Diffusion behavior of reducing agents into keratin fibers using microspectrophotometry

To investigate the penetration of thioglycolic acid (TG), thiolactic acid (TL), and L ‐cysteine (CYS), into keratin fibers, cross‐sectional samples of virgin white human hair treated with TG, TL, and CYS were prepared. A new method for analyzing the diffusion behavior of reducing agents into human hair was developed. The diffusion pattern of reducing agents into human hair, which cannot be determined by optical microscopy, can be determined by the method developed. The method involves treating virgin hair fibers with TG, TL, and CYS. After the treatment, the cross‐sectioned hair samples were dyed with methylene blue and the cross‐sectional intensity scans were measured at a wavelength of 664 nm (λ_max of methylene blue) with a microspectrophotometer. The three different diffusion patterns from the three reducing agents were obtained. The penetration of TG and TL into virgin human hair clearly increased by increasing the treatment time and pH. On the other hand, the penetration of CYS was less than TG and TL (CYS could not penetrate into the cortex region of the virgin human hair). Also, the diffusion pattern of TG showed Fickian type characteristics. The apparent diffusion coefficient of TG into human hair at pH 9.0 determined from the TG concentration profile was found to be 10^?9 cm²/s. On the other hand, the apparent diffusion coefficient of TG into human hair at pH 7.0 was 10^?10 cm²/s, and thus, the apparent diffusion coefficient of TG depended on the pH of the TG solution. From these experiments, we have concluded that the diffusion patterns of the three reducing agents in this study depended on the electrostatic interaction between the human hair and the reducing agents. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1131–1138, 2004     

Diffusion behavior of poly(ethylene imine) into keratin fibers using microspectrophotometry

In order to investigate the diffusion behavior of poly(ethylene imine) (PEI) into keratin fibers, cross‐sectional samples of bleached white human hair treated with PEI were prepared. We were successful in developing a method for analyzing the diffusion behavior of PEI into human hair, which to our knowledge is a first. The diffusion pattern of PEI into human hair, which cannot be determined by optical microscopy, can be determined by our method. After the treatment, the cross‐sectioned hair samples were dyed with Orange II and the cross‐sectional intensity scans were measured at a wavelength of 487 nm (λ_max of Orange II) with a microspectrophotometer. In our method, the diffusion pattern of PEI at pH 11.1 showed Fickian type characteristics. This suggests that the diffusion coefficient of PEI is essentially independent of the PEI concentration. By calculating the diffusion coefficient from the PEI concentration profile, the diffusion coefficient of PEI [number‐average molecular weight (M_n) = 300 and 600] into the bleached human hair was found to be on the order of 10^?10 cm²/s. In addition, the diffusion coefficient of PEI (M_n = 600) with urea added increased twofold in comparison with that of PEI without urea added. This experiment demonstrated that urea acts as a penetration accelerator for PEI. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 65–71, 2005     

Chemical modification of keratin fibers using 2‐iminothiorane hydrochloride

For the purpose of improving the properties of keratin fibers by chemical modification, we attempted to introduce new disulfide (–SS–) groups into hair using 2‐iminothiorane hydrochloride (2‐IT). After the evaluation of the setting ability of human hair, the waving permanence (66%) of our proposed permanent hair‐setting process clearly improved compared with that of a conventional permanent hair‐setting process (48%). Next, it became clear that new –SS– groups were created in the human hair samples as a result of introducing and then oxidizing new –SH groups. This –SS– content in the hair samples was estimated by employing FT‐Raman spectroscopy. By examining the Raman bands of the treated and untreated hair, it was seen that each band of treated hair did not change, except for the increase of the –SS– groups. This suggests that hair damage does not occur as a result of the investigated treatment. From these experiments, the chemical modification of keratin fibers using 2‐IT was clearly effective for a permanent hair‐setting process. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3646–3651, 2003     

