acase@tulane.edu / This work embraces the fabrication of functional materials through the interactions at interfaces and covers two topics.
First, we investigate the assembly of hydrophobically modified polypeptoids (HMPs) with lipid bilayers and the structural transition of lipid bilayers induced by HMPs. Polypeptoids are a class of pseudo-peptidic polymers. Properties such as biocompatibility, biodegradability, enzymatic resistance, and good processibility make polypeptoid a promising material for biotechnological applications. With decyl groups as hydrophobic side chains, HMPs interact with lipid bilayers by inserting the hydrophobes into the lipid bilayers through hydrophobic interaction. The hydrophobe insertion results in the disruption of lipid bilayers and the formation of lipid bilayer fragments containing HMPs and HMP-lipid complexes depending on HMP-to-lipid ratio. These polymer-lipid “rafts” can attach to the bare lipid bilayers forming close-spaced multilamellar structures, with HMPs connecting across the adjacent lipid bilayers. Also, HMP-lipid rafts can significantly increase the solubility of sorafenib in aqueous solution through hydrophobic interaction. The ability to assemble to lipid bilayers and to encapsulate hydrophobic drugs demonstrate the promise of HMP-lipid rafts in the application of drug delivery.
The second topic is the rapid fabrication of hollow and yolk-shell functional materials through an aerosol assisted synthesis. Materials with hollow and yolk-shell structures have potentials in many applications, such as catalysis and energy storage. But the fabrication of such materials often suffers time-consuming and tedious procedures, which limits the practical application of these materials. We first demonstrated the rapid fabrication of hollow and yolk-shell Fe2O3 microspheres for enhanced photo-Fenton reactions. The placement of iron salts on the external surface of a carbonaceous microsphere generated from an aerosol droplet allows the formation of a Fe2O3 capsule by calcination, where colloid particles can be encapsulated. The Fe2O3 microspheres show significant enhancement in the photo-Fenton reaction. We then illustrated the fabrication of hollow and cage-like mesoporous Fe2O3/SiO2 microspheres. Through salt bridge effect, iron salts and cationic surfactants form colloidal aggregates which are locked within a rapidly formed SiO2 shell during the aerosol process. Sucrose as a pore generating agent leads to the formation of mesopores in the shell, which was proven favored features for CO2 capture. / 1 / Yueheng Zhang
| Identifer | oai:union.ndltd.org:TULANE/oai:http://digitallibrary.tulane.edu/:tulane_77506 |
| Date | January 2017 |
| Contributors | Zhang, Yueheng (author), John, Vijay (Thesis advisor), School of Science & Engineering Chemical and Biomolecular Engineering (Degree granting institution) |
| Publisher | Tulane University |
| Source Sets | Tulane University |
| Language | English |
| Detected Language | English |
| Type | Text |
| Format | electronic, 209 |
| Rights | 12 months, Copyright is in accordance with U.S. Copyright law. |
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