as ‘loop tensile’, ‘moving loop’ and ‘moving loop fatigue’, aiming to simulate the mechanical environment of tangles of hair strands during combing. We tested straight strands of human hair, comparing low-quality hair (from a subject who experienced split ends) with hair from a control (non-splitting) subject. Significant differences were found, especially in the moving loop fatigue test where the low-quality hair failed in fewer cycles. Splitting occurred in both types of hair, but with the crucial difference that in the low-quality hair, splits originated inside the hair strand and propagated longitudinally over considerable distances, while in the control hair, splits originated at the strand surface and remained short. Bleaching of the control hair changed its behaviour, making it similar to that of the low-quality hair. Some simple calculations emphasized the role of longitudinal shear stress and shear stress intensity in generating microcracks which could then propagate within the moving loop, paving the way for a future theoretical model of the splitting mechanism.
... However, maintaining hair luster can be challenging, as it is frequently compromised by a variety of stressors. These include exposure to ultraviolet (UV) radiation, physical and chemical damage, and nutritional deficiencies, all of which can degrade the hair shaft and cuticles, diminishing the hair's natural shine and smoothness [2,3]. ...
Hair luster is a key attribute of healthy hair and a crucial aspect of cosmetic appeal, reflecting the overall health and vitality of hair. Despite its significance, the advancement of therapeutic strategies for hair luster enhancement have been limited due to the absence of an effective experimental model. This study aimed to establish a novel animal model to assess hair gloss, employing ultraviolet (UV) irradiation on C57BL/6 mice. Specifically, UVB irradiation was meticulously applied to the shaved skin of these mice, simulating conditions that typically lead to hair luster loss in humans. The regrowth and characteristics of the hair were evaluated using a dual approach: an Investigator’s Global Assessment (IGA) scale for subjective assessment and an image-based pixel-count method for objective quantification. These methods provided a comprehensive understanding of the changes in hair quality post-irradiation. To explore the potential reversibility of hair luster changes, oral minoxidil was administered, a treatment known for its effects on hair growth and texture. Further, to gain insights into the underlying biological mechanisms, bulk RNA transcriptomic analysis of skin tissue was conducted. This analysis revealed significant alterations in the expression of keratin-associated protein (KRTAP) genes, suggesting modifications in hair keratin crosslinking due to UV exposure. These changes are crucial in understanding the molecular dynamics affecting hair luster. The development of this new mouse model is a significant advancement in hair care research. It not only facilitates the evaluation of hair luster in a controlled setting but also opens avenues for the research and development of innovative therapeutic strategies. This model holds promise for the formulation of more effective hair care products and treatments, potentially revolutionizing the approach towards managing and enhancing hair luster.
... 2. Dry hair : Shampooing too often causes dry hair. Although squeaky clean hair may be a good thing, many overdo it by washing once, sometimes twice or per day which will strip away all of the hair's natural oils [8]. 3. Oily hair : Oily hair occurs when the scalp produces an excess amount of natural oil called sebum which is produced by Sebaceous glands, it may sometimes produce overload, leading to excess amounts of oil. ...
Hair plays a vital role in optimizing the personality of an individual as the hair is the primary noticeable part of external body and beauty for Women as well as men. The hair and scalp nature have important psychological impact on human societies. Even small changes in hairs like hair fall, whitening or greying of hair affect the self-confidence and self-esteem of an individual. For preventing and fighting against the hair problems, herbal hair scrub serves as an effective remedy. The goal of present review article is to highlights efficacy of herbal drugs on hair loss and also outlined that prevention and treatment can easily done by formulating hair scrub from those herbal drugs
... Although they are very efficient for the desired effect, these procedures also cause cumulative damage to the hair fiber, with weakening, dehydration, pH reduction and loss of the natural elasticity of the hair (JOHNSON, 1997;LIMA et al., 2019). The heating process removes the free and strongly bound water from the hair fiber, which can lead to vaporization, carbonization and even decomposition of the hair shaft, with thermal denaturation of the keratin, breaking chemical bonds and unfolding the α-helix structure (LEE et al., 2011;LIMA et al., 2019). ...
