Fabrication of Superhydrophobic Cellulose Surfaces via Plasma Processing

Balu, Balamurali

Title:

Fabrication of Superhydrophobic Cellulose Surfaces via Plasma Processing

dc.contributor.author	Balu, Balamurali
dc.contributor.corporatename	Georgia Institute of Technology. School of Chemical and Biomolecular Engineering
dc.contributor.corporatename	Georgia Institute of Technology. Institute of Paper Science and Technology
dc.date.accessioned	2009-01-26T20:58:44Z
dc.date.available	2009-01-26T20:58:44Z
dc.date.issued	2008-10-22
dc.description	2008 Ziegler Award Winner, presented as a keynote address at the 2008 School of Chemical and Biomolecular Engineering Fourth Year Colloquium, Wednesday October 22, 2008.
dc.description	Runtime: 27:53 minutes
dc.description.abstract	In 1805, Young proposed a relationship between the forces acting at an interface between a liquid and solid: “…for each combination of a solid and a fluid, there is an appropriate angle of contact between the surfaces of the fluid, exposed to the air, and to the solid…” However, most real substrates exhibit a variety of contact angles, depending on whether the liquid-air interface is advancing or receding on the solid surface, rather than a unique contact angle. The range of contact angles, usually defined as the difference between the maximum and minimum contact angles observed at the advancing and receding fronts of the liquid drop, is termed contact angle (CA) hysteresis. For classifying the interaction between substrates and liquids, it is critical to specify both the CA and CA hysteresis values. As will be shown in this presentation, even if a surface is superhydrophobic (according to the common definition of a static or advancing water CA > 150°), it can be strongly adhesive to water drops. Contact angle hysteresis most closely correlates with the magnitude of these adhesive forces and by tuning the hysteresis, the dynamics of drops on superhydrophobic surfaces can be controlled, making possible numerous new applications. Superhydrophobicity has been achieved on cellulose surfaces by domain selective etching of amorphous portions of the cellulose, followed by coating of the surface structures generated with a fluorocarbon film deposited via plasma enhanced chemical vapor deposition (PECVD). The hysteresis of these superhydrophobic surfaces can be tuned between 149.8±5.8° and 3.5±1.1° through the controlled fabrication of nano-scale features on the cellulose fibers. This process takes advantage of the inherent nano-meter length scales of the amorphous and crystalline domains of cellulose fibers and the non-conformal film deposition property of PECVD process. Superhydrophobic cellulosic surfaces with tunable hysteresis (adhesion) provide control of aqueous drop mobility and thus of the transfer characteristics of water drops. Moreover, the fact that these substrates are based on cellulose fibers, a biodegradable, inexpensive, flexible, biopolymer, widens potential commercial opportunities for these materials.
dc.format.extent	27:53 minutes
dc.identifier.uri	http://hdl.handle.net/1853/26723
dc.language.iso	en_US	en
dc.publisher	Georgia Institute of Technology	en
dc.relation.ispartofseries	School of Chemical and Biomolecular Engineering Seminar Series	en_US
dc.relation.ispartofseries	School of Chemical and Biomolecular Engineering Seminar Series
dc.subject	Superhydrophobic paper
dc.subject	Cellulose
dc.subject	Water repellant
dc.subject	Plasma
dc.title	Fabrication of Superhydrophobic Cellulose Surfaces via Plasma Processing	en
dc.type	Moving Image
dc.type.genre	Lecture
dspace.entity.type	Publication
local.contributor.corporatename	School of Chemical and Biomolecular Engineering
local.contributor.corporatename	College of Engineering
local.relation.ispartofseries	School of Chemical and Biomolecular Engineering Seminar Series
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relation.isOrgUnitOfPublication	7c022d60-21d5-497c-b552-95e489a06569
relation.isSeriesOfPublication	388050f3-0f40-4192-9168-e4b7de4367b4