Nitrocellulose films

The membrane is critically important in osomometry. Selection of a membrane involves reconciliation of high permeability toward the solvent with virtual impermeability to the smallest polymer molecules present in the sample. Membranes of cellulose are most widely used. Commercially Regenerated cellulose film is a common source. The undried gel cellophane film is often preferred, but the dry film may be swollen in water (or in aqueous solutions of caustic or zinc chloride ) to satisfactory porosity. Useful cellulose membranes may also be prepared by denitration of nitrocellulose films/ and special advantages have been claimed for bacterial cellulose films. The water in the swollen membrane in any case may be replaced by a succession of miscible organic solvents ending with the one in which osmotic measurements are to be made. Membranes of varying porosity may be... 

Deposition of the analyte on nitrocellulose films instead of metal foils allows the removal of alkali ion contaminations by washing of the sample layer which results in better PD spectra. [163] Further improvements can be achieved by adsorption of the analyte molecules on top of an organic low-molecular weight matrix layer. [164,165]... 

Introduction. Today nitrocellulose is one of most important derivatives of cellulose used in industry and commerce, and a major product of the chemical industry. Its wide and manifold applications are due mainly to its extraordinary physical properties. Thus a protective coating of nitrocellulose varnish, a nitrocellulose film or a tube of smokeless powder — all are characterized by relatively high elasticity and mechanical strength. These properties are a direct consequence of the microstructure of cellulose, which is composed of highly oriented long-chain molecules of polysaccharide. Not only nitrocellulose, but also other derivatives of cellulose, such as other esters and ethers, demonstrate similar characteristics. 

It is well-known in practice that about 1% of the solvent remaining in the nitrocellulose film can be removed only with difficulty. In the instance of a nitrocellulose film over 1% acetone is still retained after evaporating and diying at 70°C for 75 hr, as reported by Miles [16a]. 

Fig. 97. Solvent retained by nitrocellulose films (50/i thickness) after exposure to air at 25°C (Baelz [48]). I—Cyclohexenyl acetate, II—methyl cyclohexanone, III—diacetone alcohol, IV—cyclohexanone, V—cellosolve acetate, VI—amyl acetate-ethyl alcohol I 1, VII—amyl acetate, VIII— methyl cellosolve acetate, IX—amyl acetate-toluene 1 1, X—butyl acetate-ethyl alcohol 1 1, XI—butyl acetate, XII—cellosolve, XIII—methyl-ethyl ketone, XIV—cellosolve-toluene 1 1, XV—methyl cellosolve, XVI—ethyl acetate, XVII—acetone.

Water absorption from a 40% calcium nitrate solution was studied by Gukhman, Petrov and Yakovlev [120], who found that a nitrocellulose film immersed in such a solution was capable of absorbing up to 50% of water. After 5 min the water content reached 15-20%, and after 15 min it amounted to 25-30%. 

It is also known that nitrocellulose or nitrocellulose film grows yellow as a result of prolonged exposure to sunshine. 

A fire of celluloid film that became a news item in Japan in recent years occurred in the National Modem Museum J). The fire, at about 14 47 on September 3, 1984, was caused by the spontaneous ignition of nitrocellulose films in the film storeroom on the fifth floor of the museum. The fire damaged a considerable number of the 3,000 reels of foreign movies that were stored there. On December 16, 1932, a disastrous fire caused by the burning of celluloid toys on a counter of Shirakiya Department Store resulted in the death of 14 saleswomen who could not escape and the injury of 21 other people. 

Photographic film was once made from nitroeellulose, a plastic made from wood or cotton, without the use of hydrocarbons. Nitrocellulose film is strong and dimensionally stable. It made an excellent substrate for the photographic emulsion, but it is extremely flammable. Nitrocellulose in a slightly different form is used to make smokeless gun and rocket propellant. A replacement polyester material with the same dimensional stability has been produced from hydrocarbons. The polyester film has little... 

Hercules AS, RS, SS. [Hercules] Nitrocellulose film-formers, bases for air-dry finishes, primers, surfacers, topcoats for transp( tation industry, lacquers, printing inks, adhesives, cements. 

RS Nitrocellulose. [Hercules] Nitrocellulose film-former for lacquers, inks, adhesives, nail polishes, and protective and decoa vt coating iq>plics. 

The nitrocellulose polymer substrate was a fully nitrated derivative of cellulose, in which the free hydroxyl groups are substituted by nitro groups, and is thus hydrophobic in nature. Researchers have shown that the immobilization of proteins on nitrocellulose surfaces rehes on hydrophobic interactions. However, polysaccharides, being rich in hydroxyl groups, are hydrophilic in nature (42,61). The molecular forces for the carbohydrate-nitrocellulose interaction remain to be characterized, but it has been suggested that the three-dimensional (3D) microporous configuration of the nitrocellulose on the slides and the macropolymer characteristics of polysaccharides play important roles for the stable immobilization of many polysaccharides on the nitrocellulose surface. The polysaccharide molecules immobilized onto the nitrocellulose film are in a nonsite-specific format (Fig. 3). 