Thermal procedures aiming hair dressing, such as hair brushes, hair dryers or hair straighteners, usually involve higher temperatures, which progressively damages the hair fiber structure. The search for heat protectants for reducing this thermal damage has been growing, especially containing green components from vegetable source. To be efficient, the heat protectants should adequately spread throughout the entire hair shaft, covering the entire surface to be protected. Thus, the influence of the lipids in the in vitro spreadability of heat protectants was determined in this study. This influence was determined in a central composite rotational design 23, and spreadability was the dependent variable. Cetostearyl alcohol, shea butter and coconut oil concentration ranged between 0.64 and 7.36% (w/w) and the emulsions were prepared by hot homogenization with mechanical stirring. In vitro spreadability was determined by using an apparatus containing a square glass plate positioned on a circular plate with a 1 cm diameter hole in the center, on which a fixed amount of sample was applied to be pressed onto the surface by a fixed weight (5 g). Changes in the concentration of the components directly influenced the product spreadability (p < 0.05), which was higher around the central point for shea butter and coconut oil concentrations (4%) and at low concentrations of cetostearyl alcohol (0.64%). The studied components directly influenced the spreadability of the final product, which can be optimized in a rational pathway to obtain an adequate coverage throughout the hair shaft and desired thermal protection. Keywords: Cosmetics. Factorial design. Hair coverage. Hair damage. Thermoprotective. ResumoProcedimentos térmicos para pentear os cabelos, como escovas, secadores ou chapinhas, geralmente envolvem temperaturas elevadas, o que danifica progressivamente a estrutura da fibra capilar. A busca por protetores térmicos para redução deste dano térmico vem crescendo, principalmente contendo componentes verdes de origem vegetal. Para serem eficientes, os protetores térmicos devem se espalhar adequadamente por toda a haste capilar, cobrindo toda a superfície a ser protegida. Assim, a influência dos lipídios na espalhabilidade in vitro de protetores térmicos foi determinada neste estudo. Essa influência foi determinada em um delineamento composto central rotacional 23 e a espalhabilidade foi a variável dependente. As concentrações de álcool cetoestearílico, manteiga de karité e óleo de coco variaram entre 0,64 e 7,36% (p/p) e as emulsões foram preparadas por homogeneização a quente com agitação mecânica. A espalhabilidade in vitro foi determinada por meio de um aparato contendo uma placa de vidro quadrada posicionada sobre uma placa circular com um orifício central de 1 cm de diâmetro, na qual foi aplicada uma quantidade fixa de amostra para ser pressionada na superfície por um peso fixo (5 g). A variação na concentração dos componentes influenciou diretamente na espalhabilidade do produto (p < 0,05), sendo maior em torno do ponto central para as concentrações de manteiga de karité e óleo de coco (4%) e em baixas concentrações de álcool cetoestearílico (0,64%). Os componentes estudados influenciaram diretamente na espalhabilidade do produto final, que pode ser otimizado de forma racional para se obter uma cobertura adequada em toda a haste capilar e a proteção térmica desejada. Palavras-chave: Cosméticos. Planejamento Fatorial. Cobertura CAPILAR. Danos Capilares. Termoprotetor
... Moreover, regular dying and/or bleaching of hair causes unfavorable growth patterns, reduced glossiness, and difficulty in management; thus, affecting the visual perception of the hair, which could further impact a person's confidence level [2,3]. Additionally, habitual usage of a hair drier can cause roughness, dryness, and color loss due to a rapid decrease in hair moisture after exposure to warm air [4]. Natural phenomena often lead to changes in hair structure and color. ...
... Thus, the antistatic function of shampoos is crucial for reducing these effects by dissipating excess electrostatic charges on the hair [27]. The antistatic effect of the PPC shampoos was evaluated by applying each shampoo containing different PPC samples (1)(2)(3)(4) to dry hair samples and placing the treated hair close to a rubbed balloon. A shampoo without additional PPC was used as a control. ...
