03/30/2026
By Danielle Fretwell

The Francis College of Engineering, Department of Plastics Engineering, invites you to attend a Master's Thesis defense by Jainam Shah on: "Surface Engineering of Nylon 6,6 fabrics for Durable Antimicrobial Characteristics."

Candidate Name: Jainam Shah
Degree: Master’s
Defense Date: Tuesday, April 7, 2026
Time: 3 - 5 p.m.
Location: Southwick 240

Committee:

  • Advisor: Ramaswamy Nagarajan, Distinguished University Professor, Plastics Engineering, Co-Director of HEROES
  • Ramaswamy Nagarajan, Distinguished University Professor, Plastics Engineering, Co-Director of HEROES
  • Amir Ameli, Associate Professor, Plastics Engineering, UMass Lowell
  • Jayant Kumar, Professor, Physics, UMass Lowell
  • Ravi Mosurkal, Co-Director of HEROES

Brief Abstract:
Nylon 6,6 is widely used in textile and technical applications due to its high strength, durability, and ease of processability. However, the chemically stable surface of nylon limits its interaction with other materials, making it challenging for surface functionalization that is launder durable. Therefore, developing durable surface modification strategies for nylon is an important research objective. This research effort presents a simple and effective approach for producing durable antimicrobial nylon 6,6 fabrics through the immobilization of a naturally derived antimicrobial agent, ε-poly-L-lysine (EPL). A two-step approach was implemented to introduce long-lasting antimicrobial functionality. In the first step (Chapter 2), silane coupling agents were employed to modify the nylon surface and enhance its ability to react with functional molecules. Several silane systems were evaluated for their interaction with nylon 6,6. Among them, GPTMS-treated nylon exhibited excellent stability, showing almost no leaching of silane groups from the fabric surface even after 25 accelerated laundering cycles. In the second step (Chapter 3), GPTMS-modified nylon was used to further functionalize EPL (through the reaction between the amine groups of EPL and the epoxy groups of GPTMS). Processing conditions were optimized to achieve strong EPL grafting while maintaining the softness and flexibility of the fabric.

This approach offers several advantages, including: (i) amplification of surface reactivity of Nylon through attachment of functional moieties that can be functionalized subsequently (ii) offers reasonably durable surface coatings with improved stability even after laundering (iii) the modification process is compatible with existing textile processing methods. The treated fabrics demonstrated good antibacterial activity against Staphylococcus epidermidis and Escherichia coli, with bacterial reductions of 96.6% and 93.4%, respectively. Importantly, the fabrics retained antimicrobial performance even after 25 accelerated laundering cycles (AATCC-61), showing reductions of 92.8% against S. epidermidis and 78.4% against E. coli. This study demonstrates that silane-mediated surface functionalization provides a robust and scalable approach for producing durable antimicrobial nylon fabrics. By enabling stable immobilization of antimicrobial molecules on chemically inert polyamide fibers, this work highlights the potential of silane-based strategies for developing advanced functional textiles with long-lasting functional performance.