Materials Science and Engineering PhD Thesis Defense by Özgün Can Önder

KOÇ UNIVERSITY

GRADUATE SCHOOL OF SCIENCES & ENGINEERING

MATERIALS SCIENCE AND ENGINEERING

PhD THESIS DEFENSE BY ÖZGÜN CAN ÖNDER

Title: Preparation of porous polymeric structures with controlled properties

Speaker: Özgün Can Önder

Time: August 29, 2018, 9:00 AM

Place: ENG B29

Koç University

Rumeli Feneri Yolu

Sariyer, Istanbul

Thesis Committee Members:

Prof. Dr. İskender Yılgör (Advisor, Koç University)

Prof. Dr. Yusuf Ziya Menceloğlu (Sabancı University)

Assoc. Prof. Uğur Ünal (Koç University)

Prof. Dr. Mine Yurtsever (İstanbul Technical University)

Prof. Dr. Burak Erman (Koç University)

Abstract:

In this study, porous polymeric structures were produced with controlled properties by various methods. In the first part of the thesis, poly(lactic acid) and polycaprolactone foams were produced by thermally induced phase separation. Characterization of the foams were achieved by scanning electron microscopy (SEM), x-ray diffractometry (XRD), mercury intrusion porosimetry, infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC). By tuning the process parameters: (i) concentration, (ii) solvent/non-solvent ratio, and (iii) quench temperature, foams with controlled properties such as pore size and shape, porosity, and crystallinity were obtained. In the second part of the thesis, porous poly(lactic acid) coatings were produced by spin coating of solutions under a humid atmosphere. Obtained coatings were characterized by scanning electron microscopy (SEM), white-light interferometry (WLI), and static water contact angle measurements. Properties of the coatings including thickness, pore size and shape, and topography were found to be controlled by: (i) concentration of  the polymer, (ii) magnitude of the humidity in the chamber, (iii) volatility of the solvent, and (iv) thermal conductivity of the substrate.