Maximizing contact of supersoft bottlebrush networks with rough surfaces to promote particulate removal

Published

November 12, 2019

Author(s)

Teresa T. Duncan, Edwin P. Chan, Kathryn L. Beers

Abstract

Efficient removal of particulates from a rough surface with a soft material through a ‘press and peel’ method (i.e., an adhesion and release approach) depends on good conformal contact at the interface; a material should be sufficiently soft to maximize contact with a particle while also conforming to rough surface features to clean the entire substrate surface. Here, we investigate the use of bottlebrush networks—extremely soft elastomers composed of macromolecules with polymeric side chains—as materials for cleaning model substrates of varying roughness. Formed through free-radical polymerization of mono- and di-methacrylate functionalized polysiloxanes, these solvent-free supersoft elastomers exhibit moduli comparable to solvated gels, allowing for a lower moduli regime of elastomers to be used in contact experiments. By varying the macromonomer to crosslinker ratio, we studied the effect of modulus on conformal contact and cleaning for materials that are as soft as gels while minimizing/negating physical and/or chemical concerns that using a traditional material may involve (e.g., changes in component concentrations, solvent evaporation, syneresis). We study cleaning efficacy by quantifying the conformal contact between soft materials and rough substrates via a contact adhesion-based measurement. These results give insight into the coupling between material modulus and conformal contact with surfaces of varying feature height. Not only does a decrease in material modulus lead to improved conformal contact with rough surfaces, but it also facilitates adhesion to particulates situated on the rough surface thus aiding removal. We highlight this property control with a case study illustrating the removal of an artificial soil mixture from a rough, acrylic surface via peeling rather than rubbing, which can cause damage to delicate surfaces.

Citation

ACS Applied Materials and Interfaces

Pub Type

Journals

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Keywords

Bottlebrush polymers, elastomers, conformal contact, cleaning, cultural heritage

Citation

Duncan, T. , Chan, E. and Beers, K. (2019), Maximizing contact of supersoft bottlebrush networks with rough surfaces to promote particulate removal, ACS Applied Materials and Interfaces, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=928613 (Accessed April 26, 2024)