Preparation of Progressive Antibacterial LDPE Surface via Active Biomolecule Deposition Approach

The use of polymers in all aspects of daily life is increasing considerably, so there is high demand for polymers with specific properties. Polymers with antibacterial properties are highly needed in the food and medical industries. Low-density polyethylene (LDPE) is widely used in various industries, especially in food packaging, because it has suitable mechanical and safety properties. Nevertheless, the hydrophobicity of its surface makes it vulnerable to microbial attack and culturing. To enhance antimicrobial activity, a progressive surface modification of LDPE using the antimicrobial agent grafting process was applied. LDPE was first exposed to nonthermal radio-frequency (RF) plasma treatment to activate its surface. This led to the creation of reactive species on the LDPE surface, resulting in the ability to graft antibacterial agents, such as ascorbic acid (ASA), commonly known as vitamin C. ASA is a well-known antioxidant that is used as a food preservative, is essential to biological systems, and is found to be reactive against a number of microorganisms and bacteria. The antimicrobial effect of grafted LDPE with ASA was tested against two strong kinds of bacteria, namely, Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli), with positive results. Surface analyses were performed thoroughly using contact angle measurements and peel tests to measure the wettability or surface free energy and adhesion properties after each modification step. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to analyze the surface morphology or topography changes of LDPE caused by plasma treatment and ASA grafting. Surface chemistry was studied by measuring the functional groups and elements introduced to the surface after plasma treatment and ASA grafting, using Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). These results showed wettability, adhesion, and roughness changes in the LDPE surface after plasma treatment, as well as after ASA grafting. This is a positive indicator of the ability of ASA to be grafted onto polymeric materials using plasma pretreatment, resulting in enhanced antibacterial activity.

Download Full-text

Functionalization of Neutral Polypropylene by Using Low Pressure Plasma Treatment: Effects on Surface Characteristics and Adhesion Properties

Polymers ◽

10.3390/polym11020202 ◽

2019 ◽

Vol 11 (2) ◽

pp. 202 ◽

Cited By ~ 10

Author(s):

Chiara Mandolfino ◽

Enrico Lertora ◽

Carla Gambaro ◽

Marco Pizzorni

Keyword(s):

Surface Morphology ◽

Photoelectron Spectroscopy ◽

Polymeric Materials ◽

Low Pressure ◽

Contact Angles ◽

Bonded Joints ◽

Water Contact ◽

Adhesion Properties ◽

Pressure Plasma ◽

Low Pressure Plasma

Polyolefins are considered among the most difficult polymeric materials to treat because they have poor adhesive properties and high chemical barrier responses. In this paper, an in-depth study is reported for the low pressure plasma (LPP) treatment of neutral polypropylene to improve adhesion properties. Changes in wettability, chemical species, surface morphology and roughness of the polypropylene surfaces were evaluated by water contact angle measurement, X-ray photoelectron spectroscopy and, furthermore, atomic force microscopy (AFM). Finally, the bonded joints were subjected to tensile tests, in order to evaluate the practical effect of changes in adhesion properties. The results indicate that plasma is an effective treatment for the surface preparation of polypropylene for the creation of bonded joints: contact angles decreased significantly depending on the plasma-parameter setup, surface morphology was also found to vary with plasma power, exposure time and working gas.

Download Full-text

Low-pressure plasma treatment applied to polymeric materials for a sustainable footwear industry

10.24264/icams-2020.iv.19 ◽

2020 ◽

Author(s):

Carlos Ruzafa-Silvestre ◽

Pilar Carbonell-Blasco ◽

Elena Orgiles-Calpena ◽

Francisca Aran Ais

Keyword(s):

Plasma Treatment ◽

Polymeric Materials ◽

Low Pressure ◽

Material Surface ◽

Efficient Technology ◽

Adhesive Properties ◽

Adhesion Properties ◽

Chemical Surface ◽

Pressure Plasma ◽

Low Pressure Plasma

In this paper INESCOP proposes the improvement of the bonding of footwear soling materials using the low-pressure plasma surface treatment as a non-polluting and resource-efficient technology by means of adhesive bonds, with a reactive hot melt polyurethane adhesive, as a more sustainable alternative to current chemical surface treatments such as halogenation. More precisely, low-pressure plasma is capable of cleaning and removing all impurities, such as oxides, oils and fats on material surface. Then, it is activated by producing new chemicals species on the top layer of the substrate. Thus, the materials’ surface acquires new surface functionalities, improving the compatibility adhesive-substrate and, therefore their adhesion properties. Furthermore, in this work the surface modifications produced in these materials of different polymeric nature have been optimised to increase their roughness, wettability, adhesive properties, etc., and have been validated through various experimental characterisation techniques. As a result, the samples treated with plasma meet the adhesion requirements for footwear materials. As a result, low-pressure plasma treatment has desmonstrated to be a green, alternative, and sustainable technology in line with European policies on circular economy, which enhances material surface properties by improving the adhesion bonding process.

