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.

摘要

尽管羊毛具有优异的织物性能, 但其低吸收能力阻碍了其在纺织工业和材料领域的有效应用。表面改性是改善其固有性能的有效途径之一。然而, 表面改性对羊毛的吸收性能的影响尚不清楚。在此, 采用低共熔溶剂法对羊毛表面进行改性。包括化学键, 表面形貌和吸附能力在内的几种物理化学性质被分析。FTIR表明表面改性过程保留了角蛋白的分子结构, 并只断裂了二硫键。FTIR光谱的二次导数谱图进一步表明二级结构也被保留。SEM和EDS分析表明改性过程刻蚀了羊毛表面的鳞片层。总之, 这些变化提高了羊毛的吸收能力。BET测试进一步表明表面改性增加了羊毛的孔洞尺寸, 这有利于吸附能力的提高。对低温下的扩散系数, 吸附等温线, 吸附动力学和热力学参数的进一步分析表明, 表面改性导致了Langmuir到Freundlich模型和伪一级模型到伪二级模型的转变, 并且羊毛的吸附量, 吸附速率和吸附扩散系数随羊毛的熵和焓的降低而增大。

KEYWORDS:

• Wool
• surface modification
• accelerating mechanism
• kinetics
• thermodynamics
• adsorption isotherm

Acknowledgments

The authors thanks for the support from the International Joint Research Laboratory for Eco-Textile Technology at Jiangnan University.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was financially supported by the National Natural Science Foundation of China [51673087]; National Key R&D Program of China [2017YFB0309200]; Postgraduate Research & Practice Innovation Program of Jiangsu Province [KYCX20_1784].