Date of Award
2025
Degree Type
Thesis
Degree Name
Master of Science in Chemical Engineering (MSChE)
Department
Chemical Engineering
First Advisor
Daniel Roxbury
Abstract
Single-walled carbon nanotubes (SWCNTs) are promising optical biosensors due to the sensitivity and photostability of their near-infrared (NIR) fluorescence. In addition to their well-established use in biomarker detection, SWCNT fluorescence responds to mechanical strain, enabling their application in non-contact (optical) strain sensing platforms. Wearable, stretchable strain sensors are of particular interest to researchers due to their seamless interaction with the human body for applications such as healthcare monitoring and human motion detection. While traditional strain sensors often require physical contact and wiring, SWCNT-based optical strain sensors provide a non-contact, real-time alternative with high stability, sensitivity and flexibility.
This thesis presents the development and comprehensive characterization of SWCNT-integrated PVA (Polyvinvyl alcohol)/PAN (Polyacrylonitrile) electrospun textiles with demonstrated mechano-optical sensitivity, enabling non-contact strain sensing. To stabilize the SWCNT dispersion within the core polymer, the PVA solution was systematically optimized with sodium deoxycholate (SDC), identifying 0.02% SDC as the optimal concentration for maintaining long-term colloidal stability without adversely affecting the polymer solution’s properties. Hyperspectral near-infrared (NIR) imaging and fluorescence analysis confirmed successful SWCNT encapsulation within aligned, fluorescent electrospun microfibers, while confocal Raman microscopy verified the presence and approximate spatial localization of SWCNTS, PVA, and PAN within the fibers. Structural, thermal, and chemical characterization via scanning electron microscopy (SEM), differential scanning calorimetry (DSC), Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD), further confirmed successful fiber formation, polymer composition, and a semi-crystalline morphology, respectively.
Performance testing demonstrated the textile’s hydrophilic nature and effective moisture transport capabilities, as shown through contact angle measurements, AATCC Moisture Management Testing (MMT), and vertical capillary testing. Mechanical and mechano-optical testing revealed strain-dependent optical response, with clear center wavelength shifts under tensile load, demonstrating the achieved mechano-optical sensitivity of the textile. Comparisons between dry and Phosphate Buffered Saline (PBS) soaked samples showed that dry textiles exhibited higher Young’s moduli and greater optical responsiveness, indicating environmental conditions influence both mechanical and sensing performance.
This work establishes a foundation for SWCNT-embedded PVA/PAN electrospun textiles for mechano-optical strain sensing and supports their potential for future integration into real-world applications, while motivating continued refinement to improve durability and resilience
Recommended Citation
Schneider, Melissa, "DEVELOPMENT OF OPTICAL STRAIN SENSING “SMART TEXTILE” FOR NON-CONTACT MONITORING OF STRAIN" (2025). Open Access Master's Theses. Paper 2642.
https://digitalcommons.uri.edu/theses/2642