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- Creators: Barrett, The Honors College
The objective of the experimentation was to explore the effect of crosslinker chain length on the morphology of nanofiber mats. Specifically, poly(vinyl alcohol (PVA) was electrospun into nanofiber mats and poly(ethylene) glycol bis(carboxylic acid) (PEG diacid) was used as the crosslinking agent. As-spun fibers had average fiber diameter of 70 ± 30 nm with an average pore size of 0.10 ± 0.16 μm^2. The fiber diameter for the mats crosslinked with the shorter PEG diacid (Mn = 250) increased to 110 ± 40 nm with an average pore size of 0.11 ± 0.04 μm^2. The mats crosslinked with the longer PEG diacid (Mn = 600) had fiber diameters of 180 ± 10 nm with an average pore size 0.01 ± 0.02 μm^2.
Using DFT calculations and GAMESS computational software, porphine and its derivatives were analyzed for unique sites to accept the adsorbates As(III), As(V) and P(V) in order to compare resulting adsorption energies and determine if any of these molecules prefer arsenic oxyanions over phosphate. Pure porphine preferred As(III) over P(V) with a resulting adsorption energy of -0.7974 eV. Of the functionalized porphyrins tested, carboxyl porphyrin preferred As(V) over P(V) with a total adsorption energy of -0.7345 eV. Ethyl, methyl, chlorine and amino porphyrin all preferred As(III), with energies of -0.7934, -0.8239, -0.7602, and -0.8508 eV, respectively. Of the metalated porphyrins tested, copper and vanadium porphyrin preferred As(V) over P(V) with adsorption energies of -0.7645 and -2.0915 eV. Chromium, iron and magnesium porphyrin all preferred As(III) over P(V) with energies of -0.5993, -1.4539, and - 1.0790 eV, respectively.