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1.
In the present study, the potential relationships between the microstructure and the surface properties of different cotton fibers are analyzed by inverse gas chromatography (IGC) at infinite dilution. By measuring the retention time of polar and nonpolar gaseous probes into a column containing the fibers, surface characteristics of these fibers, in particular the dispersive component of their surface energy and their surface morphological index, were determined. It is clearly shown that the presence of natural waxes on cotton fibers plays a major role on their thermodynamic surface properties, affecting the surface energy and the acid-base character as well as the morphological aspects of such fibers. Finally, it appeared that IGC is a well appropriate method for the evaluation of the surface characteristics of cotton fibers. 相似文献
2.
In order to understand the different touch senses from bamboo and cotton fibers, the surface properties of bamboo fiber, e.g., the surface free energy, the Lifshitz–van der Waals force, and Lewis acid and base components have been determined using the column wicking technique. Taking the traditional cotton linter fiber as a reference, this paper shows that both these fibers have the similar surface free energies. However, a big difference between these two fibers which has been importantly observed is that the bamboo fiber having greater Lewis acid component seems to be double than the cotton linter fiber. Since water has been found to have such surface property, it is suggested that the bamboo fiber touch in the skin of people may like the touch between water and skin of people. Meanwhile, other surface properties of these two fibers are compared. 相似文献
3.
Charles H. Fisher 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(7):1345-1375
Nature, as though aware of the importance of textiles, has long provided an abundance of fibers—plant, animal, and mineral—of different dimensions and properties. Beginning in prehistory, the natural fibers have served man's textile needs for thousands of years. The Swiss Lake Dwellers in 8000 BC cultivated flax and wove linen into fabrics. By 3000 to 2000 BC, the use of fibers was well developed, and the weaving of cotton was well established in India and Pakistan. Improvements in machines for spinning, weaving, etc., beginning in the 1700s, revolutionized the processing of fibers. Eli Whitney's invention of the cotton gin in 1793 helped cotton become king of the fibers. In recent decades the textile industry was revolutionized again by many technological developments, including the creation of synthetic and modification of natural fibers. Today the world and United States fiber markets are dominated by the natural and man-made fibers, respectively. In spite of gains by the man-made fibers, both the world and United States production of cotton increased during the decade of the seventies. 相似文献
4.
E. Giménez-Martín M. López-Andrade A. Ontiveros-Ortega M. Espinosa-Jiménez 《Cellulose (London, England)》2009,16(3):467-479
Comparative investigations of adsorption properties of chlorhexidine (CHX) on two cellulose fibers, bleached cotton and viscose,
were studied in order to obtain dry gauzes covered with known amount of this antiseptic. Adsorption isotherm results carried
out at 293 and 323 K can be described by Langmuir isotherm model, nevertheless, at high concentration correlation is better
to Freundlich isotherm. Electrokinetic potential evolution with CHX concentration, shows that initial negative zeta potential
of cotton and viscose diminish its absolute value as the concentration of the treatment increases; both fibers present an
isoelectric point at high concentration of CHX that is 0.3 mM for viscose and 0.8 mM for cotton. Electrostatic interactions
between cationic groups of CHX and carboxylic acid groups of the fibers could explain adsorption at low concentration, but
when it is higher than these values, possible hydrogen bonding between the amine groups of CHX and hydroxyl groups of cellulose
could explain increasing adsorption when it is hindered by electrostatic repulsion as it is predicted by Freundlich model,
that describes heterogeneous surface and multilayer adsorption. Adsorption kinetics isotherms reveal that the process is quick
with t
1/2 values of 5.4 min for cotton and 2.8 min for viscose. Differences in adsorption behaviour between the two fibers could be
attributed to structural differences as we have observed from estimation of CI index based on FTIR spectra. Values obtained
1.6 for viscose and 2.2 for cotton could explain that the amount of CHX adsorbed on viscose is higher than it is on cotton.
Finally desorption experiments performed with 0.01 M of NaCl solution at room temperature and pH 6 reveals the possibility
of therapeutical application of these fibers although further investigations must be done to optimize the process. 相似文献
5.