NBD-Cl与头发表面半胱氨酸残基的相互作用研究

在碱性条件下用巯基乙酸使头发表面角蛋白质胱氨酸转为半胱氨酸残基,再以荧光试剂NBD-Cl着色处理头发。采用荧光光谱法和衰减式全反射傅立叶红外光谱法研究头发表面半胱氨酸残基与NBD-Cl的相互作用。结果表明该相互作用受处理溶液介质pH的影响,随溶液pH2～5改变λem-max发生红移。介质pH3处理的发样NBD-Cl取代位点可能为半胱氨酸上巯基。介质pH3处理的发样表面衰减式全反射红外光谱结果出现硝基对称伸缩振动峰,进一步支持NBD-Cl与头发表面半胱氨酸发生特异性结合的结论。NBD-Cl浓度改变对NBD-Cl与头发表面基团(巯基或胺基)反应的选择性无影响。实验结果表明Cu2+、Pb2+、Fe3+减弱NBD-Cl与头发表面半胱氨酸残基的相互作用,Ni2+的存在基本无影响。     

Raman spectroscopic analysis of L‐phenylalanine and hydrolyzed eggwhite protein penetration into keratin fibers

To investigate the penetration of amino acids and hydrolyzed protein derived from eggwhites (HEWP) into keratin fibers, the structure of cross‐sectional samples at various depths of virgin white human hair treated with L ‐phenylalanine (Phe) and bleached black human hair treated with HEWP was directly analyzed without isolating the cuticle and cortex using Raman spectroscopy. The hydrophobic amino acids clearly penetrated into the virgin white human hair, while hydrophilic amino acids did not penetrate at all. The Phe hydrophobic amino acid content at various depths of the virgin white hair increased by performing the Phe treatment (at 50°C for 16 h), indicating that Phe deeply penetrated into the virgin human hair. Also, the disulfide (? SS? ) and random coil contents at various depths of the bleached human hair increased by performing the HEWP treatment, indicating that HEWP also deeply penetrated into the bleached human hair. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

还原法提取人发角蛋白

以β-巯基乙醇为还原剂,尿素为角蛋白变性剂,月桂硫酸钠(SDA)为角蛋白溶液稳定剂,研究了人发纤维中角蛋白的还原法提取工艺。最佳提取工艺条件为:β-巯基乙醇质量分数3%、SDS质量分数2%、尿素浓度7mol/L、反应前溶胀时间2 h、反应温度45℃、反应时间12 h。此时人发溶解率达58%~60%,工艺重复性好。     

New method of dyeing keratin fibers using poly(ethylene imine) and its coloring mechanism

To improve the colorability of keratin fibers at lower temperatures, we developed a novel coloring method using poly(ethylene imine) (PEI) as a counterion reagent (human hair was treated beforehand with a PEI solution and then was colored with an acid dye). As a result of this new method, the coloring and color fastness to shampooing clearly improved with respect to the usual method. Next, to study the coloring mechanism with PEI, we investigated the penetration of PEI and Orange II into bleached human hair by optical microscopy. The results showed that the penetration of PEI and Orange II into bleached human hair increased with an increasing PEI treatment time and with a decreasing PEI molecular weight. With these experiments, we demonstrated that PEI, which penetrated the cortex region, exerted counterionization on Orange II, thereby increasing the penetration of Orange II into bleached human hair. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3806–3810, 2003     

Influence of urea on the coloring ability of a low‐temperature coloring method of keratin fibers using polyethyleneimine

For the purpose of improving the coloring ability of keratin fibers at a lower temperature, we investigated the influence of urea on the coloring ability of a low‐temperature coloring method using polyethyleneimine (PEI) as a counter ion reagent (the human hair was previously treated with a PEI solution, and then was colored with acid dye). The coloring and color fastness to shampooing of the hair pretreated with a PEI solution containing urea clearly improved compared with those pretreated with a PEI solution not containing urea. Also, we prepared cross‐sectional samples of the treated hair and investigated the penetration of PEI and Orange II into human hair by optical microscopy. The results showed that the penetration of PEI and Orange II into human hair pretreated with a PEI solution that contained urea clearly increased compared with those pretreated with a PEI solution that did not contain urea. From these experiments, we concluded that urea acts as a penetration accelerator for PEI; and PEI, which penetrates deeper into human hair by adding urea, exerts counter ionization on Orange II, thus increasing the penetration of Orange II into human hair and thereby improving the coloring ability. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3827–3834, 2004     

