Solution-cast polymer glasses

Polymer Films. The polymer films were prepared by casting 5% toluene solutions onto glass microscope slides. After air drying in a fume hood, the films were vacuum dried. Film thicknesses were typically 0.05 mm. 

Materials. Bisphenol A-epichlorohydrin condensate 1 (Eponol-55-B-40, Shell Chemical Co.) was precipitated from chloroform solution by addition of methanol three successive times prior to utilization. Polymer films of 1.5 and 15 pm were cast onto glass plates from chloroform solution. 

The concept of thin films of a molecularly imprinted sol-gel polymer with specific binding sites for a target analyte is general and can be applied also to electrochemical sensors. For example, a sensor to detect parathion in aqueous solutions is based on films cast on glass substrates and on glassy carbon electrodes (Figure 6.14).12... 

Fluorinated poly(imide-ether-amide)s are readily soluble in organic solvents like dimethylformamide (DMF), N-methylpyrrolidone (NMP), pyridine or tetrahydrofu-ran (THF) and give flexible films by casting of such solutions. These polymers exhibit decomposition temperatures above 360°C, and glass transition temperatures in the 221-246° C range. The polymer films have a low dielectric constant and tough mechanical properties. 

Monomer I (MAA) was dissolved in methanol and I moI% of crosslinking agent, tetraethyleneglycol dimethylacrylate (TEGDMA) (Polysciences, Inc., Warrington, PA), and I wt% of initiator, 2,2-dimethoxy-2-phenyI acetophenone (DMPA Aldrich, Milwaukee, WI) were added. The solution was cast on glass plates equipped with spacers and reacted under an UV source with an intensity of 1 mW/cm for 30 min. Polymer I (PMAA) was removed from the plates, washed in deionized water to remove all unreacted monomers, cut into discs, and dried in a vacuum oven. 

The polymer film was cast on glass plates from a 20% (by weight) solution of polymer in dimethylformamide. After the film was dried at 50°C for 40 min it was removed from the glass plate by immersion in water. No difference was found in the properties of sulphonated products based on the P-1700 resin or P-3500 resin. 

Materials and Methods. The isomeric compositions of the four polybutadienes used are listed in Table I. Samples were prepared for infrared measurement from solutions of the polymer without further purification. Most films were cast from carbon disulfide solutions on mercury or on glass plates, but a few films were cast from hexane solutions to determine whether or not the solvent affected the radiation-induced behavior. No difference was observed for films cast from the different solvents. The films were cured by exposure to x-rays in vacuum. (Doses were below the level producing detectable radiation effects.) They were then mounted on aluminum frames for infrared measurements. The thicknesses of the films were controlled for desirable absorbance ranges and varied from 0.61 X 10 s to 2 X 10 3 cm. After measuring the infrared spectrum with a Perkin-Elmer 221 infrared spectrophotometer, the mounted films were evacuated to 3 microns and sealed in glass or quartz tubes (quartz tubes only were used for reactor irradiations). 

Solvent Casting. The polymer is mixed with the plasticizer in the required proportion and dissolved in methylene chloride to form a 10% solution. Films are cast from this solution on a glass plate using a Gardner knife. The films are allowed to dry overnight at room temperature, and any residual solvent is removed by heating for 10 hours in an oven at 110°C. The thickness of the dry film should be about 100 n. 

The polyamide-hydrazide 7 was prepared by solution polymerization in anhydrous dimethylacetamide from terephthaloyl chloride and p-amino-benzhydrazide at ca. 10 °C. The polyamide 8 resulted from the polycondensation of m-phenylenediamine with isophthaloyl chloride at —20 °C, whereas 9 was prepared by the reaction of terephthaloyl chloride with the complex diamine l,3-bis(3-aminobenzamide)benzene at —20 °C. The water flux and salt rejection through these membranes were summarized in Table 5. The polyamide-hydrazide (7) membranes were prepared from polymer solutions containing 6 7% polymer (Mv 3 34,000) by casting on glass plates. The material was placed in an oven for 30 60 min and coagulated in deionized... 

When developing membranes from a new polymer, practitioners of the empirical approach usually prepare a series of trial casting solutions based on past experience with similar polymers. Membrane films are made by casting onto glass plates and precipitation in a water bath. The casting solutions most likely... 

One of the first synthetic polymers to be blended with starch was poly(vinyl alcohol) (PVA). Otey et al.129,130 prepared cast films of starch and PVA from aqueous solutions containing a plasticizer (glycerol). Films were cast onto glass plates and air-dried at 130°C. Small amounts of crosslinking agent, such as formaldehyde,... 

The polymers studied are listed in Table I along with their sources and characterizations. Bulk samples were prepared in two steps. First, a thin film (2-10 mils) was obtained by casting onto glass from a solution... 

The PHEMA-fe-PMPS-fc-PHEMA amphiphilic ABA block copolymers were used to generate patterned calcium carbonate hlms with dimensions of several hundreds of microns using the photolithographic properties of the polysilane component [77]. PHEMA-fe-PMPS-fc-PHEMA was spin cast from THF solution onto glass substrates. On this polymer layer continuous hhns of calcium carbonate,... 

