Wettability and Other Surface Properties of Modified Polymers

Abstract

Surface wettability is one of the crucial characteristics for determining of a material's use in specific application. Determination of wettability is based on the measurement of the material surface contact angle. Contact angle is the main parameter that characterizes the drop shape on the solid surface and is also one of the directly measurable properties of the phase interface. In this chapter, the wettability and its related properties of pristine and modified polymer foils will be described. The wettability depends on surface roughness and chemical composition. Changes of these parameters can adjust the values of contact angle and, therefore, wettability. In the case of pristine polymer materials, their wettability is unsuitable for a wide range of applications (such as tissue engineering, printing, and coating). Polymer surfaces can easily be modified by, e.g., plasma discharge, whereas the bulk properties remain unchanged. This modification leads to oxidation of the treated layer and creation of new chemical groups that mainly contain oxygen. Immediately after plasma treatment, the values of the contact angles of the modified polymer significantly decrease.In the case of a specific polymer, the strongly hydrophilic surface is created and leads to total spreading of the water drop. Wettability is strongly dependent on time from modification.Wettability plays a key role, e.g., in the development of biomaterials in tissue engineering and regenerative medicine. Biocompatibility tests of the cell adhesion, proliferation and viability are performed in an aqueous medium, and it is necessary to control the surface wettability. Various cell types have different requirements on surface properties, but while maintaining suitable parameters, the optimal value of © 2015 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.water contact angle for cell adhesion is in the interval of 50-70°. In the case of polymers, which have usually higher values of contact angles, the decrease in water contact angle and adjustment of the surface may be accomplished by introducing selected chemical groups (by plasma treatment), chemical compounds (by grafting, i.e., chemical bath deposition), or nanoparticles. In the case of grafting of polyethylene glycol (PEG) on the plasma activated high-density polyethylene was under "properly" selected conditions of modification (molecular weight of PEG, concentration of PEG in solution) prepared layers that positively influenced the cell adhesion. In addition, low concentration of gold nanoparticles increased the number of adhered cells without decreasing cell viability.Whether the surface of the polymeric substrate is attractive for the adhesion and proliferation of cells is determined not only by wettability but also by a range of other surface properties...

Long-Term Evaluation of Dip-Coated PCL-Blend-PEG Coatings in Simulated Conditions

“…In fact, numerous literature reports have already established the direct connection between the overall enhancement in hydrophilicity of a coating and the addition of PEG in PEG-based composites, as also discussed by Fu et al in [45]. It is known that the surface adsorption of water molecules occurs immediately after the insertion of an implantable material or device inside a biological medium [46]. Secondly, the interaction…”

“…It is known that the surface adsorption of water molecules occurs immediately after the insertion of an implantable material or device inside a biological medium [46]. Secondly, the interaction between the implant and the host organism relies on the surface absorption of the physiological proteins [46].…”

“…It is known that the surface adsorption of water molecules occurs immediately after the insertion of an implantable material or device inside a biological medium [46]. Secondly, the interaction between the implant and the host organism relies on the surface absorption of the physiological proteins [46]. Furthermore, materials with moderately hydrophilic surfaces facilitate the adhesion and subsequent cell growth, ultimately leading to superior biocompatibility [46][47][48][49].…”

“…Secondly, the interaction between the implant and the host organism relies on the surface absorption of the physiological proteins [46]. Furthermore, materials with moderately hydrophilic surfaces facilitate the adhesion and subsequent cell growth, ultimately leading to superior biocompatibility [46][47][48][49]. Figure 5 illustrates the hydrophilic behavior of our obtained blend coatings.…”

Implantação de Íons de Nitrogênio em PMMA Através de uma Fonte Kaufman

“…Dentre elas, destacam-se as aplicações médicas, biomédicas e industriais [2,3]. A modificação de superfície de materiais poliméricos é fundamental para alcançar melhores propriedades mecânicas, tribológicas e morfológicas [4][5][6]. Técnicas com a irradiação iônica, para aumento da dureza [7] e imersão em plasma de baixa potência a fim de melhoria nas propriedades ópticas [8] aplicadas ao PMMA são exemplos de recentes aplicações da engenharia de superfícies ao material.…”