Abstract/Details

Adhesion of patterned polymer interfaces


2007 2007

Other formats: Order a copy

Abstract (summary)

Nature has demonstrated that a powerful strategy for tuning adhesion lies in the development of patterns at an interface. Inspired by the amazing attachment abilities of geckos, we demonstrate that similar design approaches can tune the adhesion of polymer interfaces. In this research, we investigate the role of patterned surfaces in the control of polymer adhesion. Specifically, we demonstrate that patterned surfaces control adhesion by enhancement of the total contact line, or perimeter of the interface, as opposed to increasing the total contact area. This insight is very powerful as it provides new strategies for designing patterned adhesives.

To demonstrate that the pattern control of adhesion is associated with the enhancement in contact line, we explore two unique types of patterned interfaces and their control in adhesion. First, we begin our investigation of patterned adhesion (Chapter 2) by understanding how surface-chemical patterns - i.e. a pattern of periodic variation in surface chemistry, can tune the adhesion of a commercial silicone elastomer. This type of patterned adhesive is unique as almost all previous patterned adhesives are based on topographic patterns. We find a surface-chemical pattern can enhance the adhesion of the elastomer and significant increases are observed for specific pattern geometries. More importantly, the mechanism of enhancement is linked to the changes in the contact line which is controlled by the periodic variation in surface chemistry.

Our results on the adhesion of surface-chemical patterns open new opportunities for developing alternative patterned interfaces for adhesion control. Since the mechanism of control is associated with the enhancement in contact line, we explore an alternative patterning strategy without the use of lithography. In Chapter 3, we explore the concept of surface wrinkling to pattern polymers. We use a combination of osmotic stress, coupled with lateral confinement to generate wrinkles on polymer surfaces. We show control of both the orientation and the length-scale the wrinkle patterns. The wrinkles form as a result of the development of a compressive stress within the polymer film due to the balance between osmotic stress and lateral confinement. There are two main contributions from this work. First, we demonstrate the control of the degree of lateral confinement determines the wrinkling morphology. More importantly, this control leads to the discovery of two new wrinkling morphologies that have not been observed previously. Second, our approach provides direct applications of these structured materials as functional devices. Specifically, we illustrate that our wrinkled polymers can directly be used as an optical array or patterned adhesive (Chapter 4).

In Chapter 4, we combine the lessons learned in the adhesion of surface-chemical patterns (Chapter 2) along with the patterning approach based on surface wrinkling (Chapter 3) to generate a “self-patterned” wrinkled “smart” adhesive. We demonstrate that the adhesive properties are connected with the wavelength of the surfaces wrinkles. With the understanding of the mechanism of contact line enhancement, wrinkled patterns are developed that enhance adhesion by increasing the total contact line during separation. Based on the mechanism of contact line splitting, we develop a scaling relationship that explains how the contact line enhancement is controlled by the wavelength of the wrinkles.

Indexing (details)


Subject
Plastics
Classification
0795: Plastics
Identifier / keyword
Applied sciences; Patterned adhesion; Polymer interfaces; Surface wrinkling
Title
Adhesion of patterned polymer interfaces
Author
Chan, Edwin Pak-Nin
Number of pages
201
Publication year
2007
Degree date
2007
School code
0118
Source
DAI-B 68/11, Dissertation Abstracts International
Place of publication
Ann Arbor
Country of publication
United States
ISBN
9780549330202
Advisor
Crosby, Alfred
Committee member
McCarthy, Thomas; Menon, Narayanan
University/institution
University of Massachusetts Amherst
Department
Polymer Science & Engineering
University location
United States -- Massachusetts
Degree
Ph.D.
Source type
Dissertations & Theses
Language
English
Document type
Dissertation/Thesis
Dissertation/thesis number
3289211
ProQuest document ID
304845764
Copyright
Database copyright ProQuest LLC; ProQuest does not claim copyright in the individual underlying works.
Document URL
http://search.proquest.com/docview/304845764
Access the complete full text

You can get the full text of this document if it is part of your institution's ProQuest subscription.

Try one of the following:

  • Connect to ProQuest through your library network and search for the document from there.
  • Request the document from your library.
  • Go to the ProQuest login page and enter a ProQuest or My Research username / password.