Surface properties polymers

Chapter 5 shows that the application of hydrolytic enzymes is a powerful yet mild strategy to directly improve polymer surface properties (i.e. hydrophilicity) or activate materials for further processing. The surface hydrolysis of polyamides (PA), polyethyleneterphthalates (PET) and polyacrylonitriles (PAN) is discussed, as well as the mechanistic details on the enzymatic surface hydrolysis. The mechanistic data, combined with advances in structural and molecular biology, help to explain different activities of closely related enzymes on polymer surfaces. 

Part II Case Studies Macromolecules, Polymer Morphology and Polymer Surface Properties by AFM... 

At present, the protein/surface interactions that determine adsorption kinetics are unclear. To clarify these interactions, the effects of polymer surface properties on protein adsorption and desorption rates have been investigated. BSA adsorption from a 1 mg% solution (1 mg% = 1 mg/100 mL) was studied using several polymers chosen for their wide range of surface properties and functionalities (22, Cheng, Y.L. et al.. J. Coll. Int. Sci., in press). The polymers and their surface properties (under the conditions of the BSA adsorption experiments) are listed in Table I. 

In this contribution, we report on the surface modifications of polymers by a dual frequency electron cyclotron resonance (ECR) plasma and their influence on the formation of the metal-polymer interfaces. The surface modifications are studied with respect to different parameters of the plasma treatment including the influence of an atmospheric contact. The interface of an evaporated metal film with a polymer surface is characterized in terms of the observed growth mode of the film as a function of the polymer surface properties. 

Borcia G, Chiper A, Rusu 1. Using a He-FN2 dielectric barrier discharge for the modification of polymer surface properties. Plasma Sources Sci Technol 2006 15 849. 

A logical corrolary to the importance placed on interactions at polymer surfaces and interfaces is the ability to control these interactions through appropriate surface modiflcations. The desirability of controlling polymer surface properties has been evident for many years and various strategies have been developed toward that end. The strategies may be classified in the following, rather general way ... 

For polymer surface properties controlled by the chemical composition, thermodynamic (equihbrium), non-equihbrium, and technical terms and definitions play an important role. These are not always used in a consistent way, hence a short recapitulation seems appropriate. The thermodynamic work of adhesion (Wa) is defined as the reversible work (the free energy change) required to separate two phases with unit area of contact, from contact to infinity. The corresponding work of adhesion (and cohesion for similar bodies) can be easily expressed with surface tension values. In general, for surfaces of two intimately contacting solids ( l and 2 , respectively) each with a unit area, are separated in a medium ( 3 ), a work VT132 is required which can be expressed as ... 

Liu FP, Gardner DJ, Wolcot MP. A model for the description of polymer surface dynamic behavior 1. Contact angle vs polymer surface properties. Langmuir 1995 11 2674—2681. 

Abstract The current chapter gives a general overview on surface-initiated nitroxide-mediated polymerization (SI-NMP). More particularly, the developed strategies to perform an SI-NMP process, the various type of substrates including inorganic and organic supports, and the potential of SI-NMP to prepared advanced materials are discussed. Based on a selected number of literature examples it appears that SI-NMP is a versatile and powerful approach to introduce polymer brushes on surfaces and/or tune polymer surface properties. 

Polymer surface properties control wettability, adhesion, and fnction, and, in some cases, electronic properties. Gas-phase chlorination of polyethylene surfaces is done just for this purpose, and the reaction can be followed using x-ray photoelectron spectroscopy (XPS). The XPS technique can identify various chemical species within 10-70 pm of the surface. In the chlorination of polyethylene, the species are —CH2, —CHC—, —CCI2—, —CH—CH—, and —CH—CX—. Observe that the chlorination proceeds through a radical mechanism. The mechanism of polymerization, assuming that aU reaction steps are reversible, can be represented by... 

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