scholarly journals WETTING PROPERTIES OF CHITOSAN-MODIFIED AND PLASMA-TREATED PEEK SURFACES

2018 ◽  
Vol XXIII ◽  
pp. 159-169 ◽  
Author(s):  
Kacper Przykaza ◽  
Małgorzata Jurak ◽  
Agnieszka E. Wiącek
Keyword(s):  
Free Energy ◽  
Surface Free Energy ◽  
Contact Angle Hysteresis ◽  
Chitosan Film ◽  
Film Surface ◽  
Contact Angles ◽  
Biologically Active ◽  
Air Plasma ◽  
Wetting Properties ◽  
Total Surface Free Energy

In this paper, the wettability of chitosan/phospholipid (1,2-dipalmitoyl-sn-glycero-3-phosphocholine – DPPC), chitosan/lipid (cholesterol – Chol) and chitosan/protein (cyclosporine A – CsA) films on air plasma activated polyetheretherketone (PEEK) plates was studied. The layers were prepared using the solution spreading technique and their surface wetting properties were determined based on the measurements of the advancing and receding contact angles of water, formamide and diiodomethane. Moreover, based on the contact angle hysteresis model of Chibowski, values of total surface free energy were estimated. Significant changes in PEEK polarity were observed after plasma activation and modifications with Ch/DPPC, Ch/Chol and Ch/CsA layers. These molecules modulate the chitosan film surface by changing the type and magnitude of interactions, which is revealed in the values of surface free energy. These results may be important for the development and implementation of highly biocompatible bone substitution polymers coated with chitosan film with anti-fungal and anti-bactericidal properties. Those systems based on chitosan may also carry and release biologically active substances which could be relevant in the new generation of drug delivery systems.

scholarly journals Wetting Properties of Polyetheretherketone Plasma Activated and Biocoated Surfaces

2019 ◽  
Vol 3 (1) ◽  
pp. 40 ◽  
Author(s):  
Kacper Przykaza ◽  
Klaudia Woźniak ◽  
Małgorzata Jurak ◽  
Agnieszka Wiącek
Keyword(s):  
Contact Angle ◽  
Free Energy ◽  
Surface Free Energy ◽  
Contact Angle Hysteresis ◽  
Biologically Active ◽  
Adhesive Properties ◽  
Surface Sterilization ◽  
Wetting Properties ◽  
Angle Measuring ◽  
Modified Surface

Polyetheretherketone (PEEK) biomaterial is a polymer which has been widely used since the early 90s as a material for human bone implant preparations. Nowadays it is increasingly used due to its high biocompatibility and easily modeling, as well as better mechanical properties and price compared to counterparts made of titanium or platinum alloys. In this paper, air low-temperature and pressure plasma was used to enhance PEEK adhesive properties as well as surface sterilization. On the activated polymeric carrier, biologically-active substances have been deposited with the Langmuir-Blodgett technique. Thereafter, the surface was characterized using optical profilometry, and wettability was examined by contact angle measuring. Next, the contact angle hysteresis (CAH) model was used to calculate the surface free energy of the modified surface of PEEK. The variations of wettability and surface free energy were observed depending on the deposited monolayer type and its components.

scholarly journals Apparent Surface Free Energy of Polymer/Paper Composite Material Treated by Air Plasma

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Konrad Terpiłowski
Keyword(s):  
Surface Roughness ◽  
Free Energy ◽  
Plasma Treatment ◽  
Surface Properties ◽  
Surface Free Energy ◽  
Photoelectron Spectroscopy ◽  
Contact Angles ◽  
Air Plasma ◽  
Surface Plasma ◽  
Composite Surface

Surface plasma treatment consists in changes of surface properties without changing internal properties. In this paper composite polymer/paper material is used for production of packaging in cosmetic industry. There are problems with bonding this material at the time of packaging production due to its properties. Composite surface was treated by air plasma for 1, 10, 20, and 30 s. The advancing and receding contact angles of water, formamide, and diiodomethane were measured using both treated and untreated samples. Apparent surface free energy was estimated using the hysteresis (CAH) and Van Oss, Good, Chaudhury approaches (LWAB). Surface roughness was investigated using optical profilometry and identification of after plasma treatment emerging chemical groups was made by means of the XPS (X-ray photoelectron spectroscopy) technique. After plasma treatment the values of contact angles decreased which is particularly evident for polar liquids. Apparent surface free energy increased compared to that of untreated samples. Changes of energy value are due to the electron-donor parameter of energy. This parameter increases as a result of adding polar groups at the time of surface plasma activation. Changes of surface properties are combination of increase of polar chemical functional groups, increase on the surface, and surface roughness increase.

