Antibacterial effect of boron nitride flakes with controlled orientation in polymer composites

Abstract

Boron nitride (BN) is a stable 2D material with physiochemical properties similar to graphene-based nanomaterials. We have recently demonstrated that vertically aligned coatings of graphene-based nanomaterials provide strong antibacterial effects on various surfaces. Here we investigated whether BN, a nanomaterial with extensive similarities to graphene, might exhibit similar antibacterial properties. To test this, we developed a novel composite material using BN and low density polyethylene (LDPE) polymer. The composite was extruded under controlled melt flow conditions leading to highly structured morphology, with BN oriented in the extrusion flow direction. Nanocomposite extruded surfaces perpendicular to the flow direction were etched, thus exposing BN nanoparticles embedded in the matrix. The antimicrobial activity of extruded samples was evaluated against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus epidermidis and Staphylococcus aureus by the colony forming units (CFUs) counting method. Furthermore, the bactericidal effect of oriented BN against E. coli and S. aureus was evaluated by scanning electron microscopy (SEM) and live/dead viability assay. Our results suggest that BN nanoflakes on the extruded BN/LDPE composite physically interact with the bacterial cellular envelope, leading to irreparable physical damage. Therefore, we propose that BNpolymer composites might be useful to develop polymer based biomedical devices protected against bacterial adhesion, and thus minimize device associated infections.

Mechanical Behavior of Melt-Mixed 3D Hierarchical Graphene/Polypropylene Nanocomposites

“…Over the last 15 years, the performance of high aspect ratio fillers has shown great promise and opened a wide range of opportunities in the area of polymer nanocomposites [ 1 ]. Consequently the use of different fillers of high-aspect ratio has led to the development of high-performance and multifunctional materials with a wide range of industrial applications, for example, as gas-barrier membranes [ 2 , 3 , 4 , 5 ], antibacterial surfaces [ 6 , 7 , 8 ], heat-sinks [ 9 , 10 ] and electronics [ 11 ].…”

A Mechanics Based Surface Image Interpretation Method for Multifunctional Nanocomposites

“…This can enable the creation of highly structured (thermoplastic in this case) polymer nanocomposites [1,18,19]. Such bulk nanocomposite morphologies exhibit anisotropic electrical and thermal properties with potential applications to field grading materials [18] and heat management components [1] as well as antibacterial properties [20]. A basic general performance requirement for nanocomposites is the filler’s mechanical reinforcing effect.…”

“…As alluded to in Figure 1f,g, the nano-structures of the images were embedded 1D elements, cf. in [20], whereas the neat PE resin represents the bulk of the image area. In order to predict the theoretical increase in the stiffness of the overall composite, a finite element model-based method was developed.…”

Few Layered Oxidized h-BN as Nanofiller of Cellulose-Based Paper with Superior Antibacterial Response and Enhanced Mechanical/Thermal Performance

“…Hexagonal boron nitride, which is considered as a structural analogue of graphene [ 12 ], has received an enormous amount of attention in the last few years [ 13 , 14 ], due to its versatile features: excellent thermal and mechanical properties, chemical stability [ 15 ], low density [ 16 ], and biocompatibility [ 17 ], to name few. The latter along with unique mechanical strength allow its application in composite materials [ 18 ] to enhance their properties, especially for the paper-making industry.…”

“…It is understandable to think that its antibacterial potential could be similar to that one of graphene, considering their structural analogy and the resemblance of some features. Despite all these facts, until now, there have been only a few papers on the investigation of boron nitride antimicrobial properties [ 12 ], as well as cellulose and boron nitride composites [ 20 ]. One of the h-BN disadvantages to be even wider explored is lack of water solubility.…”