Highly sticky surfaces made by electrospun polymer nanofibers

TL;DR

This study investigates the exceptional water adhesion properties of electrospun PMMA nanofiber mats, revealing their potential for applications in microfluidics, filtration, and catalytic surfaces due to their unique wetting behavior.

Contribution

It provides a detailed analysis of how fiber orientation and diameter influence water adhesion and wetting properties of electrospun nanofiber surfaces, highlighting their superior adhesion capabilities.

Findings

Nanofiber mats hold water drops more than twice as large as other hairy surfaces.

Aligned fibers exhibit anisotropic wetting behavior with high water volume capacity.

Static contact angle remains around 130°, unaffected by fiber diameter.

Abstract

We report on a comprehensive study of the unique adhesive properties of mats of polymethylmethacrylate (PMMA) nanofibers produced by electrospinning. Fibers are deposited on glass, varying the diameter and the relative orientation of the polymer filaments (random vs aligned configuration). While no significant variation is observed in the static contact angle (about 130{\deg}) of deposited water drops upon changing the average fiber diameter up to the micrometer scale, fibers are found to exhibit unequalled water adhesion. Placed vertically, they can hold up water drops as large as 60 microL, more than twice the values typically obtained with hairy surfaces prepared by different methods. For aligned fibers with anisotropic wetting behavior, the maximum volume measured in the direction perpendicular to the fibers goes up to 90 {\mu}L. This work suggests new routes to tailor the wetting behavior on extended areas by nanofiber coatings, with possible applications in adsorbing and catalytic surfaces, microfluidic devices, and filtration technologies.