Poly planarizing coatings

Currem field characteristics measured wiih conjugated polymers sandwiched between an indium-tin oxide (ITO) anode and an aluminum cathode are usually hole dominated and are, consequently, appropriate for testing injection/lransport models for the case of unipolar current How. Data shown in Figure 12-1 refer to injection-limited currents recorded on typically 100 nm thick spin-coated films of derivatives of poly(y d/"fi-phenylenevinylene) (PPV) and a planarized poly(/ /" -pheny-leue) employing a Keilhley source measure unit. The polymers were ... 

Acetylcholineesterase A 350 pM diameter coherent imaging fiber coated on the distal surface with a planar layer of analyte-sensitive polymer that was thin enough not to affect the fiber s imaging capabilities. It was applied to a pH sensor array and an ACh biosensor array (each contain 6000 optical sensor). Fibers were coated with an immobilized layer of poly (hydroxyethylmethacrylate)-N-flurosceinylacrylamide and AChE-fluorescein isothiocyanate isomer poly (acryloamide-co-N-acryl oxysuccinimide), respectively. The response time of the pH sensor was 2 s for a 0.5 unit increase in pH. The biosensor had a detection limit of 35 pM ACh and a linear response in the range 0.1 mM. [90]... 

Petschek [4] used heterocyclic rigid-rod polyionomers, including poly(pyr-idinium) salt, (III), and poly(benzimidazole-sulfonate), (IV), for coating directionally onto charged surfaces to impart planar alignment and pre-tilt to the surfaces. 

Fig. 9.19. (left) A schematic of the molecular order of the reactive LC molecules in a coated thin film retarder. The order is forced to be planar by the rubbed poly-imide. (right) An image of a uniaxial planar wet-coated retarder viewed in between two crossed polarisers and its orientation with respect to the crossed polarisers. (A) Analyser, (P) polariser, and (R) retarder. 

At the early stage of the development of the heart-on-a-chip, a PDMS microfluidic network was combined with planar electrode array to measure the extracellular potential from individual adult cardiomyocytes [54]. Another microfluidic device with an array of electrodes was developed to electrically measure the metabolic profile of cardiomyocytes and optically measure cell contractility [55]. Grosberg et al. first introduced a tissue level heart-on-a-chip to measure the contractility of neonatal cardiac muscle tissue [52]. In the design, eight muscular thin films (MTF) were fabricated on a chip. A layer of poly(N-isopropylacrylamide) (PIPAAm) dissolved at below 35 °C is spin-coated on top of a glass slide (Fig. 5A). Subsequently, a PDMS layer was coated on top of the PIPAAM layer. The PDMS layer was used to seed neonatal rat ventricular cardiomyocytes. The substrate seeded with cells is placed in the bath and the film layers were manually cut to fabricate an array of two opposite rows of four rectangular film layers of MTFs. The MTFs are peeled off after PIPAAm is dissolved as a solution when kept below 35 °C. Finally, electrodes are placed on the top and the bottom of MTFs. 

Nanostructured and planar films of poly(p-xylylene) have been fabricated by an oblique angle polymerization method. Subsequently, these films were coated with cobalt by an electroless deposition method [104],... 

Extrusion with wide exit slits is a special case. Planar films of 20-100 m in thickness, for example, are produced with wide exit slits. The film is then chilled by cold rolling or in water baths (melt-molding or chill-rolling method). Wide exit slits are also used in what is called extrusion coating of paper or cardboard with poly(ethylene). Papers thus treated can then be heat-sealed. 

Hollmann, O., Czeslik, C. (2006). Characterization of a planar poly(acrylic acid) brush as a materials coating for controlled protein immobilization. Langmuir, 22, 3300-3305. http //dx.doi.org/ 0.1021/la0531 lOy. 

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