Effect of mechanical, barrier and adhesion properties on oxygen plasma surface modified PP

Recent Progress of Biodegradable Polymer Package Materials: Nanotechnology Improving Both Oxygen and Water Vapor Barrier Performance

Biodegradable polymers have become a topic of great scientific and industrial interest due to their environmentally friendly nature. For the benefit of the market economy and environment, biodegradable materials should play a more critical role in packaging materials, which currently account for more than 50% of plastic products. However, various challenges remain for biodegradable polymers for practical packaging applications. Particularly pertaining to the poor oxygen/moisture barrier issues, which greatly limit the application of current biodegradable polymers in food packaging. In this review, various strategies for barrier property improvement are summarized, such as chain architecture and crystallinity tailoring, melt blending, multi-layer co-extrusion, surface coating, and nanotechnology. These strategies have also been considered effective ways for overcoming the poor oxygen or water vapor barrier properties of representative biodegradable polymers in mainstream research.

Experimental Investigation of the Peel Strength of Artificial Leather and Polypropylene Specimens

This study investigates the surface properties and adhesive strength of polypropylene (PP) in order to enhance the bond between PP injection-molded specimens and polyvinyl chloride (PVC) synthetic artificial leather. Plasma, primer, and flame treatments were applied to the surface of each specimen prepared using the two types of injection molds. The surface morphology, surface roughness, and contact angle were analyzed, and peel-strength analyses and a morphological inspections of the peeled specimens were performed. The peeling strength of the PP injection molding was measured, followed by a morphological examination of the peeled specimens. The plasma and flame treatments improved the peel strength, and the plasma and flame treatments changed the rough exterior to a hydrophilic surface, improving the peel strength. In addition, the primer treatment exhibited a lower peel strength than did the other treatments. This confirmed the low adhesion of the primer to the hydrophobic PP surface. The outcomes of this study can be employed across a multitude of industries that require improved adhesion for PP injection molded products.

Improved performance of metal-organic frameworks loaded cellulose acetate based film for packaging application

Bio-nanocomposite-based packaging materials have gained significance due to their possible applications in food packaging. Cellulose acetate is a biopolymer obtained by acetylation of cellulose and has characteristics such as biocompatibility, biodegradability and high transparency. Introducing iron-based metal-organic frameworks offer good mechanical strength, unique surface area and both chemical and thermally stability, making them favourable as supporting materials in fabricating polymer-based packaging materials. Among them, Fe- (Material Institute Lavoisier) MIL-88A is an iron-based nontoxic metal-organic framework, integrated with cellulose acetate and spinach extract was added to the prepared material in different compositions and cast as film. The Spinach loaded, Fe- (Material Institute Lavoisier) MIL-88A integrated cellulose acetate film significantly enhanced the tensile strength, water vapour permeability, and anti-microbial activity. The prepared film is then characterized using a scanning electron microscope (SEM), Fourier transforms infrared spectrometer (FTIR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). Further, studies on mechanical properties as well as degradation tests and real-time applications of the prepared films were carried out.

Electrical Supply Circuit for a Cold Plasma Source at Atmospheric Pressure Based on a Voltage Multiplier

A cold plasma source operating at atmospheric pressure powered by a voltage multiplier is reported. In addition to its usual high voltage output, there is an intermediate output of lower voltage and higher current capability. A discharge current is drawn from both outputs. The ratio of the current supplied by each output depends on the operating state, namely, before or after the plasma jet formation. The electrical circuit is equivalent to two dc sources connected in parallel, used to initiate and sustain the electrical discharge. The plasma source is aimed to study the effect of cold plasma on the surface of various liquid or solid materials, including polymers.

In vivo wound healing efficiency of curcumin-incorporated pectin-chitosan biodegradable films

Curcumin incorporated pectin/chitosan thin films application as a potential wound dressing material with good mechanical, barrier and antibacterial properties.

