Nanofiber Filter Performance : Systemic Study on Efficiency, Reusability, Protection and Breathability

• Main Author: Venkataraman, Dhanya
• Format: Dissertation
• Language: English
• Published: ProQuest Dissertations & Theses 01-01-2024
• Subjects: Biomedical engineering; Nanoscience; Polymer chemistry
• ISBN: 9798381449075

The surge in demand for nonwoven personal protective equipment (PPE) fabrics, particularly due to the COVID-19 pandemic, prompts a critical examination of their current state. We explore material composition and production processes, from filament fiber creation using various spinning methods to fiber bonding through chemical, thermal, and mechanical techniques. We also discuss emerging methods like electrospinning and centrifugal spinning to produce nanofibers. Nonwoven PPE finds applications in filters, medical uses, and protective garments, with a focus on understanding each layer's role and textile integration. Challenges arising from the single-use nature of nonwoven PPE, amid growing sustainability concerns, are addressed, along with innovative solutions for reusability. In a comparative study, two methods for producing nanofiber filters, using polylactic acid (PLA), are examined: centrifugal spinning and electrospinning. While both techniques achieve efficient submicron particle filtration, centrifugal spinning PLA filters exhibit a wider diameter distribution within the mat, leading to significantly lower pressure drops (<200 Pa). Centrifugal spun samples’ quality factor surpasses electrospun samples, with remarkable reusability. After ten cycles of treatment, they maintain filtration efficiency ≥95% with a pressure drop (≤270 Pa), conforming to NIOSH N95 standards. In contrast, electrospun samples exhibit higher pressure drops (>343 Pa) after similar treatment. These centrifugal spinning PLA filters perform comparably or better than existing nanofiber-based filters and offer the advantage of reusability, potentially mitigating waste management concerns. Moreover, they are transformed into masks and rigorously evaluated using Schlieren imaging for factors like breathability, comfort, leakage, and heat buildup. Studies comparing various spun types and assessing performance before and after treatment using visualization provide valuable insights on their reusability which presents a promising path towards sustainable PPE solutions.