References of "Reyes, Catherine 50003616"
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See detailAdvancing flexible volatile compound sensors using liquid crystals encapsulated in polymer fibers
Reyes, Catherine UL; Lagerwall, Jan UL

in Proceedings of SPIE : The International Society for Optical Engineering (2018, February 08), 10555(105550O),

Until recently, organic vapor sensors using liquid crystals (LCs) have employed rigid glass substrates for confining the LC, and bulky equipment for vapor detection. Previously, we demonstrated that ... [more ▼]

Until recently, organic vapor sensors using liquid crystals (LCs) have employed rigid glass substrates for confining the LC, and bulky equipment for vapor detection. Previously, we demonstrated that coaxially electrospinning nematic LC within the core of polymer fibers provides an alternative and improved form factor for confinement. This enables ppm level sensitivity to harmful industrial organics, such as toluene, while giving the flexibility of textile-like sheets (imparted by polymer encapsulation). Moreover, toluene vapor responses of the [less ▲]

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See detailLiquid crystals in micron-scale droplets, shells and fibers
Urbanski, Martin UL; Reyes, Catherine UL; Noh, Junghyun UL et al

in Journal of Physics : Condensed Matter (2017), 29

The extraordinary responsiveness and large diversity of self-assembled structures of liquid crystals are well documented and they have been extensively used in devices like displays. For long, this ... [more ▼]

The extraordinary responsiveness and large diversity of self-assembled structures of liquid crystals are well documented and they have been extensively used in devices like displays. For long, this application route strongly influenced academic research, which frequently focused on the performance of liquid crystals in display-like geometries, typically between flat, rigid substrates of glass or similar solids. Today a new trend is clearly visible, where liquid crystals confined within curved, often soft and flexible, interfaces are in focus. Innovation in microfluidic technology has opened for high-throughput production of liquid crystal droplets or shells with exquisite monodispersity, and modern characterization methods allow detailed analysis of complex director arrangements. The introduction of electrospinning in liquid crystal research has enabled encapsulation in optically transparent polymeric cylinders with very small radius, allowing studies of confinement effects that were not easily accessible before. It also opened the prospect of functionalizing textile fibers with liquid crystals in the core, triggering activities that target wearable devices with true textile form factor for seamless integration in clothing. Together, these developments have brought issues center stage that might previously have been considered esoteric, like the interaction of topological defects on spherical surfaces, saddle-splay curvature-induced spontaneous chiral symmetry breaking, or the non-trivial shape changes of curved liquid crystal elastomers with non-uniform director fields that undergo a phase transition to an isotropic state. The new research thrusts are motivated equally by the intriguing soft matter physics showcased by liquid crystals in these unconventional geometries, and by the many novel application opportunities that arise when we can reproducibly manufacture these systems on a commercial scale. This review attempts to summarize the current understanding of liquid crystals in spherical and cylindrical geometry, the state of the art of producing such samples, as well as the perspectives for innovative applications that have been put forward. [less ▲]

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See detailMorphological traits essential to electrospun and grafted Nylon-6 nanofiber membranes for capturing submicron simulated exhaled breath aerosols
Reyes, Catherine UL; Frey, Margaret

in Journal of Applied Polymer Science (2017), 134(17), 1-15

As contagious bio-aerosols continue to impact our society, we examine how the morphological traits of large-scale (15 cm x 93 cm), uniformly thick, electrospun Nylon membranes can contribute to the ... [more ▼]

As contagious bio-aerosols continue to impact our society, we examine how the morphological traits of large-scale (15 cm x 93 cm), uniformly thick, electrospun Nylon membranes can contribute to the development of diagnostic, sensor driven face masks for capturing exhaled breath content. In our study, we compare the capture efficiencies of three types of large-scale Nylon-6 nanofiber membranes against those of commercial control textiles for capturing in-lab simulated salt breath aerosols. One of the electrospun membranes was also surface functionalized via grafting technique. The fabrication, functionalization, and exhaled aerosol capture of these large-scale membranes underscores the importance of assessing the lifetime, and usability, of electrospun materials before future integration with diagnostic sensing platforms can be successfully achieved. [less ▲]

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See detailNon-electronic gas sensors from electrospun mats of liquid crystal core fibers for detecting volatile organic compounds at room temperature
Reyes, Catherine UL; Sharma, Anshul UL; Lagerwall, Jan UL

in Liquid Crystals (2016)

Non-woven mats comprised of liquid crystal-functionalised fibres are coaxially electrospun to create soft gas sensors that function non-electronically, thus requiring no power supply, detect- ing organic ... [more ▼]

Non-woven mats comprised of liquid crystal-functionalised fibres are coaxially electrospun to create soft gas sensors that function non-electronically, thus requiring no power supply, detect- ing organic vapours at room temperature. The fibres consist of a poly(vinylpyrrolidone) (PVP) sheath surrounding a core of nematic 4-cyano-4ʹpentylbiphenyl (5CB) liquid crystal. Several types of mats, containing uniformly cylindrical or irregular beaded fibres, in uniform or random orientations, are exposed to toluene vapour as a representative volatile organic compound. Between crossed polarisers all mats respond with a fast (response time on the order of a second or faster) reduction in brightness during gas exposure, and they return to the original state upon removal of the gas almost as quickly. With beaded fibres, the response of the mats is visible even without polarisers. We discuss how variations in fibre spinning conditions such as humidity level and the ratio of core-sheath fluid flow rates can be used to tune fibre morphology and thereby the response. Considering future development perspectives, we argue that fibres turned respon- sive through the incorporation of a liquid crystal core show promise as a new generation of sensors with textile form factor, ideal for wearable technology applications. [less ▲]

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See detailDeveloping composite nanofibre fabrics using electrospinning, ultrasonic sewing, and laser cutting technologies
Trejo, Nidia; Reyes, Catherine UL; Sanchez, Vanessa et al

in International Journal of Fashion Design, Technology and Education (2016), 9(3), 192-200

In this study, we combine Nylon 6 nanomembranes with tulle and organza fashion fabrics to construct a full-scale, flying kite. For the first time, this work demonstrates the processing of electrospun ... [more ▼]

In this study, we combine Nylon 6 nanomembranes with tulle and organza fashion fabrics to construct a full-scale, flying kite. For the first time, this work demonstrates the processing of electrospun nanofabrics using laser cut and ultrasonic technologies. The composite fabrics were analysed for their morphological and mechanical properties. The fracture strain of the nanomembrane–tulle composites increased 58–171% compared to the control samples due to nanofibre entanglements on the open weave structure of tulle. The ultrasonic sewn fabric regions endured 169% greater applied stress with the addition of the organza fabric and the seaming process compared to the nanomembrane–tulle composite. [less ▲]

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