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Polyimide Aerogels and Their Applications in Removal of Airborne Nanoparticles

Zhai, Chunhao
http://rave.ohiolink.edu/etdc/view?acc_num=akron1464284202

Abstract Details

2016, Master of Science, University of Akron, Polymer Engineering.
Airborne particles are considered extremely hazardous to human health. The hazard level of these particles have an inverse relationship with the size. PM2.5 particles, particulate matter with diameter less than 2.5 µm, can get into human breathing passages to cause general diseases like cough, while even smaller particles with diameter less than 1 µm may go inside the air sacs which may increase the risk of lung cancer. Removal of airborne nanoparticles has become an urgent task in recent years. In first part of this study, the feasibility of using monolithic polyimide aerogels as filter media for removal of airborne nanoparticles in air flow was investigated. Polyimide gels were synthesized from chemical reactions between pyromellitic dianhydride (PMDA), 2,2'-dimethylbenzidine (DMBZ), and 1, 3, 5-triaminophenoxylbenzene (TAB) dissolved in a good solvent. The gels were dried via supercritical drying in CO2 to obtain the aerogels. The porosity of polyimide aerogels was controlled by changing the initial concentration of solids in the solutions from 2.5 wt% to 10 wt%. The resulting aerogels show high porosity(91%-98%), high surface area (473 m2/g-817 m2/g), and low bulk density (0.025 g/cm3-0.12 g/cm3). High values of nanoparticle filtration efficiency (>99.95%) was obtained for those monoliths with high bulk density (>0.05 g/cm3). The measurements showed that air permeability of these aerogels were of the order of 10-10 m2. Carbon dioxide and nitrogen adsorption isotherms were used to determine the fraction of micropores, mesopores, and macropores in total pore volume of these specimens. A strong proportional relationship between the fraction of macropores and the permeability was observed which indicates that the macropores handled air permeability in these aerogel materials, while the mesopores provided high efficiency in nanoparticle filtration. In second part of this study, polyimide aerogel microparticles were produced by conducting sol-gel reactions in an oil-in-oil emulsion system. This emulsion system was created by dispersing in cyclohexane the droplets of polyimide solutions prepared in dimethylformamide. The resultant PI aerogel microparticles showed mean diameter of 40 µm and surface area of 512 m2/g.
Sadhan Jana (Advisor)
Younjin Min (Committee Chair)
Kevin Cavicchi (Committee Member)
82 p.
Polymers
Aerogel; Nanoparticle filtration

Recommended Citations

Citations

  • Zhai, C. (2016). Polyimide Aerogels and Their Applications in Removal of Airborne Nanoparticles [Master's thesis, University of Akron]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=akron1464284202

    APA Style (7th edition)

  • Zhai, Chunhao. Polyimide Aerogels and Their Applications in Removal of Airborne Nanoparticles. 2016. University of Akron, Master's thesis. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=akron1464284202.

    MLA Style (8th edition)

  • Zhai, Chunhao. "Polyimide Aerogels and Their Applications in Removal of Airborne Nanoparticles." Master's thesis, University of Akron, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=akron1464284202

    Chicago Manual of Style (17th edition)

akron1464284202
2,558
© 2016, some rights reserved.Creative Commons License Polyimide Aerogels and Their Applications in Removal of Airborne Nanoparticles by Chunhao Zhai is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License. Based on a work at etd.ohiolink.edu.
This open access ETD is published by University of Akron and OhioLINK.