Graft substrate

In addition, there is the difficulty of controlling the grafted side chains in molecular weight distribution. In the context of this chapter, the authors hope to give a systematic, comprehensive, up-to-date review on the various methods of grafting, the methods used for characterization of grafted substrates, and their possible end use applications. 

Scheme 12 Mode of action of multi-functional acrylates in improving the grafting efficiency, through branching of grafted substrate chains...

A 50 denier rayon monofilament ( 90u diameter), courtesy of American Enka, was used as the grafting substrate. The samples were Soxhlet extracted in methanol prior to use. 

The factors that decisively affected the grafting efficiency in grafting styrene were (a) the activity of the initiator radical (the predominant factor), and (b) the activity of the grafting substrate, i.e. the chemical composition, structure, and crystallinity of the substrate. 

Measurements of Platelet Consumption. A baboon AV shunt model was used to assess quantitatively the effects of physicochemical properties associated with polyacrylamide grafted substrates. In this model, measurements of platelet consumption using 51Cr-labeled platelets were steady state, reproducible between test animals, and unaffected by the surgical procedure (8,10). The methodology involved in the use of AV baboon shunts has been described previously (8,10). We concluded that this primate model simulates arterial thrombotic processes in humans and is suitable for the in vivo evaluation of biomaterial thrombogenesis (10). 

Table III. Platelet Consumption by Polyacrylamide-Grafted Substrates (9)...

Measurements have been made, in the AFM contact mode, of both chemical and mechanical local attractive or adhesive forces of model substrates. Assuming that the main technical uncertainties have been listed and minimized, surface force measurements were first performed on chemically modified silicon substrates (grafted with hydroxyl, amine, methyl, and ester functional groups). The surface chemistry contribution (in particular, its hydrophilic features) is dominant in the measurement of the adhesion force. A linear relationship has been obtained between the van der Waals component of the thermodynamic work of adhesion and the surface energy of the silicon grafted substrates. 

PCL thin films. A preferential orientation dose to the normal direction was detected for PCL crystalline chains, while the PMMA block seemed to be completely isotropic. Moreover, AFM analyses were complementary to PM-IRRAS and offered us the possibility of developing two different models of chain adsorption on the gold and the OH-grafted substrates. 

On the other hand, cells and proteins exhibit space- and time-dependent dynamic changes in their conformations and functionalities in the human body. Since the 1990s, dynamic switchable surfaces have been comprehensively studied in order to control the biomolecular dynamics by modification with smart polymers [6], which show changes in their conformations and properties in response to external stimuli. Among them, thermo-responsive poly(AT-isopropylacrylamide) (PNlPA/ m) is one of the most successful models to control the interaction between biomolecules and the grafted substrates by temperature... 

Preparation of Maleimide- (M) and Peptide- (or L-Cysteine-) Modified (P) Samples. Twenty silanized titaniiun samples (A) were placed in a self-fabricated polypropylene vessel with 2 mL of acetonitrile (CH3CN) containing 5.0 mM cross-hnkers. After incubation at 20 °C for 30 min, with 30 s of sonication every 10 min, the excess cross-linker solution was removed and the samples were washed extensively with acetonitrile, acetone, and hexane. After they were dried with N2, the samples were subject to the next chemical step. Twenty maleimide-grafted substrates were incubated at 20 for 1 h in... 

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