Upon swelling and dissolution, native cellulose fibers such as cotton hairs or wood fibers are rotating and contracting. Regenerated
cellulose fibers are only contracting, not rotating. Cotton hairs show two rotation mechanisms, a well known untwisting, not
seen in wood fibers, due to the unwinding of the twists initially induced by the desiccation that occurs at the end of the
growth, and a “microscopic rotation” that can also be slightly observed in wood fibers. In addition to these rotation mechanisms,
cotton hairs and wood fibers show a rolling up of their primary wall that is due to the higher elongation of the external
layers as compared to the internal layers arising during the elongation phase of the cell. Contraction originates from the
fact that the cellulose chains are in an extended conformational state due to the spinning process for the regenerated fibers
and to the bio-deposition process for native fibers. The contraction is related to the relaxation of the mean conformation
of cellulose chains from an extended state to a more condensed state. Physical as well as mechanical modeling will support
the experimental observations. 相似文献
6.
The moisture sorption behavior of white and naturally colored cotton fibers is studied by dynamic vapor sorption. Dark brown and brown fibers show a higher sorption capacity compared to beige and white fibers. The differences in sorption capacity are found to be related to the maturity and crystallinity index of the fibers. All fibers exhibited sorption hysteresis to varying degrees throughout the full relative humidity range. The variations in hysteresis behavior are mainly attributed to the differences in crystallinity index of the fibers. In addition the monolayer and polylayer moisture content is analyzed using the Hailwood Horrobin model. Monolayer sorption is most closely related to the crystallinity index and, to a lower extent, maturity of the fibers. For beige and white fibers monolayer sorption remains almost constant, whereas for darker fibers it shows a substantial increase with increasing color difference. In contrast, polylayer sorption shows a general increasing trend over the whole studied color spectrum. Also a noticeable relationship was found between the total hysteresis and the monolayer sorption. Yet such relation was less evident for polylayer sorption. This study contributes to the better understanding of the dynamic moisture sorption behavior of white and naturally colored cotton fibers. This improved understanding is important for optimal application of naturally colored cotton fibers in novel materials. 相似文献
7.
Yuan Yu Jian Wang Jidong Wang Jing Li Yanan Zhu Xiaoqiang Li Xiaolei Song Mingqiao Ge 《Cellulose (London, England)》2017,24(4):1669-1677
A kind of highly fluorescent cotton fibers, in which the luminescent carbon nanoparticles (CNPs) are generated in the lumen and the mesopores directly, have been prepared by the method of hydrothermal synthesis in situ using citric acid and urea as raw materials, and hexadecyl trimethyl ammonium bromide and tributyl phosphate as active agents. The CNPs/cotton fibers were characterized by thermogravimetry-differential thermal analysis (TG-DTA), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and X-ray photoelectron spectroscopy (XPS), respectively. The optical properties are investigated by fluorescence spectrofluorometry and PR-305 long afterglow phosphors tester. The results showed that the CNPs were self-assembled successfully in the lumen as well as in the mesopores of cotton fibers. The CNPs/cotton fibers could emit bright and colorful photoluminescence under excitation lights of different wavelengths. The afterglow decay process could be divided into fast decay and slow decay stages and the emission of CNPs/cotton fiber had two peaks at 450 nm and 570 nm respectively when the wavelength of excitation changed from 310 nm to 500 nm. The preparation of highly fluorescent cotton fibers by self-assembly method has great significance to the functionalization of cotton fibers. 相似文献
8.
A novel ZnO/cotton composite, in which ZnO nanoparticles were synthesized directly inside of the lumen and the mesopores of
cotton fibers, was fabricated via a simply two-step hydrothermal method in situ using zinc nitrate hexahydrate and hexamethylenetetramine
as raw materials. The as-obtained cotton sample was characterized by powder X-ray diffractometer, field emission scanning
electron microscopy, and energy-dispersive spectroscopy, respectively. The UV-blocking property of the as-obtained sample
was investigated by UV–vis spectrophotometry. The results showed that hexagonal wurtzite nano-ZnO with a diameter of about
30–40 nm was successfully assembled into the lumen as well as the mesoporous structure of the cotton fibers. The UV-blocking
property of the modified cotton fibers can be greatly improved by assembling nano-ZnO into the inner of cotton fibers. Comparing
with the neat cotton fibers, the UV-blocking ratio of the ZnO assembled cotton fibers inside of KBr disk could reach 80% at
300 nm and 95% at 225 nm, respectively. Therefore, it demonstrated a significant advance in protective functional treatment
and provided a potential commercialization. 相似文献
9.