Crosslinking structure of keratin. I. Determination of the number of crosslinks in hair and wool keratins from mechanical properties of the swollen fiber

Hair and wool keratin fibers which had been treated with an 11 M LiBr solution containing N-ethyl maleimide showed typical rubberlike elasticity in a solution composed of equal volume of 8 M LiBr and diethylene glycol mono-n-butyl ether. Stress–strain curves and equilibrium force–temperature relations were measured for swollen hair and wool fibers. The non-Gaussian effects on deformation and the energy component in retractive forces were analyzed. On the basis of rubber elasticity theory, a method for estimation of the number of mechanically effective crosslinks in keratin fibers was proposed. A linear relationship between the crosslink density and the disulfide content was obtained from the data for a variety of keratin fibers (i.e., two different human hairs, horse hair, and 17 different wools). From the results of thermodynamical and non-Gaussian treatments for swollen keratin, it was suggested that the swollen fiber consists of a two-phase structure: a mechanically stable phase of higher crosslinked domains and rubbery phase with lower crosslink density. It was further found that considerable amounts of nondisulfide covalent crosslinks are present in wool and hair keratins.     

Electrochemical behaviour of tin in bicarbonate solution at pH 8

The anodic oxidation of tin in 0.1 to 1M bicarbonate solutions at pH 8 has been studied. The process may be divided into three potential regions: (1) a short active dissolution (Tafel) region; (ii) a dissolution-precipitation region; and (iii) a large region of electrode passivity. The rate-determining step of the reaction in the active-dissolution region is attributed to the diffusion of an ionic species into the solution, the diffusing species being generated at the metal surface. In the region of the first oxidation peak, the reaction rate is controlled by diffusion of CO ₃ ^2– species in solution. When the potential becomes more positive than –0,1 V_sce, a highly passivating (most likely SnO₂) film is formed on the electrode surface.     

Diffusion of biological molecules through hollow chitosan fibers

Hollow chitosan fibers were tested for the diffusion of a series of biological macromolecules, including amino acids, vitamins, and antibiotics. The hollow fibers were immersed in the permeant solution, and water was circulated and recycled inside the lumen of the fiber. The concentration of the permeant in the hollow fiber loop was analyzed online by ultraviolet–visible spectrophotometry. The effect of process parameters such as the concentration, pH, and flow rate was tested. The permeability coefficient was calculated from the permeability. The limited influence of the flow rate indicated that resistance to film diffusion (at the surface of the fiber) was not the rate‐limiting step: the limiting step remained diffusion through the membrane. The pH would be expected to influence the protonation of chitosan amine groups and the acid–base properties of the permeant; however, the diffusion profiles were little affected by this parameter. The impact of pH on the permeability coefficient decreased in the following order: tryptophan > chloramphenicol > vitamin B12. The change in the concentration of the permeant had a limited impact on the permeability coefficient. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Cover: Macromol. Mater. Eng. 3/2005