FIG. 14 Dependence of the steady-state limiting current 4 on the concentration of o-glucose Cs h was measured at 0.5 V versus Ag/AgCl with film-coated glucose oxidase (180 rg)-BQ (30%)-carbon paste electrodes at a film thickness of (a) 50 /xm (nitrocellulose film), (b) 50 fim (dialysis membrane), and (c) 100 fjm (dialysis membrane). (From Ref. 33.)... 

Uses Plasticizer, softener for NR, SR, nitrile mbber, CR, vinyl, film sheeting, textile coatings, pkg. materials, adhesives, nitrocellulose films Features Monomeric does not affect cure gives vulcanizate with extremely good aging and elec, props. gives low temp, flexibility Properties APHA 35 m.w. 390 sp.gr. 0.985 dens. 8.2 Ib/gal vise. 375 cSt (0 C) pour pt. -60 E cloud pt. < -60 E flash pt. 420 E ref. index 1.4851... 

Uses Plasticizer for lacquers, printing inks antifoam agent solvent for nitrocellulose film-former, solvent for cosmetics, pharmaceuticals plas-ticizerforaq. pharmaceutical coatings, sustained-release drugs in food-pkg. adhesives... 

VA/crotonates/vinyl neodecanoate copolymer VA/crotonates/vinyl propionate copolymer VA/isobutyl maleate/vinyl neodecanoate copolymer Vinyl acetate Vinyl caprolactam/PVP/dimethylaminoethyl methacrylate copolymer film-former, cosmetics moisturizers Diglycol/CHDM/isophthalates/SIP copolymer film-former, cream rinses Polyquatemium-2 film-former, creams Acetylated lanolin Nitrocellulose film-former, creams/lotions Arachidyl behenate PVM/MA copolymer, isopropyl ester film-former, detergents PVM/MA copolymer film-former, dish detergents Hydrolyzed collagen film-former, disposable gloves Ethylene/methyl acrylate copolymer film-former, dusting powders Rice (Oryza sativa) starch film-former, dyes PVP/VA copolymer film-former, elastomers Dibutyl phthalate... 

Y.-H. Liu, J. Bai, X. Liang, D. M. Lubman, and P. J. Venta, Use of a nitrocellulose film substrate in matrix-assisted laser desorption/ionization mass spectrometry for DNA mapping and screening, AnaL Chem. 67, 3482-3490 (1995). 

Imniunoaffinity separations performed on a matrix-assisted laser desorption ionization-mass spectrometer (MALDI-MS) probe tip have given rise to the term PAMS (probe affinity MS) [134]. Antibiotin covalently bound to the surface of the probe allowed MS discrimination of bovine insulin with different degrees of biotinylation. The method has also been used to detect lysozyme in human tears by binding antilysozyme to the MS probe. Based on the same PAMS principle, modifications aimed to obtain faster and improved retention of Abs have been carried out by immobilizing the Abs on the probe via a nitrocellulose film instead of binding them directly to the MALDI probe surface [135]. The procedure allowed determination of a therapeutic peptide and one metabolite. 

Since A. Pick observed that gas molecules tend to pass through thin nitrocellulose films at different permeation rates for each gas, membrane-based gas separation has been studied extensively to look for better membrane materials and to apply this property to gas separation on an industrial scale. Numerous scientists have studied membrane materials with respect to transport... 

Facilitated diffusion was studied in immobilized liquid membranes using a system composed of a micro-porous nitrocellulose film impregnated with tri- -octylamine (TOA) in n-decane (Kalachev et al., 1992). 

Uses Plasticizer for lacquers, printing Inks antifoam agent solvent for nitrocellulose film-former, solvent for cosmetics, pharmaceuticals plasticizer for aq. pharmaceutical coatings, sustained-release drugs In food-pkg. adhesives Regulatory FDA 21CFR 175.105 USP/NF compliance ManufJDistrib. Alfa Aesar Alfa Chem ChemServIce Chemial SpA Mallinckrodt Baker Penta Mfg. Somerset Cosmetic Co. Spectrum Chems. Lab. Prods. Tianjin MId-Chem Unitex Universal Preserv-A-Chem Vertellus Perf. Materials Vertellus Spedalties Trade Names CItroflex 4 Uniplex 83... 

Using polymethylmethaciylate (PMMA) and nitrocellulose films we experimentally determined the modulus of elasticity E and tangent of the an e of mechanical losses tg S, employing the method of forced flectural oscillations of cantilevered films in accordance with a technique specially worked out for this purpose 10). The curves of mechanical losses versus frequency for the thinner films are steeper and are lifted toward greater frequences, as shrmld have been expected. Those data have been interpreted as evidence of the narrowing of relaxation time ctrum. 

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