• Applied Microscopy
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• v.38 no.3
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• pp.251-257
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• 2008

Human hair experience tensile forces during combing, bleaching and permanent dyeing processes. We have used rheometer to characterize bleached hair tensile response. Also, we investigated to morphological changes after tensile test of virgin hair and bleached hair using scanning electron microscopy. In tensile test, the tensile strength of virgin hair was $14.66g/cm^2$. They were measured as $12.95g/cm^2$, $12.61g/cm^2$ and $11.43g/cm^2$ for after the first, the second and the third trials of bleaching were done, respectively. Virgin hair had a higher tensile force than bleached hair. Tensile strength got lowered as more bleaching trials were done. In the observation of scanning electron microscopy, the fracture and lift-off of the cuticle outer layer were shown in virgin hair and bleached hair. The bleached hair were more lifted off at the outer cuticle layer than virgin hair. Consequently, chemical damage of bleaching agent caused weakening of the outer cuticle in the hair.

• Applied Microscopy
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• v.39 no.1
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• pp.49-56
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• 2009

In this study, we investigated tensile properties and ultrastructural changes of straight permed hair using the rheometer and the scanning electron microscopy. First, we compared the morphological characteristic between the virgin hair and the straight permed hair after testing tensile strength. Cuticle cells were heavily lifted off in straight permed hair than in the virgin hair. Cuticle cells were separated by the destruction of intercellular membrane complex and no destruction or damage were found in cytoplasm. In the comparative test for tensile characteristic between the virgin hair and the straight permed hair, tensile distance of the straight permed hair was decreased by 24.5% or 3.05 mm than the virgin hair. The tensile strength was decreased by 34.63% or $5.62\;g/cm^2$ and the maximum stress by 34.59% or 56.12 g. As a result, the tensile property dropped to the lowest level with the straight permed hair than with the bleached hair or the permanent dyed hair of previous studies.

• Journal of the Korean Society of Fashion and Beauty
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• v.4 no.2 s.8
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• pp.15-21
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• 2006

In this research, I chose and studied colorless hair manicure, which is well known for its useful point and supplement damaged hair glossy, luster, elastic and soft one. Also I studied and found hair protection effect by the management time of colorless hair manicure products, as below. Both level 3 and level 6 hairs, when they get damaged after dyeing, both hairs' strength and enlargement are affected. Manicuring two weeks after dyeing is more effective way than manicuring right after dyeing. So, in case of making good hair quality in manicuring dyed hair, it's more effective to manicure right after dyeing to both level 3 and level 6 hair. To complement hair's damage, however, manicuring two weeks after dyeing is the best effective way.

• Applied Microscopy
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• v.38 no.4
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• pp.339-345
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• 2008

In this study, we compared the stress and tensile strength of the hair treated with oxidative permanent dye with those of virgin hair. We investigated the fine structure of the hair section after the tensile test using scanning electron microscopy. The tensile strength of the virgin hair was measured as $14.66\;g/cm^2$, tensile energy was $108\;erg/cm^2$, and the maximum stress was 146.64g. Those of the dyed hair were $13.69\;g/cm^2$, $89.62\;erg/cm^2$ and 136.90 g, respectively. The differences in the tensile strength, the tensile energy and the maximum stress were $-0.97\;g/cm^2$, $-18.38\;erg/cm^2$, -9.74 g, respectively, which showed that the dyed hair had less elasticity and strength than the virgin hair. In the scanning electron microscopy investigation of the damaged hair after the tensile test, lift-off of the cuticle outer layer were shown in both virgin hair and dyed hair, which was more severe in the dyed hair than the virgin hair. Adjacent cuticular cells of the cuticle layer were separated by the destruction of intercellular membrane complex. The macrofibrils were exposed and separated from the cortex torn by tensile strength.

• Applied Microscopy
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• v.39 no.4
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• pp.365-371
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• 2009

This study was investigated to observe morphological changes of two pre-astronauts' hair, male and female by electron microscopy and to analyze its tensile strength by using rheometer. The surface of those two pre-astronauts' hair, which were very rough and irregular, contained separated scales and destroyed remnants of cuticular cells. Also, there were many holes on the cytoplasm of the cuticular cells which forms the cuticle layer. The destruction begins when the endocuticle where the holes form gets destroyed. And then, The tensile strength of female pre-astronaut's hair was 14.60 mm which is 10% reduced, compared to that of the normal healthy hair. Thus, this result thought to be due to the prolonged change of the biorhythm and psychological instability of the pre-astronauts.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.44 no.2
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• pp.133-139
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• 2018

