Presentation Title

Controlled Synthesis of Tungsten Trioxide Nanofibers for Gas Sensing

Start Date

November 2016

End Date

November 2016

Location

HUB 302-#151

Type of Presentation

Poster

Abstract

WO3 is abundantly useful in sensor devices due to its characteristic n-type semiconducting ability and its high sensitivity towards a variety of gases. One-dimensional tungsten trioxide structures have been recently investigated as possible sensing media due to excellent response and recovery time. 1D materials are desirable due to their increased electron transport and high surface area to volume ratios. These 1D structures, composite tungsten trioxide nanofibers, were synthesized utilizing the cost-effective and scalable electrospinning method with the incorporation of sol-gel chemistry. The tungsten precursor employed was tungsten isopropoxide. Solution parameters such as surface tension, viscosity, and electrical conductivity and electrospinning parameters such as needle distance to the collector, volumetric flow rate, and applied voltage were controlled to study their effects on the surface morphology and diameter of the as-spun composite nanofibers. The electrospinning process took place within a controlled environment to study the impact that temperature and humidity had on fiber morphology and diameter. Two Taylor cone studies were conducted, firstly by controlling a variable voltage and secondly by varying voltage as well as the volumetric flow rate. These studies were done to observe the effect that a changing electrical field and volumetric flow rate had on the formation and stability of the Taylor cone during the spinning process. From the observed trends, an optimal set of solution, electrospinning, and environmental parameters were determined that yielded as-spun composite tungsten trioxide nanofibers of 79 ± 19 nm diameters and bead density of 0.015 bead/µm2.

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Nov 12th, 4:00 PM Nov 12th, 5:00 PM

Controlled Synthesis of Tungsten Trioxide Nanofibers for Gas Sensing

HUB 302-#151

WO3 is abundantly useful in sensor devices due to its characteristic n-type semiconducting ability and its high sensitivity towards a variety of gases. One-dimensional tungsten trioxide structures have been recently investigated as possible sensing media due to excellent response and recovery time. 1D materials are desirable due to their increased electron transport and high surface area to volume ratios. These 1D structures, composite tungsten trioxide nanofibers, were synthesized utilizing the cost-effective and scalable electrospinning method with the incorporation of sol-gel chemistry. The tungsten precursor employed was tungsten isopropoxide. Solution parameters such as surface tension, viscosity, and electrical conductivity and electrospinning parameters such as needle distance to the collector, volumetric flow rate, and applied voltage were controlled to study their effects on the surface morphology and diameter of the as-spun composite nanofibers. The electrospinning process took place within a controlled environment to study the impact that temperature and humidity had on fiber morphology and diameter. Two Taylor cone studies were conducted, firstly by controlling a variable voltage and secondly by varying voltage as well as the volumetric flow rate. These studies were done to observe the effect that a changing electrical field and volumetric flow rate had on the formation and stability of the Taylor cone during the spinning process. From the observed trends, an optimal set of solution, electrospinning, and environmental parameters were determined that yielded as-spun composite tungsten trioxide nanofibers of 79 ± 19 nm diameters and bead density of 0.015 bead/µm2.