Surface Wetting Characteristics of Rubbed Polyimide Thin Films

Zheng, Wenjun

doi:10.5772/8403

Cited by 11 publications

(7 citation statements)

References 36 publications

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“…The surface free energy ( γ S ) of a solid (expressed in mJ·m −2 ) is closely related to its wettability. γ S can be referred to as the excess energy at the surface of a material, compared to that in the bulk [ 30 ]. Every system strives for the lowest possible state of free energy.…”

Section: Methodsmentioning

confidence: 99%

Influence of Surface Corona Discharge Process on Functional and Antioxidant Properties of Bio-Active Coating Applied onto PLA Films

et al. 2023

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PLA (polylactic acid) is one of the three major biopolymers available on the market for food packaging, which is both bio-based and biodegradable. However, its performance as a barrier to gases remains too weak to be used for most types of food, particularly oxygen-sensitive foods. A surface treatment, such as coating, is a potential route for improving the barrier properties and/or providing bioactive properties such as antioxidants. Gelatin-based coating is a biodegradable and food-contact-friendly solution for improving PLA properties. The initial adhesion of gelatin to the film is successful, both over time and during production, however, the coating often delaminates. Corona processing (cold air plasma) is a new tool that requires low energy and no solvents or chemicals. It has been recently applied to the food industry to modify surface properties and has the potential to significantly improve gelatin crosslinking. The effect of this process on the functional properties of the coating, and the integrity of the incorporated active compounds were investigated. Two coatings have been studied, a control fish gelatin-glycerol, and an active one containing gallic acid (GA) as a natural antioxidant. Three powers of the corona process were applied on wet coatings. In the test conditions, there were no improvements in the gelatin crosslinking, but the corona did not cause any structural changes. However, when the corona and gallic acid were combined, the oxygen permeability was significantly reduced, while free radical scavenging, reduction, and chelating properties remained unaffected or slightly improved.

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Section: Methodsmentioning

confidence: 99%

Influence of Surface Corona Discharge Process on Functional and Antioxidant Properties of Bio-Active Coating Applied onto PLA Films

et al. 2023

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“…However, an increase of the substrate surface energy will reach a stage at which the film will spread out and form a film. Further increase in the surface energy of the substrate will result in an easier formation of a film adhesion (21,22). …”

Section: Surface Tensionmentioning

confidence: 99%

Quantitative analysis of povidone-iodine thin films by X-ray photoelectron spectroscopy and their physicochemical properties

Sa¹,

Sawatdee²,

Phadoongsombut

et al. 2017

Acta Pharmaceutica

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In this study, povidone-iodine (PVP-I) has been formulated as a topical spray to produce a thin film for the controlled release of I 2 . By means of experimental design, 27 formulations containing glycerol, ethanol, PEG 400, copovidone and HFA 134a as a propellant were prepared. The pH values of all formulations were in the range of 6-7. The viscosity was within the range of 11.9-85.9 mPa s. The surface tensions were 20.3 to 24.6 mN m -1 and the contact angles were between 19.3 and 38.7°. The assays for the iodine contents were within acceptable range (80-120 %). X-ray photoelectron spectroscopy analysis revealed the ionized form of iodine was much higher than the unionized form. The MIC and MBC values of the PVP-I sprays against Staphylococcus aureus, S. epidermidis and Pseudomonas aeruginosa were higher than that of commercial PVP-I solution. The cytotoxicity study confirmed that the PVP-I spray had lower toxic effects on keratinocytes and fibroblasts compared to the commercial PVP-I solution. The formulation containing 59 % ethanol, 18 % copovidone and 12 % PEG 400 showed good antibacterial activity.Keywords: povidone-iodine, topical spray, bioactivity, cytotoxicity, X-ray photoelectron spectroscopy Human skin harbors many kinds of bacteria, including potential pathogenic bacteria such as Staphylococcus aureus, Streptococcus pyogenes, S. epidermidis, Pseudomonas aeruginosa and even some anaerobic bacteria such as Clostridium spp. that could induce tetanus. These microbes can initiate diseases such as gangrene and dermatitis, when the skin is damaged (1). At procedural and surgical sites, bacteria can create infections that lead to complex

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“…Contaminant-free LIFT requires confinement of chemical changes near the glass-polyimide interface while the polymer surface undergoes a morphological change through blister formation. Since polymers possess lower surface energies (~ 40 mJ/m 2 for polyimide) compared to metals (~ J/m 2 ), we chose a test polymer and carried out studies on chemical composition and morphology [26][27][28]. We used FIB and XPS measurements to study the morphology and chemical composition.…”

Section: Resultsmentioning

confidence: 99%

Surface adhesion of back-illuminated ultrafast laser-treated polymers

Kallepalli

Godfrey

Ratté

et al. 2021

Phys. Rev. Materials

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We report a decreased surface wettability when polymer films on a glass substrate are treated by ultrafast laser pulses in a back-illumination geometry. We propose that back illumination through the substrate confines chemical changes beneath the surface of polymer films, leaving the surface blistered but chemically intact.To confirm this hypothesis, we measure the phase contrast of the polymer when imaged with a focused ion beam. We observe a void at the polymer-quartz interface that results from the expansion of an ultrafast laser-induced plasma. A modified polymer layer surrounds the void, but otherwise the film seems unmodified. We also use x-ray photoelectron spectroscopy to confirm that there is no chemical change to the surface. When patterned with partially overlapping blisters, our polymer surface shows increased hydrophobicity. The increased hydrophobicity of back-illuminated surfaces can only result from the morphological change. This contrasts with the combined chemical and morphological changes of the polymer surface caused by a front-illumination geometry.

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Surface Wetting Characteristics of Rubbed Polyimide Thin Films

Cited by 11 publications

References 36 publications

Influence of Surface Corona Discharge Process on Functional and Antioxidant Properties of Bio-Active Coating Applied onto PLA Films

Influence of Surface Corona Discharge Process on Functional and Antioxidant Properties of Bio-Active Coating Applied onto PLA Films

Quantitative analysis of povidone-iodine thin films by X-ray photoelectron spectroscopy and their physicochemical properties

Surface adhesion of back-illuminated ultrafast laser-treated polymers

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