Download Full-text

Effects on the Surface and Luminescence Properties of GaAs by SF6 Plasma Passivation

Crystals ◽

10.3390/cryst8090339 ◽

2018 ◽

Vol 8 (9) ◽

pp. 339 ◽

Cited By ~ 2

Author(s):

Yumeng Xu ◽

Xin Gao ◽

Xiaolei Zhang ◽

Zhongliang Qiao ◽

Jing Zhang ◽

...

Keyword(s):

Plasma Treatment ◽

Photoelectron Spectroscopy ◽

Treatment Time ◽

Gaas Surface ◽

Chamber Pressure ◽

Rf Plasma ◽

Force Microscopy ◽

Plasma Passivation ◽

Plasma Treatment Time ◽

The Stability

The passivation effects of the SF6 plasma on a GaAs surface has been investigated by using the radio frequency (RF) plasma method. The RF’s power, chamber pressure, and plasma treatment time are optimized by photoluminescence (PL), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). The PL intensity of passivated GaAs samples is about 1.8 times higher than those which are untreated. The oxide traps and As-As dimers can be removed effectively by using SF6 plasma treatment, and Ga-F can form on the surface of GaAs. It has also been found that the stability of the passivated GaAs surface can be enhanced by depositing SiO2 films onto the GaAs surface. These indicate that the passivation of GaAs surfaces can be achieved by using SF6 plasma treatment.

Download Full-text

Germination of Phaseolus vulgaris L. Seeds after a Short Treatment with a Powerful RF Plasma

International Journal of Molecular Sciences ◽

10.3390/ijms22136672 ◽

2021 ◽

Vol 22 (13) ◽

pp. 6672

Author(s):

Nina Recek ◽

Matej Holc ◽

Alenka Vesel ◽

Rok Zaplotnik ◽

Peter Gselman ◽

...

Keyword(s):

Contact Angle ◽

Phaseolus Vulgaris ◽

Plasma Treatment ◽

Water Contact Angle ◽

Photoelectron Spectroscopy ◽

Rf Plasma ◽

Phaseolus Vulgaris L ◽

Short Treatment ◽

Water Contact ◽

Radicle Growth

Seeds of common bean (Phaseolus vulgaris L.), of the Etna variety, were treated with low-pressure oxygen plasma sustained by an inductively coupled radiofrequency discharge in the H-mode for a few seconds. The high-intensity treatment improved seed health in regard to fungal contamination. Additionally, it increased the wettability of the bean seeds by altering surface chemistry, as established by X-ray photoelectron spectroscopy, and increasing surface roughness, as seen with a scanning electron microscope. The water contact angle at the seed surface dropped to immeasurably low values after a second of plasma treatment. Hydrophobic recovery within a month returned those values to no more than half of the original water contact angle, even for beans treated for the shortest time (0.5 s). Increased wettability resulted in accelerated water uptake. The treatment increased the bean radicle length, which is useful for seedling establishment in the field. These findings confirm that even a brief plasma treatment is a useful technique for the disinfection and stimulation of radicle growth. The technique is scalable to large systems due to the short treatment times.

Download Full-text

Effect of Carbon Black Nanofiller on Adhesion Properties of SBS Rubber Surfaces Treated by Low-Pressure Plasma

Polymers ◽

10.3390/polym12030616 ◽

2020 ◽

Vol 12 (3) ◽

pp. 616

Author(s):

Jacek Tyczkowski ◽

Jacek Balcerzak ◽

Jan Sielski ◽

Iwona Krawczyk-Kłys

Keyword(s):

Carbon Black ◽

Plasma Treatment ◽

Photoelectron Spectroscopy ◽

Peel Test ◽

Low Pressure ◽

Peel Strength ◽

Bonded Joints ◽

Adhesion Properties ◽

Before And After ◽

Adhesive Bonded Joints

Studies on the surface modification of commercial styrene-butadiene-styrene (SBS) rubber with different carbon black (CB) nanofiller content (10–80 parts per hundred parts of rubber (phr)) performed by low-pressure oxygen plasma are presented in this paper. The adhesion properties of the rubber were determined by the peel test for adhesive-bonded joints prepared with a water-based polyurethane (PU) adhesive. The chemical structure and morphology of the SBS rubber surface before and after plasma treatment were investigated by X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM), respectively. The peel tests showed that the plasma treatment significantly improved the strength of adhesive-bonded joints in the entire range of CB tested, revealing a clear maximum for approximately 50 phr of CB. It was also found that as a result of plasma treatment, functional groups that are responsible for the reactions with the PU adhesive, such as C−OH and C=O, were formed, and their concentration, similar to the peel strength, showed maximum values for approximately 50 phr CB. The occurrence of these maxima was explained using the bound rubber model.