Summary: A novel human hair protein hybrid fiber was developed by combining (i) the high‐efficiency extraction technique for preparing human hair proteins and (ii) the watery hybridization spinning method using gellan and chitosan. The resulting human hair protein‐gellan‐chitosan hybrid fibers are conveniently produced by simply mixing the 7–35 wt.‐% human hair protein‐1.0 wt.‐% gellan aqueous solution and the 1.0 wt.‐% chitosan‐0.15 M acetic acid solution at 50 °C, followed by pulling out to spin the human hair protein‐gellan‐chitosan ternary complex thus formed at the aqueous solution interface. By use of this simple procedure and ambient spinning condition, the human hair proteins were successfully incorporated into the fiber matrix of gellan‐chitosan, without any denaturation and degradation. The hybrid fiber can also be recognized as a new type of the regenerated human hair keratin fiber, because of its high purity and content of human hair keratin types I and II. Mechanical strength of the human hair protein‐gellan‐chitosan fiber varies from 108 to 153 MPa, depending on the contents of the human hair proteins. SEM observation revealed that the incorporated human hair proteins were found as the particles (1–10 μm) on the fiber surface. The type I and II keratins in the fiber matrices were rapidly biodegraded by chymotrypsin within 30 min, and the digested fragments slowly released from the fiber matrices. Thus, the human hair hybrid fiber is a very promising material to have a broad spectrum of applications as the engineering fibers, particularly for the medical uses, because the human hair proteins are easily available, biocompatible, and bioresorbable materials.

Gellan‐chitosan hybrid fiber (a), human hair protein‐gellan‐chitosan hybrid fiber (b).     

Selective catalysis of μ-oxo-bismetalloporphyrins for 2-methylbutane oxidation with PhIO under mild conditions

Fourteen μ-oxo-bisironporphyrins and nine μ-oxo-bismanganeseporphyrins were synthesized, and their selective catalysis for the oxidation of the secondary and tertiary carbon–hydrogen bonds of 2-methylbutane with PhIO were also studied. The ratio of the relative reaction selectivity of tertiary carbon–hydrogen bonds to secondary carbon–hydrogen bonds was 3:1 when ironporphyrins were used as catalysts, and 4:1 when manganeseporphyrins were used as catalysts. The research showed that the substituents on the porphyrin rings influenced the catalytic selectivity of metalloporphyrins for the oxidation of the secondary and tertiary carbon–hydrogen bonds as well as the reaction rate. Whether ironporphyrins or manganeseporphyrins, the electron-attracting groups on porphyrin rings increased the catalytic selectivity of metalloporphyrins for the tertiary carbon–hydrogen bonds and the reaction rates, however, the electron-releasing groups increased the catalytic selectivity of metalloporphyrins for secondary carbon–hydrogen bonds, but reduced the reaction rates.     

Characterization and modeling of the moisture diffusion behavior of natural fibers

Natural fibers have good properties to be used as reinforcement in composite materials. The main issue is their hydrophilic behavior. So we propose here to investigate the diffusion phenomenon in such fibres. First, a brief characterization of four vegetal fibers has been achieved. We show that all fibers have a similar composition and structure despite their different origin. Then, their moisture diffusive behavior was investigated. The samples were submitted to hygro‐thermal aging either in total water immersion at room temperature or in an environmental chamber at 80% relative humidity and 23°C. Various predictive models were used to simulate experimental curves. Results show that all fibers exhibit a similar diffusive behavior in a same environment. In immersion, specimens show anomalous absorption kinetics and Langmuir theory actually describes very well the diffusion kinetics in such conditions, whereas the same fibers follow a Fickian diffusion when they are exposed to vapor during relative humidity aging. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

鸡毛角蛋白的制备及其护发性能

采用还原C法提取了鸡毛角蛋白,考察了反应时间和温度对角蛋白产率和黏度影响。采用傅里叶变换红外光谱仪对提取物进行了表征。利用透析得到的角蛋白对头发进行处理,考察了其保湿及抗紫外线的效果。结果表明:当温度70℃、时间4 h时能够制得产率和黏度均较为理想的角蛋白溶液。红外谱图表明提取物为β-折叠结构的角蛋白。经角蛋白处理后的头发具有较好的保湿性,紫外谱图表明浓度6.7 g/L的羽毛角蛋白溶液对波长200～350 nm的紫外线有较好的吸收作用。     

An FTIR/ATR in situ study of sorption and transport in corrosion protective organic coatings: Paper 2. The effects of temperature and isotopic dilution

