Mechanical behavior at nanoscale of chitosan‐coated PE surface

Abstract

Chitosan coating of polyethylene (PE) was proposed as a new procedure to improve its biocompatibility and surface properties. The functionalization of the PE film surface by covalent bonding of chitosan coating and its effect on the surface mechanical properties, as surface elasticity, stiffness, and adhesion (that are important in different biological processes) were investigated by nano-indentation, scratch, and atomic force microscopy. It has been established that chitosan grafting onto corona functionalized PE surface using various coupling agents significantly improves the surface hardness and elastic modulus although they decrease in depth of the layer. Compared to the neat PE substrate, the chitosan coated samples show significant improved friction properties and tear resistance. The surface roughness features correlate with the micro-mechanical parameters. Therefore, the covalent immobilization of the chitosan onto PE leads to a stable coating with better mechanical performance being recommended as a promising material for medical applications and food packaging.

Antioxidant/Antibacterial Electrospun Nanocoatings Applied onto PLA Films

“…Various procedures have been proposed for preparation of the antimicrobial coating: Spreading with a thin-layer chromatography applicator [ 5 ] or a lab bench coater [ 7 ]; using a bar coater [ 15 ] or a brush [ 16 ]; spraying (nebulization) [ 17 ]; lamination [ 18 ]; gravure printing [ 9 ]; dip-coating [ 19 ]; and translated, at industrial scale, by coupling with a wet-coating station and roll-to-roll system [ 20 ].…”

Chitosan’s effects on the acidity, copper ion release, deflection, and surface roughness of copper-nickel-titanium archwire

“…43 On the contrary, it was found that the polyethylene coated with the chitosan nanoparticle exhibited improved frictional properties in the rough surface, which were analyzed with an AFM. 41 From the results obtained in this study using two solutions, Group B (2% chitosan) demonstrated buffer effects in the pH with lower copper ion release, but there was no significant difference in the unloading force. Further investigation is needed to evaluate the effects of 2% chitosan on another chemical element in terms of ion release, deflection simulating orthodontic treatment, and surface roughness using AFM analysis or an SEM mathematical analysis.…”

“…42 Even though the previous study found that the polyethylene coated with the chitosan nanoparticle improved friction due to its rough surface, according to the AFM analysis, the archwire with the chitosan nanoparticle coated in stainless-steel (SS) instead reduced friction, as confirmed by a sliding test carried out with a universal testing machine, and exhibited a smoother surface, according to a subjective analysis of the SEM images. 41,43 The unloading force of CuNiTi archwire decreased from weeks 2 to 4 and increased again from weeks 4 to 6, with both groups exhibiting almost the same force at Week-2. A study was discussed which examined hysteresis or force loss between nickel-titanium (NiTi) and CuNiTi when stored in water, subjected to temperature changes, and in an acidic condition for 60 days, which simulated an orthodontic treatment in the mouth.…”

“…The study was carried out using nano-indentation, a scratch test to the surface, and measured by an atomic force microscope (AFM). 41 The unloading force is also affected by friction, which occurs due to the resistance between the wire and bracket; in this in vitro experiment, the effects of friction were not analyzed. 42 Even though the previous study found that the polyethylene coated with the chitosan nanoparticle improved friction due to its rough surface, according to the AFM analysis, the archwire with the chitosan nanoparticle coated in stainless-steel (SS) instead reduced friction, as confirmed by a sliding test carried out with a universal testing machine, and exhibited a smoother surface, according to a subjective analysis of the SEM images.…”