Simulation-Based Apparent Surface Free-Energy Analysis for Hydrophobic and Superhydrophobic Surfaces

2010 ◽  
Vol 305-306 ◽  
pp. 95-104
Author(s):  
M.Rizwan Malik ◽  
Zi Rong Tang ◽  
Tie Lin Shi ◽  
Shi Yuan Liu
Keyword(s):  
Free Energy ◽  
Surface Free Energy ◽  
High Efficiency ◽  
Field Effect Transistors ◽  
Contact Angles ◽  
Superhydrophobic Surfaces ◽  
Interesting Phenomenon ◽  
Wetting Properties ◽  
Receding Contact ◽  
Free Energy Analysis

Micro/nano outcrops generated on hydrophobic surfaces are vital outcomes of the super-hydrophobic mechanism in the fabrication of miniature batteries, super-capacitors, field effect transistors and electrochemical and biological sensors. In systematized posts positioned on superhydrophobic surfaces, it is critical to alter the contact angle, whilst the retreating one depends upon the post size and spacing. In this paper, it is shown that calculation of the apparent surface free energy concerned with the probe liquid surface tension, and both advancing and receding contact angles (a and r respectively), is useful for bringing special attention to shedding more light on the wetting properties of superhydrophobic surfaces. A simulation is performed, in order to present this interesting phenomenon, which is in reasonable agreement with experiment. It is concluded that the computation supports categorizing the wetting phenomena as well as encouraging further progress in the fabrication of MEMS/NEMS structures with high efficiency, degree of precision, accuracy, uniformity, aspect ratio and through-put.

Bifunctional Composites for Biofilms Modulation on Cervical Restorations

2021 ◽  
pp. 002203452110181
Author(s):  
A.A. Balhaddad ◽  
I.M. Garcia ◽  
L. Mokeem ◽  
M.S. Ibrahim ◽  
F.M. Collares ◽  
...  
Keyword(s):  
Free Energy ◽  
Surface Free Energy ◽  
Contact Angles ◽  
Bacterial Biofilm ◽  
Dental Composite ◽  
Log P ◽  
Rrna Gene ◽  
Cervical Lesions ◽  
Biofilm Growth ◽  
Biofilm Development

Cervical composites treating root carious and noncarious cervical lesions usually extend subgingivally. The subgingival margins of composites present poor plaque control, enhanced biofilm accumulation, and cause gingival irritation. A potential material to restore such lesions should combine agents that interfere with bacterial biofilm development and respond to acidic conditions. Here, we explore the use of new bioresponsive bifunctional dental composites against mature microcosm biofilms derived from subgingival plaque samples. The designed formulations contain 2 bioactive agents: dimethylaminohexadecyl methacrylate (DMAHDM) at 3 to 5 wt.% and 20 wt.% nanosized amorphous calcium phosphate (NACP) in a base resin. Composites with no DMAHDM and NACP were used as controls. The newly formulated 5% DMAHDM–20% NACP composite was analyzed by micro-Raman spectroscopy and transmission electron microscopy. The wettability and surface-free energy were also assessed. The inhibitory effect on the in vitro biofilm growth and the 16S rRNA gene sequencing of survival bacterial colonies derived from the composites were analyzed. Whole-biofilm metabolic activity, polysaccharide production, and live/dead images of the biofilm grown over the composites complement the microbiological assays. Overall, the designed formulations had higher contact angles with water and lower surface-free energy compared to the commercial control. The DMAHDM-NACP composites significantly inhibited the growth of total microorganisms, Porphyromonas gingivalis, Prevotella intermedia/nigrescens, Aggregatibacter actinomycetemcomitans, and Fusobacterium nucleatum by 3 to 5-log ( P < 0.001). For the colony isolates from control composites, the composition was typically dominated by the genera Veillonella, Fusobacterium, Streptococcus, Eikenella, and Leptotrichia, while Fusobacterium and Veillonella dominated the 5% DMAHDM–20% NACP composites. The DMAHDM-NACP composites contributed to over 80% of reduction in metabolic and polysaccharide activity. The suppression effect on plaque biofilms suggested that DMAHDM-NACP composites might be used as a bioactive material for cervical restorations. These results may propose an exciting path to prevent biofilm growth and improve dental composite restorations’ life span.