In this study, we developed a hair-coating polyphenol complex (PPC) that showed ultraviolet (UV) protection properties, antistatic features, and the capability to enhance the mechanical strength of damaged hair. PPCs prepared with different ratios of tannic acid (TA), gallic acid (GA), and caffeic acid (CA) simultaneously increased the self-recovery of damaged hair by protecting the cuticle. PPC prevented light from passing through the damaged hair during exposure to UV radiation. Moreover, surfaces coated with PPC1 (TA:GA:CA, 100:20:0.5) exhibited a higher conductivity than surfaces coated with PPCs with other ratios of TA, GA, and CA, with a resistance of 0.72 MΩ. This influenced the antistatic performance of the surface, which exhibited no electrical attraction after being subjected to an electrostatic force. Additionally, damaged hair exhibited a significant increase in durability and elasticity after coating with a PPC1-containing shampoo, with a tensile strain of up to 2.06× post-treatment, indicating the recovery of the damaged cuticle by the PPC complex. Furthermore, PPC1-containing shampoo prevented damage by scavenging excess reactive oxygen species in the hair. The combination effect promoted by the natural PPC offers new insights into hair treatment and paves the way for further exploration of hair restoration technology.
... However, its regular use causes damage to the hair shaft. While air-dried hair shows a well-protected surface, blowdried hair shows a higher degree of damage [30]. The hair surface becomes more damaged as the temperature increases [30]. ...
... While air-dried hair shows a well-protected surface, blowdried hair shows a higher degree of damage [30]. The hair surface becomes more damaged as the temperature increases [30]. Blow-drying the hair causes the scale edges to become concaveshaped due to cuticle layer splitting [31]. ...
... Hair color is also affected by heat, becoming lighter after repeated shampooing and drying. These changes in color are visible after just 10 blow-drying processes at 95 °C [30]. ...
Hair is constantly exposed to various adverse external stimuli, such as mechanical or thermal factors, that may cause damage or cause it to lose its shine and smooth appearance. These undesirable effects can be minimized by using hair conditioners, which repair the hair and restore the smooth effect desired by the consumer. Some of the currently used conditioning agents present low biodegradability and high toxicity to aquatic organisms. Consumers are also becoming more aware of environmental issues and shifting their preferences toward natural-based products. Therefore, developing novel, sustainable, natural-based derivatives that can act as conditioning agents in hair care products and thus compete with the traditional systems obtained from non-renewable sources is highly appealing. This paper presents the key physicochemical aspects of the hair conditioning process, including hair structure and degradation, and reviews some of the new alternative conditioning agents obtained from natural resources.
... Even if only heat of 40-70 o C is applied to the hair, the epidermis layer falls off and the cortex is exposed [24]. Heat treatment is essential for dyeing and perming, and it is common that hair protein loss increases proportionally as the temperature rises during dyeing and perming [25]. There was no significant difference in protein leakage between the negative control and the positive control groups. ...
... It is to be noted that in the absence of the avalanche gain the final temperature would reach only about 100°C where no significant damage to the cortex has been observed. 33 A less pronounced decrease in transmittance was observed following the irradiation by 50 consecutively delivered low fluence (F p = 5 J/cm 2 ) pulses. The corresponding final elevated temperature of about 90°C (see Figure 4B) is in the range for which only damage to the cuticle, without damage to the cortex is expected. ...
... The corresponding final elevated temperature of about 90°C (see Figure 4B) is in the range for which only damage to the cuticle, without damage to the cortex is expected. 33 Accordingly, Figure 9B shows a slightly deteriorated hair cuticle exhibiting irregular surface geometry. ...
... Similarly, transmission electron microscopy showed progressively increased number of longitudinal cracks in the cuticle when the hair was exposed to temperatures of 47°C, 61°C, or 95°C. 33 In terms of cortex damage, there have been no signs of damage reported at any of temperatures below 100°C. 33 On the other hand, a total evaporation of the bound water followed by a total degradation of the hair shaft has been observed around 200°C. ...
Background and objectives:
In this study, we investigate the photothermal response of human hair using a pulsed laser source employed in the hair removal treatment. The purpose is to understand the dynamics behind the most common clinical practice to better define the salient features that may contribute to the efficiency of the process.
