Silver-Loaded HDPE/Clay Nanocomposites With Antibacterial Property: A Potential Replacement for Commodity Polyethylene Plastic Anasuya Roy, 1 Mangala Joshi , 1 Bhupendra Singh Butola, 1 A.K. Srivastava 2 1 Department of Textile Technology, Indian Institute of Technology Delhi, Delhi 110016, India 2 Gas Authority of India Ltd (GAIL India Ltd), Noida, Uttar Pradesh 201301, India A silver intercalated clay based HDPE nanocomposite with excellent antibacterial activity has been reported for the first time. Antibacterial silver-clay (Ag-MMT) synthesized in laboratory was incorporated into HDPE to prepare antibacterial HDPE/Ag-MMT nanocompo- sites. Silver has been chosen as it is a powerful antimi- crobial agent with additional properties such as unique optical, electrical, and thermal characteristics. The nanocomposites were fabricated through melt mixing route in a twin-screw extruder with varying Ag-MMT concentrations. Transmission electron microscopy, scanning electron microscopy, differential scanning calorimetry, and X-ray diffraction studies confirmed superior dispersion of clay platelets in HDPE. Dynamic oscillatory properties and mechanical characteristics of the nanocomposites were determined to observe the effect of Ag-MMT on HDPE. Antimicrobial testing of these nanocomposites against Gram-negative bac- teria Escherichia coli O157:H7 and Gram-positive bac- teria Staphylococcus aureus showed excellent bioactivity (>99%) at 5 wt% Ag-MMT. These antibacte- rial plastic materials have potential to replace neat HDPE products in niche areas where antimicrobial property would be highly desirable. POLYM. COMPOS., 00:000–000, 2017. V C 2017 Society of Plastics Engineers INTRODUCTION Modern world has laid great importance on wellbeing and health and improved living standards of the current decade demand most articles of daily use to be resistant against harmful microbes. In such times, antimicrobial items have gained profound significance not only in health and medical sectors but also in regular household items. This has paved the way for investigations on anti- microbial materials as a significant research area in scien- tific and technological world [1]. Polyethylene is undeniably one of the most used commodity plastic in contemporary times having a wide spectrum of applica- tions in day-to-day life [2]. However, it does not have any inherent antibacterial activity which if present could improve standards of the products made from high den- sity polyethylene (HDPE) in terms of better hygiene con- ditions. Some applications of antibacterial polyethylene can be readily cited from our everyday life: crates that are used for transportation and storage of fruits, and vege- tables, baby toys, pipes, buckets and mugs, inner linings of washing machines, kitchen dustbins etc. Conventional approaches to prepare antimicrobial polyethylene includes incorporating antimicrobial agents such as N-halamine compounds [3], essential oils of Basil [4], bacteriocin [5], potassium sorbate [6], glass and zinc particles [7], copper ions [8], and polymerized urushiol powders [9]. Since the target application is active packag- ing based on films almost all these approaches have been tried on low density polyethylene (LDPE) and linear low density polyethylene (LLDPE) with none of the papers focusing on HDPE used for molded items and sheets. In the last decade, polymer nanocomposites have emerged as a new class of hybrid materials which have generated much research interest and a great deal of scien- tific literature is presented which discusses its various enhanced property contributions owing to incorporation of a nanofiller in a polymer matrix [10, 11]. Investigations into their fundamental and molecular structure as well as their various characteristic properties reveals their great potential in the development of new materials and systems composed of functionalized organic and inorganic hybrid nanocomposites. The researchers of Toyota Central Research and Development Labs, Japan were the first research group to successfully produce polymer nanocom- posite based on polyamide and clay [12–14]. Its tensile and flexural properties were exceptionally good and since then different polymers have been tried for production of useful polymer nanocomposites. The understanding behind these Correspondence to: M. Joshi; e-mail: mangala@textile.iitd.ac.in Contract grant sponsor: Gas Authority of India Ltd. (GAIL India). DOI 10.1002/pc.24451 Published online in Wiley Online Library (wileyonlinelibrary.com). V C 2017 Society of Plastics Engineers POLYMER COMPOSITES—2017