<p>The
functionalization of nonwoven electrospun polymeric fibers with metallic
nanostructures has enabled the design of novel nanocomposite materials used in
a wide range of applications. In particular, designs based on incorporating
established antimicrobial species such as copper and silver have potential
applications as antimicrobial filtration membranes, leveraging on the convoluted
fiber assembly and high surface area–to–volume ratios of the constitutive
fibers. Electroless deposition based on spontaneous electrochemical reactions
offers a facile and tunable methodology for surface–confined growth of metallic
nanostructures on the non–planar substrate architectures presented by nonwoven
electrospun fibers. </p>
<p>Firstly, this
work explores, in a broad sense, the effects of two different seed catalyst
chemistries, palladium and silver, on the evolution of copper nanoparticles on
electrospun polyacrylonitrile fibers. Copper nanoparticle coverage and
conformity; deposition kinetics; modifications in the surface chemistry of the
PAN fibers; and thermal stability of the resultant nanocomposites were
examined. Secondly, qualitative and quantitative assessment of the interfacial
adhesion between the copper nanostructures and PAN fibers were undertaken by
exploiting the elastic mismatch between both phases during tensile deformation.
For copper nanocubes on nanofibers, the adhesion energy is estimated to be
between 0.48 J/m<sup>2</sup> and 1.0 J/m<sup>2</sup> using strain and growth
based adhesion models.</p>
<p>Macroscopically,
the compliant nature of the nonwoven fiber mats makes them susceptible to
out-of-plane deformation during water filtration processes which may alter
their size exclusion configuration for effective filtration. A bulge testing
device is built and implemented to simulate and characterize hydraulic flow –
induced deformation in the electrospun PAN fiber mats. The pressure–deflection
relationships of the mats show a sub-linear dependence in contrast to classical
continuum materials. The macroscopic mat behavior was governed by the
properties of the constituent fibers, with an apparent mat bending rigidity
dependent on the fiber diameters.</p>
<p> Lastly, the nonwoven fiber mats functionalized
with copper nanoparticles were evaluated for use as potential antimicrobial
microfiltration membranes. The fiber mats displayed high water flux and high
separation efficiency for model 3 μm
particles, with separation factors reaching above 99%.</p>
| Identifer | oai:union.ndltd.org:purdue.edu/oai:figshare.com:article/14502798 |
| Date | 29 April 2021 |
| Creators | Temitope Q Aminu (10716801) |
| Source Sets | Purdue University |
| Detected Language | English |
| Type | Text, Thesis |
| Rights | CC BY 4.0 |
| Relation | https://figshare.com/articles/thesis/Templated_Metallic_Nanostructures_on_Electrospun_Fibers_Synthesis_Mechanical_Characterization_and_Filtration_Application/14502798 |
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