A detailed temperature variation (18–50 °C) FTIR/ATR study of sorption and desorption of water into a series of cured epoxy resins has been reported. For higher temperatures (35–50 °C) the data were modelled with a single Fickian diffusion equation, giving an increased D as the temperature increased and an activation energy (E_A) in the 55–60 kJ mol⁻¹ region. At lower temperatures (18–35 °C)—well-below the T_g—a two-stage sorption equation was needed and the apparent E_A was negative. This is probably associated with changes in water clustering among the distributed ‘voids’ in the glassy polymer associated with chain relaxation at extended times. The use of D₂O as a penetrant allowed diffusion coefficient measurements for highly dense epoxy matrices, where FTIR/ATR cannot detect the ν(OH) band of water over and above the residual polymer–OH groups (in the dry state). The data for the D₂O studies were notably influenced by isotopic exchange; which was found to be a diffusion controlled process, even in a polymer matrix.     

Solid-phase polymerization mechanism of poly(ethylene terephthalate) affected by gas flow velocity and particle size

Experimental studies on the solid-phase polymerization (SPP) of poly(ethylene terephthalate) (PET) for different particle sizes at temperatures of 190–220°C were carried out at different gas flow velocities. The SPP mechanism of PET changes under different operating conditions. At a given gas flow velocity, the SPP reaction mechanism for a large-sized sample changes from chemical reaction control to interior diffusion control with increasing temperature. At a given reaction temperature, the SPP reaction control mechanism for a small-sized sample changes from surface diffusion control to chemical reaction control with increasing gas flow velocity. At a given reaction temperature and gas flow velocity, the SPP reaction mechanism changes from interior diffusion control to surface diffusion control with decreasing particle size. The SPP reaction rate is not determined by a single control mechanism but by both diffusion and chemical reactions in the temperature range of 200–220°C. The primary control mechanism can be discerned based on the operating parameters.     

Über Sorptionsvorgänge von Carbonsäuren an Haarkeratin

The Sorption Process of Carboxylic Acids on Hair Keratin Methods for the measurement of adsorption of carboxylic acids by hair keratin were worked out. The different methods show good agreement in their results. The adsorption of monochloroacetic acid was determined in relation to its concentration, time of action and pH value. Also the adsorption of homologous and variedly substituted carboxylic acids from aqueous as well as absolute propanol solutions was compared to each other. For the adsorption of carboxylic acids by hair keratin, the dissociation, chain length, substitution and solvent are of utmost importance.     

Low-temperature oxidation of soot

The oxidation rate of propane soot over the temperature range (770–1250 K) has been measured using two methods. These were direct measurements of the burn-out of soot produced by a laminar diffusion flame, and a thermal gravimetric technique using collected soot. The reaction order with respect to oxygen (over the range 1–20 kPa) was determined at a variety of particle temperatures and found to lie between 0 and 0.65. The intrinsic reaction rate at an oxygen partial pressure of 101 kPa was found to be given by ρ_i = 1.05 exp(− 143.5/RT) units where the activation energy is given in kJ/mol. Some values for the oxidation rate of methane soot are also given.     

羊毛角蛋白液涂覆处理涤纶的亲水性研究

利用三羧乙基膦(TCEP)和亚硫酸氢钠溶解羊毛制备羊毛角蛋白溶液;采用羊毛角蛋白液涂覆处理涤纶,改善涤纶的亲水性,结果表明:采用体积分数为10%的羊毛角蛋白液涂覆处理涤纶织物,织物平均增重率大于9%,织物的回潮率由0.57%提高到7.16%.吸湿性明显改善;采用TG酶交联角蛋白液涂覆处理织物,可改善其耐洗性;TC酶交联角蛋白的最佳工艺为:TG酶用量1 g,交联时间5 h,交联液pH值为7;经扫描电镜观察和X射线光电子能谱分析,羊毛角蛋白对涤纶有很好的粘附