Polyethylene thin film preparation

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. 

When welding polyethylene and polypropylene, clean, freshly cul surfaces should be prepared, and nitrogen should be used in the torch because a thin film of oxide prevents a satisfactory bond. sNeil Bartlett kindly supplied a description of this technique. 

Preparation of Samples. Polyethylene and polypropylene powder were treated with 0.5% by weight of the antioxidants in tetrahydrofuran. The solvent was removed at reduced pressure, and thin films were molded at 160 °C for 15 min. 

Sliding microtome, which is used for preparing thin films of polyethylene. 

Experimental results on the band dispersion in o-bond polymers are very limited due to difficulty in preparing thin films with oriented chains [20, 31, 32, 62]. Here, we introduce the band dispersion of quasi-one-dimensional polymer polyethylene. Early work on the band structure study was carried out on systems with alkyl chains and was aimed at understanding the electronic structure of polyethylene, in particular, the possible existence of one-dimensional band structure in thin films where molecular chains assemble via weak interchain interactions. There is renewed interest in the band dispersions as they determine carrier transport properties in nanoscale molecular electronics [63]. 

In 1991, Basche and Moerner included perylene in polyethylene [71]. The small and rigid perylene molecule has good emission and triplet properties, but absorbs in a difficult spectral region, around 445 nm. Because the spectral jumps we discuss here are mainly consequences of matrix dynamics, we must shortly discuss sample preparation. The samples of [71] were made from low-density polyethylene (crystallinity 25%), doped at low concentration with perylene, and were quickly quenched from the melt to liquid nitrogen temperature to reduce light scattering. The thin films thus obtained were 10 to 20 pm thick. The polymer structure is thus expected to be dominantly amorphous. 

Soft, thin films, with improved cuttability, suitable for packaging materials, were prepared by blending polyethylene, a mixture of LDPE and HDPE, with EPDM or atactic polypropylene, aPP S. Sakane, K. Minato, M. Takashige, Japanese Patent 000,052, 5 Jan 1979, Appl. 03 June 1977, to Idemitsu Petrochemical Co., Ltd. 

Thin films can be cast from solutions of crystalline or noncrystalline polymers where the film thickness is controlled by the solution concentration. Polyethylene films have been cast from boiling dilute solutions in xylene [21]. In most cases, a glass slide is dipped into the solution and suspended to dry in the vapors of the solvent to permit slow and uniform drying. Roche et al [22] prepared poly(butylene terephthalate) (PBT) in a 1% solution in hexafluoroisopropanol (HFIP) by... 

An immunosensor based on amine-functionalized CNT-SPE was described for detection of the cardiac troponin T, an important marker of acute myocardial infarction. The disposable sensor was fabricated by squeezing an adhesive carbon ink containing carbon nanotubes onto a polyethylene terephthalate substrate forming a thin film. The use of CNTs increased the reproducibility and stability of the sensor, and the amine groups permitted a nonrandom immobilization of antibodies against cardiac troponin T. Another example of the use of carboxylated CNTs is found by the work presented by Rafiee and Fakhari, who prepared a composite based on CNTs and Nafion for the development of a biosensor for the determination of insulin. Carboxylated CNTs plus Nafion were dispersed in water under ultrasonic conditions to get a homogeneous suspension and then a certain volume of that dispersive solution was dropped on the carbonaceous surface of the SPE. 

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