Özgür Ceylan Lieve Van Landuyt Hubert Rahier Karen De Clerck 《Cellulose (London, England)》2013,20(4):1603-1612
The decomposition behavior of cotton fibers is examined using thermogravimetric analysis. The effect of the test parameters on the thermal degradation of raw cotton fibers is determined. Focus is given to the influence of water immersion on the thermal behavior of cotton fibers. For less mature fibers a clear difference is noted between the degradation profiles of the water-immersed and untreated samples. On the contrary, only a small change is noted on the degradation profile for more mature fibers after water immersion. The maturity and variations in water-soluble content of the fiber are found to be important factors influencing the thermal behavior of raw cotton fibers. Inductively coupled plasma atomic emission spectrometry (ICP-AES) is used to underpin the effect of water immersion on cotton fibers. This improved understanding for the role of maturity and water soluble constituents in thermal degradation of cotton fibers may lead to develop routes that improve thermal stability and smoldering characteristics of cotton fibers as relevant for future applications. 相似文献
10.
Unusual noncontractile motion in vivo within the fibers growing on cotton ovules was found for four cotton genotypes. Structural
investigations have shown that, in addition to the active motion related to fiber cell growth, a simultaneous spiral rotation
of the cytoplasmic membrane occurs. Due to translational growth of the fiber cell apices and spiral rotation of plasmalemma,
the fibers of cotton cultivars take on a twisted, corkscrew-like external shape. Optical microphotos illustrate the formation
process of the fiber cell wall at different stages of growth and noncontractile motion in cotton fiber cells. 相似文献
11.
Changes in sugar composition and cellulose content during the secondary cell wall biogenesis in cotton fibers 总被引:1,自引:0,他引:1
Two cotton cultivars TX19 and TX55 (Gossypium hirsutum L. cv.) were planted in the greenhouse and fibers were harvested at different stages of development. The percentage of sugars
present on the fibers was determined by High Performance Liquid Chromatography and the cellulose content was determined using
the anthrone method. The percentage of sugars (sucrose, glucose, fructose, and galacturonic acid) showed statistically significant
changes during fiber development. The decrease in the percentages of these sugars as the secondary cell wall develops was
associated with an increase in the cellulose content. It is important to point out that these analyses were done on intact
fibers, no cell wall extractions and purifications were performed. 相似文献
12.
The extent of stacking and twin faults has been estimated in different varieties of cotton fibers grown in the Karnataka State
of India using wide-angle X-ray scattering (WAXS) data. Further, the microstructural parameters such as crystal size 〈N〉 and lattice strain (g in %) have been determined by a whole powder pattern fitting technique developed by us. In all these cases we note that the
stacking and twin faults are quite significant in determining the properties of cotton fibers and their microstructural parameters. 相似文献
13.
In this research, enzymatic treatment as an environmental friendly process has been used for recycling process of old cellulosic
wastes such as cotton, viscose, and lyocell. Cellulase hydrolyses cellulosic chains and shortens cellulosic fibers. This study
investigates to detect the optimum enzyme concentration and time of treatments for suitable changes of length and weight loss.
The main purposes of this article are shortening of cellulosic fibers and evaluating of enzymatic treatment in different kind
of cellulosic fibers. According to the data of experiments, with the increase of enzyme concentration and the treatment time,
the length and weight loss percentage of the cellulosic fibers has been decreased. The length and weight loss percentage of
treated viscose is more than that of lyocell and cotton fibers. Optimized condition, reaction time, and enzyme concentration
have been determined by mean length of treated cellulosic samples. Suitable longitudinal distribution of fiber for papermaking
industries is in the range of 0 to 4 mm. Optimum enzyme concentration and treatment time for recycling cotton, lyocell, and
viscose fibers are 2% and 48 h for cotton and lyocell and 0.5% and 48 h for viscose, respectively. According to the data of
experiment, the length of treated fibers is appropriate for its usage as a raw material in papermaking industries. 相似文献
14.
15.
K. R. Krishna Iyer P. Neelakantan T. Radhakrishnan 《Journal of Polymer Science.Polymer Physics》1969,7(6):983-992
Interferometric studies have been made on cotton fibers as well as on twisted nylon filaments. The results so obtained provide strong evidence that the fibrils in the cotton fiber become less inclined to the fiber axis as one proceeds from the surface to the core. Also, studies on twisted nylon filaments by the fiber refractometer and Becke line techniques indicate that the latter, as practiced in this laboratory, does give values of refractive index which are heavily weighted towards the fiber periphery. 相似文献
16.
A convenient method for in situ synthesis of silver nanoparticles was developed to realize the multifunction of cotton. The silver nanoparticles were obtained through reduction of silver ions by cotton under basic condition at room temperature. The as-synthesized silver nanoparticles achieved the coloration of cotton fibers. Heating increased the color strength of cotton fibers with silver nanoparticles. Mercerization treatment as a common finishing process enhanced the properties of cotton fibers modified by silver nanoparticles. The mercerized cotton exhibited brighter color and had very good colorfastness to washing. The cotton fibers treated with in situ synthesized silver nanoparticles possess strong antibacterial activity with excellent washing durability. 相似文献
17.
