Fabrication of Smart Intercalated Polymer - SMA Nanocomposite

dc.contributor.advisorNicholls, J. R.
dc.contributor.advisorRao, Jeff
dc.contributor.authorAnjum, Sadaf Saad
dc.date.accessioned2015-09-02T18:10:06Z
dc.date.available2015-09-02T18:10:06Z
dc.date.issued2015-03-16
dc.description.abstractMimicking nature gives rise to many important facets of biomaterials. This study is inspired by nature and reports on the fabrication of an intercalated polymer-NiTi nanocomposite that mimics the structural order of urethral tissue performing micturition. PTFE is chosen due to its hydrophobicity, low surface energy, and thermal and chemical stability. NiTi has been selected as a prime candidate for this research due to its excellent mechanical stability, corrosion resistance, energy absorbance, shape memory and biocompatibility. Nanoscale engineering of intercalated nanocomposites is done by PVD sputtering PTFE and NiTi. FTIR spectroscopy confirms that PTFE reforms as polymer chains after sputtering. Suitable PVD sputtering parameters were selected by investigating their influence on deposition rates, microstructure and properties of PTFE and NiTi thin films. PTFE forms stable nanocomposite coatings with NiTi and displays favourable surface interactions, known as ‘intercalation’. Intercalated PTFE-NiTi films were fabricated as layered and co-sputtered thin films. Co-sputtered nanocomposites contained nearly one-third vacant sites within its internal microstructure because of intercalation while intercalation introduced minute pits in fibrous NiTi columns of layered nanocomposites. These pits allow PTFE to extend their chains and crosslinks, resulting in microstructural and functional changes in the thin films. Intercalated PTFE-NiTi nanocomposites offer a close match to the natural tissue in terms of responding to the fluid contact (wetting angle modifications), and allow the soft and hard matter to incorporate in one framework without any chemical reactions (intercalation). An intercalated microstructure in co-sputtered and layered nanocomposites was verified by EDS-SEM and EDS-TEM techniques. The functional responses were witnessed by changes in water contact angle (WCA) and coefficient of friction (CoF) values measured on the film surface. The WCA (99°) and CoF (0.1 – 0.2) of the intercalated nanocomposite (sample PNT12) were different to the NiTi (top layer). WCA and CoF indicate the internal microstructural interactions because of intercalation.Although the pseudoelastic behaviour of NiTi can provide additional fluid response but the difficulty is an absence of crystallinity in as-deposited NiTi, and the heat treatment that melts PTFE. However, DSC and XRD techniques were employed to find the optimum NiTi composition and transition temperatures for phase transformation related to pseudoelasticity. This study provides the basis to incorporate the shape memory (pseudoelasticity or thermal shape memory effect (shape memory effect)) features of NiTi into the intercalated nanocomposite in future. The intercalated PTFE-NiTi nanocomposite reveals a fascinating research precinct, having the response generating characteristics similar to that of natural tissue.en_UK
dc.identifier.urihttp://dspace.lib.cranfield.ac.uk/handle/1826/9384
dc.language.isoenen_UK
dc.publisherCranfield Universityen_UK
dc.rights© Cranfield University 2014. All rights reserved. No part of this publication may be reproduced without the written permission of the copyright owner.en_UK
dc.subjectIntercalated nanocompositeen_UK
dc.subjectintercalated thin filmsen_UK
dc.subjectPVD magnetron sputteringen_UK
dc.subjectthin filmsen_UK
dc.subjectnanocompositesen_UK
dc.subjectnanomaterialen_UK
dc.subjectPTFE-NiTien_UK
dc.subjectPVD-NiTien_UK
dc.subjectPVD-PTFEen_UK
dc.subjectPVD manufacturing parametersen_UK
dc.titleFabrication of Smart Intercalated Polymer - SMA Nanocompositeen_UK
dc.typeThesis or dissertationen_UK
dc.type.qualificationlevelDoctoralen_UK
dc.type.qualificationnamePhDen_UK

Files

Original bundle
Now showing 1 - 1 of 1
Loading...
Thumbnail Image
Name:
Anjum_Sadaf_Saad_Thesis_2015.pdf
Size:
15.86 MB
Format:
Adobe Portable Document Format
License bundle
Now showing 1 - 1 of 1
No Thumbnail Available
Name:
license.txt
Size:
1.79 KB
Format:
Item-specific license agreed upon to submission
Description: