Martín-Alfonso M A, Rubio-Valle José F, Estrada-Villegas Gethzemani M, Sánchez-Domínguez Margarita, Martín-Alfonso José E
Chemical Product and Process Technology Research Center (Pro2TecS), Department of Chemical Engineering and Materials Science, University of Huelva, 21071 Huelva, Spain.
CONACYT-Centro de Investigación en Química Aplicada, Parque de Innovación e Investigación Tecnológica (PIIT), Apodaca 66628, Mexico.
Gels. 2024 Mar 25;10(4):221. doi: 10.3390/gels10040221.
Developing gelled environmentally friendly dispersions in oil media is a hot topic for many applications. This study aimed to investigate the production of electrospun cellulose triacetate (CTA) nanofibers and to explore their potential application as a thickening agent for castor oil. The key factors in the electrospinning process, including the intrinsic properties of CTA solutions in methylene chloride (DCM)/ethanol (EtOH), such us the shear viscosity, surface tension, and electrical conductivity, were systematically studied. The impact of the CTA fiber concentration and the ratio of DCM/EtOH on the rheological properties of the gel-like dispersions in castor oil was then investigated. It was found that dispersions with a non-Newtonian response and above a critical concentration (5 wt.%), corresponding to approximately 2-2.5 times the entanglement concentration, are required to produce defect-free nanofibers. The average fiber diameter increased with CTA concentration. Further, the morphology and texture of the electrospun nanofibers are influenced by the ratio of solvents used. The rheological properties of dispersions are strongly influenced by the concentration and surface properties of nanofibers, such as their smooth or porous textures, which allow their modulation. Compared to other commonly used thickeners, such as synthetic polymers and metal soaps, CTA electrospun nanofibers have a much higher oil structuring capacity. This work illustrated the potential of using CTA nanofibers as the foundation for fabricating gel-like dispersions in oil media, and thus exerting hierarchical control of rheological properties through the use of a nanoscale fabrication technique.
在油介质中开发凝胶状环保分散体是许多应用领域的热门话题。本研究旨在研究电纺三醋酸纤维素（CTA）纳米纤维的制备，并探索其作为蓖麻油增稠剂的潜在应用。系统研究了静电纺丝过程中的关键因素，包括CTA在二氯甲烷（DCM）/乙醇（EtOH）溶液中的固有性质，如剪切粘度、表面张力和电导率。然后研究了CTA纤维浓度和DCM/EtOH比例对蓖麻油中凝胶状分散体流变性能的影响。结果发现，要制备无缺陷的纳米纤维，需要具有非牛顿响应且高于临界浓度（5 wt.%）的分散体，该临界浓度约为缠结浓度的2-2.5倍。平均纤维直径随CTA浓度的增加而增大。此外，电纺纳米纤维的形态和质地受所用溶剂比例的影响。分散体的流变性能受纳米纤维的浓度和表面性质（如光滑或多孔质地）的强烈影响，这些性质使其能够被调节。与其他常用增稠剂（如合成聚合物和金属皂）相比，CTA电纺纳米纤维具有更高的油结构化能力。这项工作展示了使用CTA纳米纤维作为在油介质中制备凝胶状分散体的基础，并通过使用纳米级制造技术对流变性能进行分级控制的潜力。