Chemically damaged hair is vulnerable to external stimuli in daily life due to the weakened physical properties of the hair strand itself. The purpose of this work was to determine whether chemical conjugation between hair keratin proteins restores tensile strength and thus results inpreventing further deterioration under repeated combing. A model damaged hair tress was produced by a typical perm-process. Then, it was internally crosslinked by the bifunctional crosslinker (3-aminopropyl)triethoxysilane (APTES), via both silane coupling and carbodiimide chemistry. Physical properties, including tensile strength, Young's modulus, and plateau stress, were measured to verify the effect of internal crosslinking, and the existence of crosslinking was verified by Fourier transform infrared (FT-IR) spectroscopy. The degrees of hair breakage and split ends were evaluated by repeated combing-drying tests. Physical properties of chemically damaged hair were restored by internal crosslinking. Successful crosslinking of APTES via both silane coupling and carbodiimide chemistry was verified by FT-IR spectra. Prevention of breakage and split ends after repeated combing with heat was observed. Human hair can be weakened by chemical damage including perm-processing, so restoring such properties is a major issue in the hair care industry. This work shows that internal crosslinking of damaged hair via chemical conjugation would be a potent method to restore the healthy hair.

• Journal of the Korean Society of Clothing and Textiles
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• v.30 no.12 s.159
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• pp.1708-1713
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• 2006

The purpose of this study is to investigate the efficacy of juglone, which shows hish affinity to wool, for hair dyeing as a natural dye. Before dyeing hair with juglone, virgin hair was bleached by a conventional method using hair shops in the city. In order to study the dyeing properties of juglone on hair, the effects of dyeing conditions on dye uptake, color, tensile strength, and morphology were investigated. And the effect of Fe-mordanting on color change was also investigated. Dye uptake changed marginally as dye concentration increased in the range of 0.02-0.04g. Dye uptake increased progressively is dyeing time increased in the range of 10-20 min. Juglone produced YR colors on hair and the color of dyed hair got duller as juglone concentration increased. The hair was little damaged by bleaching, but cuticles were melted and stripped away by dyeing for longer time. Tensile strength retention decreased up to 65% at 20 min dyeing. Simultaneous mordanting with Fe did not improved dye uptake, but led to darker brown color compared with unmordanted hair.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.42 no.3
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• pp.279-284
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• 2016

In this study, facial hair weakening ability of urea and anti-oxidants for shaving was investigated. The hair weakening ability and cross-section increase of hair depends on concentration of urea. The results showed that urea affects swelling of hair and this is related to the hair weakening ability. Anti-oxidants showed outstanding weakening ability despite of their low concentrations by breaking disulfide bond in facial hair. To evaluate the suitability of urea and anti-oxidants for facial cosmetic products, in vitro safety tests were proceeded. The results showed that urea and glutathione were safe for face. As a result, urea and glutathione were safe and outstanding as hair weakening agent for cosmetic shaving products.

• Journal of the Korea Convergence Society
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• v.11 no.8
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• pp.223-228
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• 2020

The need to steadily manage healthy hair for a beautiful hairstyle is emerging, and it is time to develop hair cosmetics using natural antioxidants that are harmless to the human body according to the needs of the times. Therefore Max. Load, Max. Stress, Max. Elongation, and breakage on the hair coated with the extract of Ginkgo biloba L. According to the Break Load, Break Stress, Break Elongation, Max. Various convergence property experiments such as modulus and Tangential modulus values were conducted. As a result of research, the hairs coated with Ginkgo biloba extract had an overall increase in intrinsic properties including tensile strength compared to the control group. Through this study, we intend to study the potential of Ginkgo biloba L. as a useful material for hair cosmetics such as permanent wave preparations as well as health supplements and medicines that have been released, and we expect that it will be provided as useful research data for the subsequent development of various hair cosmetics.

• Journal of the Korean Applied Science and Technology
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• v.39 no.5
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• pp.614-622
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• 2022

This study attempted to investigate the effect of manufacturing a formulation with lavender extract and applying it to damaged hair. The experimental material was prepared by adding 0 g, 3 g 6 g, and 9 g of lavender extract to the perm base agent. The prepared formulation was applied to four damaged hair samples and compared and analyzed. As a measurement method for the effect on damaged hair, tensile strength, absorbance using methylene blue, and gloss were measured. Statistical analysis was conducted for the reliability of the research results. The tensile strength measurement results showed that the tensile strength of the sample applied with a formulation containing 6 g and 9 g at 8 levels increased, affecting damaged hair. As a result of absorbance analysis using methylene blue, it was found that the absorbance of all samples applied by adding extracts decreased, affecting damaged hair. The gloss measurement results showed that the addition of 9 g affected the damaged hair. In conclusion, it can be seen that lavender extract affects damaged hair, so it is considered to have an effect of improving Damage hair.