Download Full-text

Significant Enhancement of the Adhesion Properties of Chemically Functionalized Polypropylene

Science of Advanced Materials ◽

10.1166/sam.2019.3679 ◽

2019 ◽

Vol 11 (12) ◽

pp. 1699-1704 ◽

Cited By ~ 1

Author(s):

Byoungsang Lee ◽

Jun Hyuk Heo ◽

Jin Woong Lee ◽

Hui Hun Cho ◽

Jung Heon Lee

Keyword(s):

Photoelectron Spectroscopy ◽

Polymeric Materials ◽

Diglycidyl Ether ◽

Chemical Crosslinking ◽

Organosilicon Compounds ◽

Adhesion Properties ◽

X Ray ◽

Epoxy Adhesives ◽

Amine Functionalized ◽

Bisphenol A Diglycidyl Ether

Organosilicon compounds have been actively used with nano- and micro-fillers to improve the adhesion and mechanical properties. However, studies on the adhesion properties of polymeric materials, such as polypropylene (PP), functionalized with organosilicon compounds are limited. Here, we investigated the adhesion of organosilanized PP substrates, functionalized using (3-glycidoxypropyl)trimethoxysilane (GPTMS) and (3-aminopropyl)trimethoxysilane (APTMS) as coupling agents, with epoxy adhesives. The curing of epoxy-functionalized PP (PP-EPOXY) with triethylenetetramine (TETA) hardener led to the chemical crosslinking of TETA with PP-EPOXY, as determined by X-ray photoelectron spectroscopy and vacuum Fourier-transform infrared spectroscopy. Similarly, the curing of amine-functionalized PP (PP-NH2) with bisphenol A diglycidyl ether (DGEBA) epoxy resin led to the chemical crosslinking of the resin with PP-NH2. Finally, we measured the adhesion properties of the functionalized PP substrates using an adhesive composed of DGEBA and TETA based on ASTM D3163 and observed that the shear strength of PP-EPOXY and PP-NH2 increased significantly up to 580% and 506% as compared with that of bare PP. These results strongly suggest that the functionalization of PP significantly contributes to the improvement of adhesion with an adhesive.

Download Full-text

Ammonia RF-Plasma on PTFE Surfaces: Quantification of the Species Created on the Surface by Vapor - Phase Chemical Derivatization

MRS Proceedings ◽

10.1557/proc-662-mm1.7 ◽

2000 ◽

Vol 662 ◽

Author(s):

Chevallier P. ◽

Castonguay M. ◽

Mantovani D. ◽

Laroche G.

Keyword(s):

Plasma Treatment ◽

Vapor Phase ◽

Photoelectron Spectroscopy ◽

Polymer Surface ◽

Chemical Species ◽

Direct Determination ◽

Internal Surface ◽

Rf Plasma ◽

Chemical Derivatization ◽

Phase Chemical

AbstractA cylindrically-configured plasma treatment system in Radio Frequency Glow Discharges fed with ammonia was used with the aim of modifying the internal surface of ePTFE arterial prostheses to improve their biocompatibility. In order to understand the effects of this treatment on the PTFE polymer surface, we have first realized RF-plasma treatment experiments on PTFE films. Preliminary XPS analyses have shown that about 15% of the surface atoms were substituted by nitrogen (N/C ratio of 0.3) whereas the F/C ratio decreased from 2 to 0.6, therefore leading to the conclusion that several chemical species are created onto the surface upon an ammonia plasma treatment. As X-Ray Photoelectron Spectroscopy (XPS) analysis does not allow the direct determination of the nature of the N-species grafted on the surface (chemical shifts are not different enough), vapor phase chemical derivatization was carried out on PTFE films to quantify the concentration of these new surface moities grafted on the polymer surface.

