Type of Document	Dissertation
Author	Hu, Qingchun
URN	etd-10022008-063009
Title	Fabrication and characterization of poly(amide-imides)/TiO{u2082} nanocomposite gas separation membranes
Degree	PhD
Department	Chemical Engineering
Advisory Committee	Advisor Name Title Marand, Eva Committee Chair Davis, Richey M. Committee Member Kander, Ronald G. Committee Member Marand, Hervé L. Committee Member Wilkes, Garth L. Committee Member
Keywords	polymer metal oxide composite sol-gel gas separation membrane
Date of Defense	1996-10-15
Availability	restricted
Abstract Nanosized Ti02 rich domains were generated in-situ within poly(amide-imide) (PAl) and 6F-poly(amide-imide) (6FPAl) by a sol-gel process. The composite films showed a high optical transparency. The morphology of the Ti02 rich domains was observed by transmission electron microscopy (TEM). The Ti02 rich domains were well dispersed within the poly(amide-imide) and 6F-poly(amide-imide) matrices and were 5 nm to 50 nm in size. Limited study was also carried out for the fabrication of the P AI/Si02 and PAI/fi02-Si02 composites. It was found that nanosized Si02 rich domains were difficult to form within the poly(amide-imide) matrix, although the Si02 could be bonded with the Ti02, forming nanosized domains within the poly(amide-imide) matrix. The P AIffi02 composites showed an increased glass transition temperature, and an increased rubbery plateau modulus, in comparison to the unfilled poly(amide-imide). Wide Angle X- ray Diffraction (W AXD) study and Differential Scanning Calorimetry (DSC) analysis suggest that the Ti02 filled poly( amide-imide) have a lower crystallinity as compared to the unfilled poly(amide-imide). The dynamic mechanical properties in rubbery regions suggest that Ti02 domains function as physical crosslinks, increasing the rubbery plateau modulus with increasing Ti02 content. This behavior can be explained by the theory of rubbery elasticity. The actual formation of the nanosized Ti02 and Ti02-Si02 rich domains was explained in terms of hydrogen bonding effects between the polymer, the solvent and the inorganic components.
Files	Filename       Size       Approximate Download Time (Hours:Minutes:Seconds)     28.8 Modem   56K Modem   ISDN (64 Kb)   ISDN (128 Kb)   Higher-speed Access  LD5655.V856_1996.H8.pdf 21.63 Mb 01:40:08 00:51:29 00:45:03 00:22:31 00:01:55 next to an author's name indicates that all files or directories associated with their ETD are accessible from the Virginia Tech campus network only.

If you have questions or technical problems, please Contact DLA.