Influence of ambient humidity on the apparent surface free energy of poly(methyl methacrylate) (PMMA)

2008 ◽  
pp. 103-120
Keyword(s):  
Free Energy ◽  
Methyl Methacrylate ◽  
Surface Free Energy ◽  
Poly Methyl Methacrylate ◽  
Ambient Humidity

scholarly journals Effects of nystatin, fluconazole and propolis on poly(methyl methacrylate) resin surface

2008 ◽  
Vol 19 (3) ◽  
pp. 190-196 ◽  
Author(s):  
Wander José da Silva ◽  
Rodrigo Nunes Rached ◽  
Pedro Luis Rosalen ◽  
Altair Antoninha Del Bel Cury
Keyword(s):  
Free Energy ◽  
Methyl Methacrylate ◽  
Antifungal Agents ◽  
Knoop Hardness ◽  
Deionized Water ◽  
Control Groups ◽  
Denture Base ◽  
Poly Methyl Methacrylate ◽  
Acrylic Resins ◽  
Pmma Surface

The prevalence of candidosis in denture wearers is as well established as its treatment with antifungal agents (AAs). However, little research has been done regarding the effects of AAs on denture base surfaces. Therefore, the aim of this study was to evaluate the effects of fluconazole (FLU), nystatin (NYS) and propolis orabase gel (PRO) on poly (methyl-methacrylate) (PMMA) surfaces. Deionized water and orabase gel without any active component were used as control groups. Conventional heat-polymerized (Clássico) and microwave-polymerized (Onda Cryl) acrylic resins were used. After polymerization, the specimens were polished and had their surfaces evaluated for roughness, free energy and Knoop hardness. Subsequently, specimens were immersed in AAs and controls for 14 days at 35±2 °C and all variables were measured again. Data were analyzed statistically by 2-way ANOVA followed by Tukey's test ( α=0.05). Roughness results showed similar behavior for both PMMA resins, with PRO reaching the highest values and differing significantly from the other AAs (p<0.05). No statistically significant differences (p>0.05) were found between the two PMMA resins or between NYS and FLU as regards surface free energy. In conclusion, PRO was able to induce changes in PMMA surface properties, such as roughness, which could be related to microbial adhesion.

scholarly journals Surface Activation of Poly(Methyl Methacrylate) with Atmospheric Pressure Ar + H2O Plasma

Coatings ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 228 ◽  
Author(s):  
Essam Abdel–Fattah
Keyword(s):  
Contact Angle ◽  
Free Energy ◽  
Methyl Methacrylate ◽  
Surface Treatment ◽  
Plasma Treatment ◽  
Surface Free Energy ◽  
Atmospheric Pressure ◽  
Treatment Time ◽  
Plasma Treatment Time ◽  
Pmma Surface

The atmospheric pressure of Ar + H 2 O plasma jet has been analyzed and its effects on the poly(methyl methacrylate) (PMMA) surface has been investigated. The PMMA surface treatment was performed at a fixed gas flow-rate discharge voltage, while varying the plasma treatment time. The Ar + H 2 O plasma was studied with optical emission spectroscopy (OES). Optimum plasma conditions for PMMA surface treatment were determined from relative intensities of Argon, hydroxyl radical (OH), oxygen (O) I emission spectra. The rotational temperature T rot of Ar + H 2 O plasma was determined from OH emission band. The PMMA surfaces before and after plasma treatment were characterized by contact angle and surface free energy measurements, X-ray photoelectrons spectroscopy (XPS), atomic force microscope (AFM) and UV-spectroscopy. The contact angle decreased and surface free energy increased with plasma treatment time. XPS results revealed the oxygen to carbon ratio (O/C) on plasma-treated PMMA surfaces remarkably increased for short treatment time ≤60 s, beyond which it has weakly dependent on treatment time. The carbon C1s peak deconvoluted into four components: C–C, C–C=O, C–O–C and O–C=O bonds and their percentage ratio vary in accordance with plasma treatment time. AFM showed the PMMA surface roughness increases with plasma treatment time. UV-visible measurements revealed that plasma treatment has no considerable effect on the transparency of PMMA samples.

Smectic A-Smectic B interface : faceting and surface free energy measurement

1989 ◽  
Vol 50 (24) ◽  
pp. 3527-3534 ◽  
Author(s):  
P. Oswald ◽  
F. Melo ◽  
C. Germain
Keyword(s):  
Free Energy ◽  
Surface Free Energy ◽  
Energy Measurement ◽  
Smectic A

Examination of the lubricant storing and releasing ability of thermally sprayed surfaces

2011 ◽  
Vol 2 (2) ◽  
pp. 101-105
Author(s):  
L. Fazekas ◽  
Z. S. Tiba ◽  
G. Kalácska
Keyword(s):  
Free Energy ◽  
Surface Energy ◽  
Surface Free Energy ◽  
Essential Role ◽  
Index Number ◽  
Adhesion Ability ◽  
Thermally Sprayed ◽  
Proper Operation

Abstract The lubricant storing and releasing ability of the thermally sprayed surfaces plays an essential role in the proper operation of the components. In the case of porous sprayed surfaces the lubricant storing and releasing ability depends mainly on porosity and the surface energy (adhesion susceptibility). The adhesion ability can also be expressed indirectly with an index number that is by determining the surface free energy.

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