The combined effect of wrinkles and noncircular shape of fibers on wetting behavior of electrospun cellulose acetate membranes

Abstract

Roughness-induced hydrophobicity is an area of rapid growth which can be achieved through surface texture or surface porosity. Characterizing the effect of surface roughness on wetting behavior of surfaces with irregular shapes has always been a challenging problem. In this work, changing the environmental conditions during electrospinning of hydrophilic cellulose acetate solutions produced highly porous ribbon like fibers, differed widely in their surface morphologies. All samples showed apparent hydrophobicity with water contact angles between 1218 and 1468. The specific surface area was introduced for the first time, as a comprehensive parameter to predict contact angles of noncircular fibers. Statistical modeling revealed that the log-linear models would better fit the data in comparison with the other linear forms. These results confirmed that the specific surface area could be an appropriate single variable for predicting the contact angles of multiscale porous and wrinkled structures of electrospun fibers. Moreover, the membrane produced at 20 8C temperature and the relative humidity of 60% revealed surprisingly high specific surface area (276.63 m 2 /g) that seems very promising for industrial applications such as separation technologies.

Optimization of bacterial nanocellulose fermentation using recycled paper sludge and development of novel composites

“…Images at higher magnifications also provided evidence of the strong interfacial adhesion between BNC nanofibrils and the polymers, as shown by the cross-section images after fracturing and the homogeneous dispersion within the BNC network, individual cellulose fibres being no longer visible. It is well accepted that the water-solid contact angle varies with a combined effect of both surface chemistry and roughness of the surface (Yousefi et al 2018). Thus, although topography may partially justify the increase in contact angle (the higher porosity of BNC may contribute to a lower contact angle), this result is mainly related to the lower surface energy of the hydrophobic compounds impregnated with the composites.…”

A ternary system oleophilic–hydrophobic membrane prepared by electrospinning for efficient gravity-driven oil–water separation

“…Preparation of porous CA has been intensively investigated by electrospinning, which leads to a large specific surface area. [42] As shown in Table 2, the membrane M-0-3/7 possessed the largest specific surface area of 27.620 m 2 /g. Moreover, the pore volume also reaches the maximum, indicating a larger contact area between oil and fiber when oil penetrates into the membranes.…”

“…CA is well recognized as a hydrophilic polymer. Theoretically, expansion of CA concentration increases the number of hydrophilic macromolecules that make up the fiber, but in the context of electrospinning, roughness of fiber surface plays a crucial role in the hydrophobicity of the membrane [42]. PVDF is embroiled in fiber formation as shown in Fig.…”

A Review on the Secondary Surface Morphology of Electrospun Nanofibers: Formation Mechanisms, Characterizations, and Applications

“…Therefore, the generation of fibers with wrinkled surfaces has been a subject of significant interest. The wrinkled structure has been generated successfully from different polymers such as PVDF, PS, poly(lactic acid) (PLA), PMMA, cellulose triacetate, ipp, and ethyl cellulose …”