Grafted films, membranes

Alternatively, the film is placed between two perforated lead plates and grafted with monomer M by the mutual method. After grafting, the film is now placed between the two perforated lead plates taking precautions that only the ungrafted portions of the grafted film are exposed to gamma radiations in the presence of monomer M2. Schematically, the preparation of the mosaic membrane is shown in Fig. 2. 

Figure 2 Preparation of mosaic membrane (a) film grafted with monomer Mi and (b) Mi grafted film further grafted with monomer M2.

Brack, H.-P, Ruegg, D., Biihrer, H., Slaski, M., Alkan, S. and Scherer, G. G. 2004. Differential scanning calorimetry and thermogravimetric analysis investigation of the thermal properties and degradation of some radiation-grafted films and membranes. Journal of Polymer Science Part B Polymer Physics 42 2612-2624. 

Abstract We review various methods for the photochemical grafting of organic polymers to various substrates including, organic films, membranes, planar gold, silicon wafers, glass, silica gel, silica nanoparticles, and polydimethylsiloxane micro-channels. An emphasis is placed on photoinitiated synthesis of polymer brushes from planar gold and silicon. 

Figure 29 Temperature dependence of the permeability of p-nitrophenol for A-ProOMe grafted films. The permeability (P) was calculated from the equation, P = KVjAC, where k, V, A, and C are the slope of the permeation-time curve, the volume of the receiver chamber, the surface area of the membrane, and the concentration of p-nitropenol in the donor chamber, respectively.

Although many radiation-grafted materials have been discovered, only a limited number of them have been commercially utilized. One of the first successful applications was the use of grafted films in battery separators. Other possibilities are in ion exchange resins and membranes for separation processes. The textile industry represents opportunities in improving... 

T. Momose, H. Yoshioka, I. Ishigaki and J. Okamoto, Radiation drafting of a,a,(3-trifluorostyrene onto poly(ethylene-tetrafluoroethylene)film by preirradiation method. I. Effects of preirradiation dose, monomer concentration, reaction temperature, and film thickness, J. Appl. Polym. Sci., 1989, 37, 2817-2826 II. Properties of cation exchange membrane obtained by sulfonation and hydrolysis of the grafted film, 1989, 38, 2091-2101 III. Properties of anion exchange membrane obtained by chloro-methylation and quatemization of the grafted film, 1990, 39, 1221-1230. 

Table 1 Common base polymer films used for the preparation of radiation grafted PC membranes [43]...

Sulfonation of PEP- and ETFE-based grafted films at PSI was performed by using 30% chlorosulfonic acid in dichloromethane (at 95 C, 5 h) and membranes with reasonably good sulfonic acid content have been observed. Sulfonation conditions almost identical to those used at PSI have been used by others for the sulfonation of PFA-g-polystyrene films, i.e., a mixture of chlorosulfonic acid and 1,1,2,2-tetrachloroethane (30 70 v/v, 90 °C, 5h) [133]. Phadnis et al. [83] performed the sulfonation of styrene-acrylic acid grafted FEP films in concentrated sulfuric acid (at room temperature). Concentrated... 

Investigation of the structure, morphology, homogeneity, thermal and mechanical properties of both the grafted films and the membranes is important... 

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