Download Full-text

Preparation Of Moisture Resistant Polylmide Films By Plasma Treatment

MRS Proceedings ◽

10.1557/proc-227-323 ◽

1991 ◽

Vol 227 ◽

Author(s):

Mark A. Petrich ◽

Hsueh Yi Lu

Keyword(s):

Plasma Treatment ◽

Photoelectron Spectroscopy ◽

Polymeric Materials ◽

Moisture Resistance ◽

Polyimide Films ◽

Water Contact ◽

Angle Measurements ◽

Materials Used ◽

Microelectronics Fabrication ◽

Processing Techniques

ABSTRACTPolyimides are an important class of polymeric materials used in microelectronics fabrication. These polymers could be used even more extensively if it were possible to improve their moisture resistance. We are using plasma processing techniques to modify the moisture resistance of polyimide films. Films are exposed to nitrogen trifluoride plasmas to introduce fluorine into the surface of the polyimide. Fluorination is monitored with x-ray photoelectron spectroscopy and Fourier transform infrared absorption spectroscopy. Water contact angle measurements are used to assess the hydrophobicity of the treated surfaces. Thus far, we have demonstrated that this plasma treatment is a good way of introducing fluorine into the polyimide surface, and that these treatments do enhance the hydrophobic nature of polyimide.

Download Full-text

Surface modification of polyimide fibers by oxygen plasma treatment and interfacial adhesion behavior of a polyimide fiber/epoxy composite

Science and Engineering of Composite Materials ◽

10.1515/secm-2015-0092 ◽

2017 ◽

Vol 24 (4) ◽

pp. 477-484 ◽

Cited By ~ 9

Author(s):

Xuyang Sun ◽

Junfeng Bu ◽

Weiwei Liu ◽

Hongqing Niu ◽

Shengli Qi ◽

...

Keyword(s):

Free Energy ◽

Plasma Treatment ◽

Surface Free Energy ◽

Photoelectron Spectroscopy ◽

Interfacial Adhesion ◽

Oxygen Plasma ◽

Dynamic Contact Angle ◽

Epoxy Composites ◽

Oxygen Plasma Treatment ◽

Adhesion Properties

AbstractOxygen plasma was used to enhance the surface behavior of polyimide (PI) fibers and PI fiber-reinforced epoxy composites were prepared in our present work. The effects of plasma treating times on the surface properties of PI fiber and the interfacial adhesion of PI fiber/epoxy composites were investigated. Surface chemical composition, surface morphologies and surface free energy of the fibers were characterized by X-ray photoelectron spectroscopy, scanning electron microscopy and dynamic contact angle analysis, respectively. The results suggest that some oxygen functional groups were introduced onto PI fiber surfaces, and the surface roughness of fibers was enhanced. Resultantly, the surface free energy of fibers and the interfacial adhesion of composites were improved by the oxygen plasma treatment. The interlaminar shear strength of the composites increased to 70 MPa when the fibers were treated for 10 min, which proved good interfacial adhesion properties.

Download Full-text

Enhancement of Adhesion Characteristics of Low-Density Polyethylene Using Atmospheric Plasma Initiated-Grafting of Polyethylene Glycol

Polymers ◽

10.3390/polym13081309 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1309

Author(s):

Taghreed Abdulhameed Al-Gunaid ◽

Igor Krupa ◽

Mabrouk Ouederni ◽

Senthil Kumar Krishnamoorthy ◽

Anton Popelka

Keyword(s):

Polyethylene Glycol ◽

Photoelectron Spectroscopy ◽

Food Packaging ◽

Atmospheric Plasma ◽

Low Density Polyethylene ◽

Limiting Factor ◽

Low Density ◽

Force Microscopy ◽

Angle Measurements ◽

Peel Tests

The low-density polyethylene/aluminum (LDPE/Al) joint in Tetra Pak provides stability and strength to food packaging, ensures protection against outside moisture, and maintains the nutritional values and flavors of food without the need for additives in the food products. However, a poor adhesion of LDPE to Al, due to its non-polar surface, is a limiting factor and extra polymeric interlayers or surface treatment is required. Plasma-assisted grafting of the LDPE surface with different molecular weight compounds of polyethylene glycol (PEG) was used to improve LDPE/Al adhesion. It was found that this surface modification contributed to significantly improve the wettability of the LDPE surface, as was confirmed by contact angle measurements. The chemical composition changes after plasma treatment and modification process were observed by X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). A surface morphology was analyzed by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Adhesion characteristics of LDPE/Al adhesive joints were analyzed by the peel tests. The most significant adhesion improvement of the PEG modified LDPE surface was achieved using 10.0 wt.% aqueous (6000 M) PEG solution, while the peel resistance increased by approximately 54 times in comparison with untreated LDPE.

Download Full-text