Polyethylene with MoS₂ nanoparticles toward antibacterial active packaging

Abstract

Molybdenum disulfide (MoS 2 ) nanoparticles, obtained from liquid phase exfoliation in the presence of chitosan, were melt mixed with a linear low-density polyethylene (LLDPE) matrix to produce novel antimicrobial active packaging materials. The LLDPE/MoS 2 composites presented exfoliated nanoparticles forming aggregates that are well dispersed in the polymer matrix. These 2Dlayered MoS 2 nanoparticles at concentrations of 0.5, 1.0, and 3.0 wt% rendered several functionalities to the LLDPE, as for example an antimicrobial behavior against Salmonella typhi and Listeria monocytogenes bacteria that can be explained not only by the photoactivity of the filler but also by changes in the composite surface. For instance, the composites presented a reduction in the water contact angle (i.e., an increased hydrophilicity) and relevant changes in the surface topography (i.e., reduced roughness) as compared with pure LLDPE. Regarding the barrier properties, while MoS 2 dramatically increased the water vapor permeation (WVP) of the polymer matrix, until 15 times for composite with 3.0 wt% of filler, the oxygen permeation decreased around 25%. All these novel functionalities in the nanocomposites were obtained without significantly affecting the tensile mechanical properties of the pure LLDPE matrix. These results show that MoS 2 is a promising filler for the development of antibacterial active packaging films with behaviors as similar as other 2Dlayered fillers such as graphene derivatives.

Polylactic‐Acid Having MoS2 Particles for Reversible Bilayer Actuators

“…These results confirmed the mechanical reinforcement effect of this nanofiller as reported for similar particles in other matrices. [ 25,26 ] Despite the large increase in the polymer stiffness by the presence of MoS 2 nanoparticles, the elongation at break is drastically reduced in the composites from 40% for the pure PLA to 3.8% for the composite with exfoliated MoS 2 . Melt‐mixed and 3D‐printed samples presented different mechanical behaviors with pure PLA displaying an elastic modulus of 2186 MPa that is more than four times higher than the value from the solvent‐mixed samples.…”

“…From the different fillers available for producing polymer composited actuators, MoS 2 is highlighted as a transition metal dichalcogenide relevant for producing multifunctional nanocomposites. [21][22][23][24][25][26] MoS 2 nanosheets further presented layered structure and outstanding mechanical properties being an ideal filler in polymer matrix toward composites with improved mechanical behavior. [24,26] For instance, a previous study designed a paper bilayer using a 2D metallic 1T-MoS 2 with dualresponse and self-sensing function actuated under external voltage and light stimulation.…”

Polymer Packaging through the Blending of Biowaste Oyster Shell and Low-Density Polyethylene: A Sustainable Approach for Enhanced Food Preservation

“…LDPE was enriched with molybdenum disulfide (MoS 2 ) nanoparticles at varying concentrations of 0.5%, 1%, and 3%, leading to the development of antimicrobial blend packaging materials. Although these materials demonstrated superior antibacterial properties against Salmonella typhi and Listeria monocytogenes, which could be attributed to both the photoactivity of the filler and changes on the blend surface, a diminished barrier performance was observed [7]. Nanoblends were prepared using a wet casting method, incorporating a hydrothermally synthesized lithium-titanate (Li-TiO 2 ) photocatalyst and subsequently combining it with LDPE.…”