Application Challenges in Fiber and Textile Electronics

Modern electronic devices are moving toward miniaturization and integration with an emerging focus on wearable electronics. Due to their close contact with the human body, wearable electronics have new requirements including low weight, small size, and flexibility. Conventional 3D and 2D electronic devices fail to efficiently meet these requirements due to their rigidity and bulkiness. Hence, a new family of 1D fiber-shaped electronic devices including energy-harvesting devices, energy-storage devices, light-emitting devices, and sensing devices has risen to the challenge due to their small diameter, lightweight, flexibility, and weavability into soft textile electronics. The application challenges faced by fiber and textile electronics from single fiber-shaped devices to continuously scalable fabrication, to encapsulation and testing, and to application mode exploration, are discussed. The evolutionary trends of fiber and textile electronics are then summarized. Finally, future directions required to boost their commercialization are highlighted.

Preparation and characterization of carrageenan/silver nanoparticles/Laponite nanocomposite coating on oxygen plasma surface modified polypropylene for food packaging

In this work, the nano composites of carrageenan/AgNPs/Laponite were prepared and coated on the oxygen plasma surface modified polypropylene film to enhance the barrier and adhesion properties. The mechanical, barrier, adhesion and antimicrobial properties were also studied to use for food packaging applications. The polypropylene film was surface modified with oxygen plasma treatment for 60 s. The AgNPs are prepared by green synthesis method from the Digitalis purpurea plant. Then the carrageenan based nanocomposites were coated by roller coating method with the thickness of 24 μm. By using scanning electron microscopy, the morphology of the coating was investigated. The Laponite and AgNPs dispersion was analyzed by X-ray diffraction analysis. The tensile and adhesion strength of the coated film was increased and the OTR and WVTR were decreased after the incorporation of Laponite and AgNPs. It exhibited the strong antimicrobial activity against the E. coli and S. aureus.

Polydopamine-Inspired Surface Modification of Polypropylene Hernia Mesh Devices via Cold Oxygen Plasma: Antibacterial and Drug Release Properties

Mesh infection is a major complication of hernia surgery after polypropylene (PP) mesh implantation. Modifying the PP mesh with antibacterial drugs is an effective way to reduce the chance of infection, but the hydrophobic characteristic of PP fibers has obstructed the drug adhesion. Therefore, to prepare antimicrobial PP mesh with a stable drug coating layer and to slow the drug release property during the hernia repair process has a great practical meaning. In this work, PP meshes were coated by bio-inspired polydopamine (PDA), which can load and release levofloxacin. PP meshes were activated with cold oxygen plasma and then plasma activated PP fibers were coated with PDA. The PDA coated meshes were further soaked in levofloxacin. The levofloxacin loaded PP meshes demonstrate excellent antimicrobial properties for 6 days and the drug release has lasted for at least 24 h. Moreover, a control PP mesh sample without plasma treatment was also prepared, after coating with PDA and loading levofloxacin. The antimicrobial property was sustained only for two days. The maximum inhibition zone of PDA coated meshes with and without plasma treatment was 12.5 and 9 mm, respectively. On all accounts, the modification strategy can facilely lead to long-term property of infection prevention.

Modification of Physico-Chemical Properties of Acryl-Coated Polypropylene Foils for Food Packaging by Reactive Particles from Oxygen Plasma

This investigation was focused on the influence of long-living neutral reactive oxygen species on the physico-chemical properties of acryl-coated polypropylene foils for food packaging. Reactive species were formed by passing molecular oxygen through a microwave discharge and leaking it to a processing chamber of a volume of 30 L, which was pumped by a rotary pump. The density of neutral O-atoms in the chamber was tuned by adjustment of both the effective pumping speed and the oxygen leak rate. The O-atom density was measured with a catalytic probe and was between 3 × 10¹⁸ and 5 × 10¹⁹ m⁻³. Commercial foils of biaxially oriented polypropylene (BOPP) coated with acrylic/ poly(vinylidene chloride) (AcPVDC) were mounted in the chamber and treated at room temperature by O atoms at various conditions, with the fluence between 1 × 10²¹ and 3 × 10²⁴ m⁻². The evolution of the surface wettability versus the fluence was determined by water contact angle (WCA) measurements, the formation of functional groups by X-ray photoelectron spectroscopy (XPS), and the morphology by atomic force microscopy (AFM). The WCA dropped from the initial 75° to approximately 40° after the fluence of a few 10²² m⁻² and remained unchanged thereafter, except for fluences above 10²⁴ m⁻², where the WCA dropped to approximately 30°. XPS and AFM results allowed for drawing correlations between the wettability, surface composition, and morphology.