Synthesis and Study of Engineered Heterogenous Polymer Gels

PDF Version Also Available for Download.

Description

This dissertation studies physical properties and technological applications of engineered heterogenous polymer gels. Such gels are synthesized based on modulation of gel chemical nature in space. The shape memory gels have been developed in this study by using the modulated gel technology. At room temperature, they form a straight line. As the temperature is increased, they spontaneously bend or curl into a predetermined shape such as a letter of the alphabet, a numerical number, a spiral, a square, or a fish. The shape changes are reversible. The heterogenous structures have been also obtained on the gel surface. The central idea ... continued below

Physical Description

xi, 121 leaves : ill.

Creation Information

Chen, Yuanye August 1998.

Context

This dissertation is part of the collection entitled: UNT Theses and Dissertations and was provided by UNT Libraries to Digital Library, a digital repository hosted by the UNT Libraries. It has been viewed 25 times . More information about this dissertation can be viewed below.

Who

People and organizations associated with either the creation of this dissertation or its content.

Author

Publisher

Rights Holder

For guidance see Citations, Rights, Re-Use.

  • Chen, Yuanye

Provided By

UNT Libraries

The UNT Libraries serve the university and community by providing access to physical and online collections, fostering information literacy, supporting academic research, and much, much more.

Contact Us

What

Descriptive information to help identify this dissertation. Follow the links below to find similar items on the Digital Library.

Degree Information

Description

This dissertation studies physical properties and technological applications of engineered heterogenous polymer gels. Such gels are synthesized based on modulation of gel chemical nature in space. The shape memory gels have been developed in this study by using the modulated gel technology. At room temperature, they form a straight line. As the temperature is increased, they spontaneously bend or curl into a predetermined shape such as a letter of the alphabet, a numerical number, a spiral, a square, or a fish. The shape changes are reversible. The heterogenous structures have been also obtained on the gel surface. The central idea is to cover a dehydrated gel surface with a patterned mask, then to sputter-deposit a gold film onto it. After removing the mask, a gold pattern is left on the gel surface. Periodical surface array can serve as gratings to diffract light. The grating constant can be continuously changed by the external environmental stimuli such as temperature and electric field. Several applications of gels with periodic surface arrays as sensors for measuring gel swelling ratio, internal strain under an uniaxial stress, and shear modulus have been demonstrated. The porous NIPA gels have been synthesized by suspension technique. Microstructures of newly synthesized gels are characterized by both SEM and capillary test and are related to their swelling and mechanical properties. The heterogenous porous NIPA gel shrink about 35,000 times faster than its counterpart--the homogeneous NIPA gel. Development of such fast responsive gels can result in sensors and devices applications. A new gel system with built-in anisotropy is studied. This gel system consists of interpenetrated polymer network (IPN) gels of polyacrylamide (PAAM) and N-isopropylacrylamide (NIPA). The swelling property of the anisotropy IPN gels along the pre-stressing direction is different from that along other directions, in contrast to conventional gels which swell isotropically. It is found that the ratio (L/D) of length (L) and diameter (D) of IPN samples has step-wise changes as the samples are heated from below the volume phase transition temperature to the above. A theoretical model is proposed and is in good agreement with the experimental results.

Physical Description

xi, 121 leaves : ill.

Subjects

Keywords

Library of Congress Subject Headings

Language

Identifier

Unique identifying numbers for this dissertation in the Digital Library or other systems.

Collections

This dissertation is part of the following collection of related materials.

UNT Theses and Dissertations

Theses and dissertations represent a wealth of scholarly and artistic content created by masters and doctoral students in the degree-seeking process. Some ETDs in this collection are restricted to use by the UNT community.

What responsibilities do I have when using this dissertation?

When

Dates and time periods associated with this dissertation.

Creation Date

  • August 1998

Added to The UNT Digital Library

  • March 24, 2014, 8:07 p.m.

Description Last Updated

  • Aug. 7, 2014, 11:40 a.m.

Usage Statistics

When was this dissertation last used?

Yesterday: 0
Past 30 days: 0
Total Uses: 25

Interact With This Dissertation

Here are some suggestions for what to do next.

Start Reading

PDF Version Also Available for Download.

International Image Interoperability Framework

IIF Logo

We support the IIIF Presentation API

Chen, Yuanye. Synthesis and Study of Engineered Heterogenous Polymer Gels, dissertation, August 1998; Denton, Texas. (digital.library.unt.edu/ark:/67531/metadc278503/: accessed October 16, 2018), University of North Texas Libraries, Digital Library, digital.library.unt.edu; .