Cellulose electric conductivity

Practical applications have been reported for PVP/cellulosics (108,119,120) and PVP/polysulfones (121,122) in membrane separation technology, eg, in the manufacture of dialysis membranes. Electrically conductive polymers of polyaniline are rendered more soluble and hence easier to process by complexation with PVP (123). Addition of small amounts of PVP to nylon 66 and 610 causes significant morphological changes, resulting in fewer but more regular spherulites (124). 

Modification of cotton textiles by chemical plating of their surfaces with cobalt (II) or nickel (II) salts produced metallized fibers and fabrics with high electrical conductivity and the capability to transport and dissipate thermal energy (109). The heat capacity of cellulose acetate fibers was increased by treatment with epoxy compounds (110). 

Light Microscopic Method. Phase contrast microscopy (PCM) accurately assesses fiber exposure levels for fibers 5 pm in length and >0.25 pm in diameter. Furthermore, PCM cannot differentiate between asbestos and nonasbestos fibers. Currently, the standard method for the determination of airborne asbestos particles in the workplace is NIOSH Method 7400, Asbestos by Phase Contrast Microscopy (NIOSH 1994a). OSHA considers that sampling and analytical procedures contained in OSHA Method ID-160 and NIOSH Method 7400 are essential for obtaining adequate employee exposure monitoring. Therefore, all employers who are required to conduct monitoring are required to use these or equivalent methods to collect and analyze samples (OSHA 1994). In NIOSH Method 7400, asbestos is collected on a 25 mm cellulose ester filter (cassette-equipped with a 50 mm electrically-conductive cowl). The filter is treated to make it... 

From these results, it may be concluded that the degree of refining has a relatively small effect on the bulk conductivity of paper. A small change in the electrical properties is also observed for different pulp types in paper. These variations are not significant when compared with the variations resulting from a change in relative water content. For cellulose the conductivity increases with water content by a factor of 1014 from 0% to 20% water content 8). 

Furthermore, composite films of nanofibrillated cellulose (NFC)/Ppy and NFC/ PPy-silver NP are a suitable candidate for use in biomedical applications. Due to the electrical conductivity and strong antimicrobial activity of these silver composites, they can be used in various applications, in particular, biomedical treatments and diagnostics. 

Our trials through published articles [20-22] to provide functional paper sheets with serving the previous drawbacks, and based on the characteristics of cellulose derivative-metal complexes, the CMC- and HEC-metal complexes were used as beater additives during the formation of paper sheets from wood pulp. The thermal degradation and magnetic and electrical conductivity properties were tested to evaluate the performance of paper product besides the strength properties. 

Electrospinning is applicable to a wide range of polymers like those used in conventional spinning, that is, polyolefine, polyamides, polyester, aramide, and acrylic, as well as biopolymers like proteins, DNA, and polypeptides, or others like electrically conducting, photonic and other polymers such as poly(ethylene oxide] (PEO], DNA, poly(acrylic acid] (PAA], polyQactic acid] (PEA], and also collagen, organics such as nylon, polyester, and acryl resin, and poly(vinyl alcohol] (PVA], polystyrene (PS], polyacrylonitrile (PAN], peptide, cellulose, etc. 

We may further refer to measurements on the electric conductivity of cellulose fibres as a function of regain by H. Mahlo, Melliani Textilber., 22 (1941) 609. At low moisture contents the resistance is very great, but drops rather abruptly beyond 6—7% regain in cotton and beyond about 10% regain in rayon. 

W.T. Soltes [24] described a technique for the thermal conversion of cellulosic material such as cotton, rayon, hemp or flax in a two stage process in the absence of oxygen to give a textile carbon, which was electrically conductive. This process was subsequently taken up commercially by Union Carbide. 

Si ieha and cowoikers [67] found that the degree of surface treatment of cellulose fibres can be determined from the electrical conductance of a distilled water suspension of the treated fibres. The measured conductance is a function of treatment c iditi( s such as discharge current, treatment time and availability of oxygm, and under certain conditions can be related to the mechanical properties of resulting composites, see Hg. 13. Increased conductance obviously results fiom the increasing concentration of water-soluble itmic species, for example the acids listed in section 32.2. 

The interactions at fiter/thermoplastic interfaces depend on the surface properties of the composite components. Therefore, to produce reliable composite materials one needs efficient, rapid and rqiroducible method for the evaluation of the treatment level of cellulose surfaces. In this study it has been shown that electrical conductance of the distilled water suspensions of treated cellulose fibers is a reliable measure of the surface treatment and it relates directly to the physical properties of composites. 

Allan GG, Negri AR (1992) The microporosity of pulp. Tappi J 75(3) 239-244 Allan GG, Carroll JP, Jimenez G, Negri AR (1998) Enhancement of the optical properties of a bagasse newsprint furnish by fibre-wall-filler. Cellulose Chem Technol 32(3 ) 339-347 Carmona GJ, Morales GJ, Cehnente RR (2003) Morphological control of precipitated calcite obtained by adjusting the electrical conductivity in the Ca(0H)2-H20-C02 system. J Cryst Growth 249(3 ) 561-571... 

While the original, basic low-performance materials such as clays and chalks are still used very widely, the modern market is placing increasing pressure on manufacturers to offer fillers that give some additional value, such as improvement in mechanical properties. They are increasingly called upon to provide other value-added functions, such as mechanical properties. UV or heat stability, thermal or electrical conductivity, dimensional stability, or flame retardancy. Increased interest in environmental aspects is creating demand now for fillers that are based on vegetable materials such as cellulose. 

Emulsion pol5nnerization in heterogeneous systems (166) has been used to prepare processable conductive composites of polyaniline-poly(alkyl methacrylate). Polyaniline composites have also been prepared via dispersion polymerization (167-169). In snch studies colloidal dispersions of electrically conductive polyaniline particles have been prepared using vinyl methyl ether (168) or methyl cellulose (170) stabilizers. 

Sampie assembly (The assembly is shown in Figure 3). Conductive filter holder consisting of a 25-mm diameter, 3-piece cassette having a 50-mm long electrically conductive extension cowl. Backup pad, 25-mm, cellulose. Membrane filter, mixed-cellulose ester (MCE), 25-mm, plain, white, 0.4-to 1.2- j,m pore size. 

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