scholarly journals Surface modification and adhesion improvement of polyester films

2013 ◽  
Vol 11 (1) ◽  
pp. 35-45 ◽  
Author(s):  
Aniello Cammarano ◽  
Giovanna Luca ◽  
Eugenio Amendola
Keyword(s):  
Free Energy ◽  
Surface Modification ◽  
Surface Free Energy ◽  
Self Assembly ◽  
Treatment Time ◽  
Solution Treatment ◽  
Film Surface ◽  
Critical Surface ◽  
Hydrolysis Time ◽  
Critical Surface Tension

AbstractFacile surface modification of polyester films was performed via chemical solutions treatment. Surface hydrolysis was carried out by means of sodium hydroxide solutions, leading to the formation of carboxylate groups. Three commercial polyester films of 100 μm in thickness were used in this work: AryLite™, Mylar™, and Teonex™, hydrolysis time being the main modification parameter. FTIR-ATR analysis, topography and contact angle (CA) measurements, surface free energy (SFE) and T-Peel adhesion tests were carried out to characterize the modified films. A quantitative estimate of the carboxylates surface coverage as a function of treatment time was obtained through a supramolecular approach, i.e. the ionic self-assembly of a tetracationic porphyrin chromophore onto the film surface. The surface free energy and critical surface tension of the hydrolyzed polyesters was evaluated by means of Zisman, Saito, Berthelot and Owens-Wendt methods. It was shown that NaOH solution treatment increases roughness, polarity and surface free energy of polymers. As a result, T-Peel strengths for modified Mylar™ and Teonex™ films were respectively 2.2 and 1.8 times higher than that for the unmodified films, whereas AryLite™ adhesion test failed.

scholarly journals Influence of Light Intensity on Surface Free Energy and Dentin Bond Strength of Core Build-up Resins

2015 ◽  
Vol 40 (1) ◽  
pp. 87-95 ◽  
Author(s):  
Y Shimizu ◽  
A Tsujimoto ◽  
T Furuichi ◽  
T Suzuki ◽  
K Tsubota ◽  
...  
Keyword(s):  
Free Energy ◽  
Light Intensity ◽  
Bond Strength ◽  
Surface Free Energy ◽  
Testing Machine ◽  
Contact Angles ◽  
Significance Level ◽  
The Core ◽  
Light Intensities ◽  
Bond Strengths

SUMMARY Objective We examined the influence of light intensity on surface free energy characteristics and dentin bond strength of dual-cure direct core build-up resin systems. Methods Two commercially available dual-cure direct core build-up resin systems, Clearfil DC Core Automix with Clearfil Bond SE One and UniFil Core EM with Self-Etching Bond, were studied. Bovine mandibular incisors were mounted in acrylic resin and the facial dentin surfaces were wet ground on 600-grit silicon carbide paper. Adhesives were applied to dentin surfaces and cured with light intensities of 0 (no irradiation), 200, 400, and 600 mW/cm2. The surface free energy of the adhesives (five samples per group) was determined by measuring the contact angles of three test liquids placed on the cured adhesives. To determine the strength of the dentin bond, the core build-up resin pastes were condensed into the mold on the adhesive-treated dentin surfaces according to the methods described for the surface free energy measurement. The resin pastes were cured with the same light intensities as those used for the adhesives. Ten specimens per group were stored in water maintained at 37°C for 24 hours, after which they were shear tested at a crosshead speed of 1.0 mm/minute in a universal testing machine. Two-way analysis of variance (ANOVA) and a Tukey-Kramer test were performed, with the significance level set at 0.05. Results The surface free energies of the adhesive-treated dentin surfaces decreased with an increase in the light intensity of the curing unit. Two-way ANOVA revealed that the type of core build-up system and the light intensity significantly influence the bond strength, although there was no significant interaction between the two factors. The highest bond strengths were achieved when the resin pastes were cured with the strongest light intensity for all the core build-up systems. When polymerized with a light intensity of 200 mW/cm2 or less, significantly lower bond strengths were observed. Conclusions The data suggest that the dentin bond strength of core build-up systems are still affected by the light intensity of the curing unit, which is based on the surface free energy of the adhesives. On the basis of the results and limitations of the test conditions used in this study, it appears that a light intensity of &gt;400 mW/cm2 may be required for achieving the optimal dentin bond strength.

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