The chemical structure of the polyimide polymers (named PI-1 and PI-2) studied by Sekkat et al. is shown in Figure 12.12. They prepared the polymer samples by spin-casting onto glass substrates. PTl was cast from a cyclohexanone solution and PI-2 from 1,1,2,2- tetrachloroethane. The Tg values of PI-1 and PI-2 were determined to be 350°C and 252 C, respectively, by scanning calorimetry method. The thicknesses of the PI-1 and PI-2 films were, respectively, approximately 0.72 im and 0.14 im, and their respective optical densities were approximately 0.79 and 0.3 at 543.5 nm. Details of the preparation and characterization of the samples can be found in References 3 and 20. In their EFISH experiment, a typical corona poling technique was used to pole the samples, with a dc electric field about 2-3 MV/cm across a 1-2 lm thick polymer film. They used the SHG output from the EFISH experiment to in situ monitor the photochemical change in the third-order susceptibility of the PI-1 and PI-2 polymers. 

Copolyester of p-hydroxybenzoic acid with ethylene terephthalate (PHB-PET, 60/40) was supplied by Tennessee Eastman Kodak Co., whereas polyether imide (PEI) was provided by General Electric. Co. (Ultem 1000). These polymers were dissolved together in a mixed solvent of phenol and tetrachloroethane in the ratio of 60/40 by weight at 80°C for about a week. The polymer concentration of the solution was 2 wt7.. Various PHB-PET/PEI films were cast on glass slides at ambient temperature, then dried in a vacuum oven at 60°C for two weeks. Thicker films were prepared in Petri dishes for differential scanning calorimetric (DSC) studies. 

Figoh et al. [9] tried to overcome the limitation of the first MELM preparing well-defined capsule-containing membranes (Fig. 7.5E). These membranes were prepared adding the capsules, loaded with carrier-solvent, to the polymer membrane solution and then cast on a glass support. The gas... 

In a recent pubHcation, Alivisatos and co-workers reported the making of hybrid nanorods-polymer solar cells and their properties [122]. These solar cells were made by spin casting of a solution of both poly(3-hexylthiophene) (hole acceptor) and CdSe nanorods (electron acceptor) onto indium tin oxide glass substrates coated with poly(ethylene dioxythiophene) doped with polystyrene sulfonic acid and aluminum as a top contact. Nanorods have been used in composites so as to improve the carrier mobiHty. Indeed, the latter can be high for some inorganic semiconductors, but it is typically extremely low for conjugated polymers [123]. The use of the nanorods suppHes an interface for the charge transfer as well as a direct path for electrical transport. Also, because of their anisotropy, self-assembly of these nanorods is observed by electron microscopy. It shows... 

Films were prepared by solvent casting a filtered solution, 10% solids by weight of the polymer in distilled A,N-dimethylformamide, onto glass plates. The plates were placed in a forced air draft oven at 75°C for 1 h to evaporate the solvent. The films were then dried in a vacuum desiccator at 0.1 mm mercury for 24 h to insure complete removal of any residual solvent. The glass plates were washed with 0.1% aqueous Ivory soap solution, then rinsed with deionized water and absolute ethanol prior to use. 

The isolated polyether matrix was modeled using polypropylene glycol (2000 MW) and isotactic polypropylene oxide. The polypropylene glycol was degassed and placed over molecular sieves to remove residual water present in the polyol. The isotactic polypropylene oxide was isolated by repeated crystallization from acetone (9). Inherent viscosity was 1.85 in benzene (0.5% concentration) at 25°C. Films of the isotactic polypropylene oxide were cast onto glass plates (cleaned as described previously) from a 6% solution of the polymer in N,N-dimethylformamide, dried in a forced air draft oven for 1 h at 75°C, and then placed in a vacuum desiccator (0.1 mm mercury) for 24 h to insure complete removal of residual solvent. 

The typical polymer LED structure is shown in Figure 7.3. In order to fit in the quartz finger dewar which is inserted in the microwave cavity (see Section 1.3.1 below), the width of the devices was limited to 4.5 mm. They were all fabricated on ITO-coated glass, which was the positive electrode. The active area of the devices was 7 mm. PPV layers were deposited by spin coating the appropriate precursor and thermally converting it CN-PPV was spin-cast directly from solution [3]. The deposition of the polymers was followed by evaporation of the metal electrode from which electrons were injected into the devices [3,9,25,26,28,29]. In the case of the PPV- and PPE-based devices, that electrode was Al-encapsulated Ca, which yielded a higher device efficiency than an A1 electrode [9,25,26,28,29]. The thickness of the emissive PPV and PPE layers was 600 and 300 nm, respectively. Derivatives of PPE dissolved in toluene were spin-coated onto the ITO substrates, followed by e-beam or thcnnal evaporation of A1 or Ca/Al electrodes in a base chamber pressure of 10 torr. The PPV/CN-PPV diodes used A1 as the electron-injecting electrode [3], The thickness of the PPV layer was 120 nm, and that of the CN-PPV layer was 100-200 nm. Finally, copper wires were bonded to the A1 and no layers with silver paint. 

Instrumentation. Thin films of the material to be studied (mostly metals) are deposited onto insulating substrates (glass, mica) for a typical setup, see Fig. 7.27. Films of intrinsically conducting polymers are deposited by casting from their solution or by electropolymerization [262, 263]. 

For the spectroscopic and sorption experiments, the silver-polymer complex solution (20 wt.% in water) was cast on a glass plate and dried under a nitrogen atmosphere. The cast films were finally dried overnight in a vacuum at room temperature to remove any residual water. After drying completely, the films were lifted from the glass plate and FTIR measurements performed. The FTIR spectra for the solid-state interactions of the silver-PVMK complex and olefin are shown in Fig. 9-6. 

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