Poly contact angle measurements

Upadhyay et al. [98] used primarily correlated XPS and water contact angle measurements to study the surface degradation and recovery of amorphous films of a PMMA and a poly (aryl ether ether ketone) (PEEK). Surface modification of the films was carried out in a dielectric barrier discharge (DBD) unit, samples being treated with different dose levels of dielectric discharge. The modified (treated) samples were then stored for one month and re-examined. Figure 35 shows C(ls) and 0(1 s) XPS envelopes and their curve-fitting deconvolutions,... 

Takei, Y. G., Aoki, T., Sanui, K., Ogata, N., Sakurai, Y, and Okano, T. Dynamic contact angle measurement of temperature-responsive surfaces properties for poly(Af-isopropylacrylamide) grafted surfaces. Macromolecules, 1994, 27, 6163—6166. 

Thin films of polyethylene, poly(ethylene-co-5-norbomen-2-yl acetate), and poly-(cthylene-co-5-norbomen-2-ol) were prepared on glass slides and contact angle measurements of water droplets determined. Testing results are provided in Table 2. 

A series of membrane materials have been tested for the performance of water removal from hydrazine, including poly(vinyl alcohol) (PVA), ethyl cellulose, PS, and ABS (93). Contact angle measurements served to estimate the hydrophilic or hydrophobic properties. Apolar materials showed higher separation factors than polar materials. Encouraging results with respect to the performance were obtained with modified ethyl cellulose and ABS membranes. 

Counterion Interactions with Water and Poly cations. The wide range of contact angles measured for the different counterions is no doubt related to the extent of their interaction with water relative to that with the polycations. 

Procedure. With the exception of poly (ethylene terephthalate), 20/ films of each polymer were prepared by the evaporation or approximately 4% solutions in quartz or glass dishes of 50 cm.2 area for extraction experiments. For contact angle measurements, films were evaporated on acid-cleaned microscope slides by a dipping technique. Tetrahydrofuran was used with poly (vinyl chloride), methylene chloride with the other polymers. 

Contact Angle Measurements. The angle of contact of 93° for poly(L-norleucine) has been reported previously. Problems of preparing uniform adherent films of poly(L-methionine) and hysteresis effects combined to make measurements of 0 very imprecise it is estimated at 55° 10°. No measurements at all were possible with poly(L-leucine) for similar reasons. 

Therefore, this chapter presents preliminary evidence indicating the effect and interrelationship between primary and secondary molecular motions on thrombogenesis, independent of morphological order and/or crystallinity. The polymer selected for this study was an amorphous elastomeric hydrophobic polymer of poly[(trifluoroethoxy) (fluoroalkoxy)phosphazene] (PNF) I (5, 6). The salient aspects of this polymer are that (1) the onset of the secondary molecular motions occurs between -160° and - 120°C (2) the side chain motion can be altered by irradiation (ultraviolet, electron beam, or gamma) (3) no apparent ultrastructure morphology exists (4) the side chains can be derivatized (5) and (5) the polymer can be readily coated onto our extracorporeal test shafts (7) and irradiated accordingly. Additionally, contact angle measurements of the homopolymer (8) and the PNF (9), 19.7 and 15.0 dyn/cm2, respectively, indicated that the fluorinated side chains comprised the surface to be interfaced in the extracorporeal blood studies. 

PLLA, PDLLA, Poly(ethylene glycol)(PEG)-PLLA, PEG-PDLLA Nonwoven scaffold TE Contact angles measurement, SEM, in vitro osteoprogenitor cell culture, alkaline phosphatase activity (Badami et al. 2006)... 

E. Kiss, J. Samu, A. Toth, I. Bertoti, Novel ways of covalent attachment of poly (ethylene oxide) onto polyethylene surface modification and characterization by XPS and contact angle measurements. Langmuir 12, 1651—1657 (19%)... 

For instance, surface segregation in water vapor of the blend films prepared with polystyrene-hZocfc-poly(L-glutamic acid) PS27-Zt-PGA2o improved the reorientation of the hydrophilic polypeptide block at the interface (Fig. 5.22).[129] Water contact angle measurements supported the surface enrichment of polypeptide segments as a... 

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