Surface Modification Of Wool Research Articles

The Absorption Accelerating Behavior of Surface Modified Wool: Mechanism, Isotherm, Kinetic, and Thermodynamic Studies

ABSTRACT Even though wool has excellent fabric properties, its low absorption capacity hinders its efficient application in the textile industry and material field. Surface modification is one of the efficient ways of improving its inherent properties. However, the effect of surface modification on its absorption properties is not well understood. Herein, surface modification of wool was performed using deep eutectic solvent method. Several physical and chemical properties of the modified wool including chemical bonds, surface topography, and absorption capacity were analyzed. FTIR revealed that surface modification retained keratin molecular structure but only cleaved disulfide bonds. The second-derivatization of FTIR spectra further indicated that the secondary structure was also retained. SEM and EDS analyses revealed that scale modification etched the wool surface. Together, these changes improved the absorption capacity of wool. BET further revealed that surface modification increased the pole size of wool, a property that improves the adsorption capacity. Further analyses on diffusion coefficient, adsorption isotherm, adsorption kinetics, and thermodynamic parameters at a lower temperature revealed that surface modification followed Langmuir to Freundlich isotherm and pseudo-first-order model to pseudo-second-order model transformation. In particular, the adsorption content, rate and diffusion coefficient increased with decrease in the entropy and enthalpy of wool.

Enhancing surface performance of wool using reduced ionic liquid

Wool surface modification is essential for its application in the textile industry. In this work, a novel approach using reduced ionic liquid (IL) was applied to modify the surface of wool and enhance surface-related properties of wool for overcoming the unsustainable drawbacks in the present methods. The results from the surface morphology indicated that the wool was gradually dissolved from the outside to the inside of the fiber. The treated wool was characterized using the X-ray photoelectron spectroscopy (XPS), fluorescence microscopy and the Allwörden reaction. Moreover, felting shrinkage, mechanical properties, and dyeing properties of the treated wool were analyzed. Disulfide bonds were cleaved during the process from XPS test. The Allwörden reaction and fluorescence analysis showed damaged scale layer on the wool surface and an intact fiber main body with an acceptable loss of mechanical properties. Compared with the untreated wool, the anti-felting properties and dyeing performance improved due to the cleavage of disulfide bonds and the removal of the lipid layer, indicating that the treatment could modify the wool surface. Overall, the study supports a novel, facile and highly efficient approach for preparing a value-adding natural protein fiber with a potential for large-scale production.

Surface Modification of Wool Fabric with Chitosan and Gamma Radiation

Surface modification of wool was done with chitosan, gamma radiation and combined chitosan/gamma radiation to analyze how polymer loading%, k/s value, dye uptake% and wash fastness property vary of the dyed fabric. In this investigation scoured and bleached knitted wool fabric was treated with 0.1%, 0.3%, 0.5%, 0.7% and 1% chitosan and polymer loading was found as of 1.21%, 1.38%, 0.32%, 0.14% and 0.48% respectively. It was found that polymer loading % increase significantly with the decrease of chitosan concentration % up to a certain limit. Some samples were irradiated with 5kGy, 10kGy, 20kGy and 50kGy gamma radiation individually. Combined chitosan/gamma treatment was carried out by treating with 0.1% chitosan followed by treatment with 5kGy, 10kGy, 20kGy and 50kGy gamma radiation. The infrared spectrum of wool specimens were analyzed by Fourier Transform Infrared Spectrometer (FT-IR). It was found that the infrared spectrum of untreated and treated wool specimens were approximately same except the peak absorb at 1340-1265 cm-1 which indicate the C-N stretch absorption of aromatic amines. After dyeing k/s value of untreated and treated wool specimens were measured using Data color 600 ® .There was a remarkable variation of k/s value on different treatment process. Dye uptake% of untreated and treated wool specimens were determined by using UV Visible Spectrophotometer in terms of absorbency. Color fastness to wash was measured using ISO standard. There was no significant change of wash fastness property of treated and untreated wool.

Surface modification of wool with protease extracted polypeptides

Polypeptides were extracted from wool protein fibres using the serine type protease Esperase 8.0L (EC 3.4.21.62), a subtilisin from Bacillus sp., in a reducing solution. The extracted polypeptides, in aqueous liquor, were then applied to modify the fibre surface of wool fabric with or without additional protease. The treated wool fabric was subsequently treated with the cross-linking agent, glycerol diglycidyl ether, and then underwent a curing process to affix the polypeptide to the fibre. The resulting knitted fabric showed a very high level of shrink-resistance to machine washing, without excessive fibre damage. Shrinkage of 1-2% could be achieved after 5 times 5A washes with minimal (<1%) weight loss due to washing and a burst strength of 317 kPa.

Studies on antibacterial dressings obtained by fluorinated post-discharge plasma

Surface modification of wool, polyamide 6 and cotton fabrics was investigated with an Ar–CF 4 post-discharge plasma. The radical F, as determined by optical emission spectroscopy, is considered to be the main active species acting on the fabrics and producing different effects as a function of the textile substrate. Fluorination of the surface is achieved on the three materials studied, but only wool and polyamide 6 fluorinated surfaces become hydrophobic at long treatment times, and show antibacterial properties. The treatment conditions used are mild enough so as not to alter surface topography, as confirmed by scanning electron and atomic force microscopy.

XPS analysis of down stream plasma treated wool: Influence of the nature of the gas on the surface modification of wool

A microwave plasma treatment in a down stream configuration was used to modify the natural hydrophobocity of untreated wool fibers. This property is a consequence of the presence of a Fatty acid monolayer (F-layer) on the outermost part of the fiber surface. The wool fibers treated with plasma were analyzed by means of X-ray photoelectron spectroscopy (XPS) without previous exposure to the air. Experiments have been carried out with air, water vapor, oxygen and nitrogen as plasma gas. The “in situ” analysis of the treated samples has permitted to differentiate between the plasma effects and those other linked to the exposure of the fibers to the air after their treatment. The results have evidenced the effects induced by the different active species generated by plasma from the different components of the air. In general, the intensity of C C peaks decreases and that of the C O, C O and O C O increases when using a gas containing oxygen species. Simultaneously, the intensity of the S S groups decreases and that of the sulphonate (SO 3 −) increases. Other changes are also detected in the intensity of the N 1s level. The extent and characteristics of the oxidation and functionalisation of the hydrocarbon chains of the F-layer depend on the nature of gas. Thus, whereas treatments with plasmas of air and water vapor strongly affect the hydrocarbon chains of the F-layer, oxygen is less effective in the oxidation process. It has been also noted that the active species formed in the nitrogen plasma do not induce any significant change in the surface composition of the wool fibers.

Surface Modification of Wool and Other Fibrous Materials by 4-Vinylpyridine and Zinc Chloride1

Wool, cotton, polyester, and leather were durably modified by 4-vinylpyridine and zinc chloride applied in acetone. The pendant pyridine rings of the surface deposit, probably poly (4-vinylpyridine), may be free or coordinated through nitrogen with zinc, which may also be bonded to the substrate. Treated wool fabrics resist shrinkage when laundered.