Zhen Dong Xiuliang Hou Fangfang Sun Li Zhang Yiqi Yang 《Cellulose (London, England)》2014,21(5):3851-3860
Textile grade long natural cellulose fibers with fineness of 27 dtex have been extracted from bark of cotton stalks by a combination of steam explosion, potassium hydroxide and peroxide treatments (explosion–KOH–H2O2). It was reported that natural cellulose fibers from bark of cotton stalks had significantly better mechanical properties than those from other lignocellulosic agricultural byproducts such as rice and wheat straws. Fibers from bark of cotton stalks were used to reinforce thermoplastic composites but could not be spun into yarns for textile applications due to their high fineness value (around 50 dtex) and/or low aspect ratio (around 660). In this research, barks of cotton stalks were treated using three methods, including steam explosion, a combination of steam explosion and potassium hydroxide treatments (explosion–KOH) and explosion–KOH–H2O2. The morphology, composition, carding yield, crystalline structures and tensile properties of three different cotton stalk fibers were analyzed. Results showed that cotton stalk fibers extracted by explosion–KOH–H2O2 had the lowest fineness value of 27 dtex and moderate aspect ratio of 1,150 in three kinds of fibers. The fibers also had most clean and smooth surfaces, highest carding yield of 68.6 %, and highest cellulose content of 82.1 wt% due to effective removal of non-cellulose impurities. Moreover, the fibers had tensile properties close to cotton fibers. Overall, the cotton stalk fibers presented a better potential to be used as textile fibers than those reported by previous researches. explosion–KOH–H2O2 could be an efficient method for exploring textile applications of bark of cotton stalks. 相似文献
18.
基于聚多巴胺(PDA)的化学性质和树莓状纳米粒子的粗糙结构,以聚多巴胺包覆的棉纤维为基底,制备了具有多重粗糙度的树莓状超疏水多孔复合棉纤维材料.通过扫描电子显微镜观察树莓状超疏水多孔复合棉纤维表面的微观形貌,PDA-SiO2纳米粒子稳定地固定在聚多巴胺涂覆的棉纤维表面.经过氟化改性的树莓状超疏水多孔复合棉纤维具有超疏水性,水接触角为158.2°,油接触角为0°.油/水分离实验结果表明,树莓状超疏水多孔复合棉纤维对己烷/水混合物的分离效率可达99.4%以上,使用20次后仍维持较高的分离效率.同时,其具有较高的溶剂吸附能力(13~34 g/g)、重复使用性及机械稳定性,吸油能力可与硅气凝胶相媲美. 相似文献
19.
Ya-Hong Mao Yu Guan Qing-Kang Zheng Xi-Ning Feng Xiu-Xing Wang 《Cellulose (London, England)》2011,18(2):271-279
Adsorption thermodynamic and kinetic study of disperse dye on cotton fiber modified with tolylene diisocyanate derivative
was carried out under the condition of pH value 6.0 ± 0.2, initial dye concentration 0.01–3.0 g/L and liquor ratio 2,000:1.
The result showed the equilibrium adsorption isotherm of disperse dye on modified cotton fiber was Langmuir—Nernst mixed Model and the saturated adsorption capacity of the turning point was 7.1429 mg/g. The calculation of the thermodynamic
parameters indicated that the Van der Waals’ forces played a major role between the disperse dye and the modified cotton fiber,
and the adsorption of disperse dye on the modified cotton fiber was exothermic process. Compared with the diffusion coefficient
and the activation energy of disperse dye on various fibers, the disperse dye diffusion in modified cotton fiber was more
difficult than that in original cotton. Meanwhile, it was found that the adsorption kinetics of disperse dye on modified cotton
fiber was well agreed with a pseudo second-order kinetic model. 相似文献
20.
P. K. Chidambareswaran V. Sundaram Jai Prakash N. C. Verma B. B. Singh 《Journal of polymer science. Part A, Polymer chemistry》1971,9(9):2651-2658
With a view to assessing the role of chemical substitutions in the modification of radiation effects on cotton fibers, the induction and post-irradiation behavior of free radicals in γ-irradiated pure, mercerized, benzoylated, and allylated cottons have been investigated by ESR spectroscopy. While mercerization and allylation were found to influence both the nature and yield of radicals, benzoylation reduced only the yield. These substitutions, which have been found to protect cotton fibers against radiation damage, therefore act differently at the molecular level. 相似文献