Study design/materials and methods:
Temperature changes of hair samples (dark brown color) from a human scalp (skin type Fitpatrick II) were measured by a thermal camera following irradiation with single and multiple neodymium: yttrium-aluminum-garnet (Nd:YAG) (1064 nm) and alexandrite (755 nm) laser pulses. Particularly, the hair was treated with an individual laser pulse of a sufficiently high fluence, or with a series of lower fluence laser pulses. We investigated the temperature increase in a broad range of fluence and number of pulses. From the data analysis we extrapolated important parameters such as thermal gain and threshold fluence that can be used for determining optimal parameters for the hair removal procedure. Our experimental investigations and hypothesis were supported by a numerical simulation of the light-matter interaction in a skin-hair model, and by optical transmittance measurements of the irradiated hair.
Results:
An enhancement of the temperature response of the irradiated hair, that deviates from the linear behavior, is observed when hair is subjected to an individual laser pulse of a sufficiently high fluence or to a series of lower fluence laser pulses. Here, we defined the nonlinear and rapid temperature built-up as an avalanche effect. We estimated the threshold fluence at which this process takes place to be at 10 and 2.5 J/cm2 for 1064 and 755 nm laser wavelengths, respectively. The thermal gain expressed by the degree of the deviation from the linear behavior can be higher than 2 when low laser fluence and multiple laser pulses are applied (n = 50). The comparison of the calculated gain for the two different laser wavelengths and the number of pulses reveals a much higher efficiency when low fluence and multiple pulses are delivered. The avalanche effect manifests when the hair temperature exceeds 45°C. The enhanced temperature increase during the subsequent delivery of laser pulses could be ascribed to the temperature-induced changes in the hair's structural properties. Simulations of the hair temperature under Nd:YAG and alexandrite irradiation indicate that the avalanche phenomenon observed in the hair suspended in air may apply also to the hair located within the skin matrix. Namely, for the same fluence, similar temperature increase was obtained also for the hair located within the skin.
Conclusion:
The observed "avalanche" effect may contribute to the reported clinical efficacy of laser hair removal and may at least partially explain the observed efficacy of the brushing hair removal procedures where laser fluence is usually low. The repeated irradiation during the brushing procedure may lead to an avalanche-like gradual increase of the hair's thermal response resulting in sufficiently high final hair temperatures as required for effective hair reduction.
... However, it was found that using a hair dryer at a distance of 15 cm with continuous motion causes less damage than drying hair naturally. 16 ...
p class="abstract"> Hair straightening is a popular hair procedure. The first hair straightening products were used for African hair. Various modes of hair straightening methods are currently being used. Temporary methods like blow drying and ironing are used for easy manageability of hair, both by modern men and women. Salon- based hair straighteners were initially permanent relaxers which, with time, evolved to formaldehyde-free hair strengthening procedures like hair Botox which is currently in trend. It improves hair manageability, increases hair strength and reduces frizz without producing much chemical damage to hair and by maintaining their natural waves, thereby producing a more natural look. We performed a thorough literature search on the topic in PubMed, consulted various hair stylists and beauty school professors prior to formulation of this article. The article aims at understanding the basic mechanisms involved in various hair straightening methods which helps us to advice patients on a wholesome care of hair. </p
... Clinically, microscopic analysis can be used as a tool to assess hair damage, as an indicator of health status [5,6], but the analysis needs to be performed under certain conditions. Hair is subjected to various physical and chemical agents, including detergents, dyes, combing, and ultraviolet rays, which will change the structure of the hair [7][8][9]. The morphological characteristics of damaged hair can be detected by qualitative methods for clinical research. ...
With increasing interest in hairstyles and hair color, bleaching, dyeing, straightening, and curling hair is being widely used worldwide, and the chemical and physical treatment of hair is also increasing. As a result, hair has suffered a lot of damage, and the degree of damage to hair has been measured only by the naked eye or touch. This has led to serious consequences, such as hair damage and scalp diseases. However, although these problems are serious, there is little research on hair damage. With the advancement of technology, people began to be interested in preventing and reversing hair damage. Manual observation methods cannot accurately and quickly identify hair damage areas. In recent years, with the rise of artificial intelligence technology, a large number of applications in various scenarios have given researchers new methods. In the project, we created a new hair damage data set based on SEM (scanning electron microscope) images. Through various physical and chemical analyses, we observe the changes in the hair surface according to the degree of hair damage, found the relationship between them, used a convolutional neural network to recognize and confirm the degree of hair damage, and categorized the degree of damage into weak damage, moderate damage and high damage.
