Collodion -► nitrocellulose

Nobel invented gelatinous dynamite in 1875 by accident. He investigated the effect of nitroglycerine on the collodion (nitrocellulose in a mixture of ether and alcohol) that he used to treat a cut finger and found that it produced a tough plastic material with adjustable viscosity and high water resistance. 

The substances generally used as osmotic membranes include collodion (nitrocellulose of 11-13.5 per cent nitrogen) regenerated cellulose, obtained by denitration of collodion gel cellophane that has never permitted to dry after manufacture bacterial cellulose, obtained by the action of certain strains of bacteria rubber, poly (vinyl alcohol) polyurethances poly (vinyl butyral) and polychlorotrifluoroethylene. At present gel cellophane is most widely used. 

In the plant at Kriimmel [4] nitrocellulose was boiled with water in kiers of 14 m3 capacity. S-type was boiled for 6-8 hr, and collodion nitrocellulose (PE-type) for only 3 hr. 

Plastic films can be formed from a number of polymers two of the most common are collodion (nitrocellulose) and polyvinyl formal (Formvar). A number of other plastic materials can be used for thin films, some with specific advantages (101). Plastic films are usually prepared either by spreading a drop of solution of the plastic (in an appropriate solvent) onto a clean water surface, or by stripping off a film that has been coated onto a clean, flat surface (such as a glass slide) onto the surface of clean water. 

During this time, Pick s [3] studies of dialysis with collodion (nitrocellulose) membranes, which led to his eponymous law, and Graham s exhaustive studies of liquid diffusion [4] and gas permeation [5] provided the basis for interpreting and analyzing membrane performance. Graham is credited with the first use of the term dialysis to describe selective diffusion across semi-permeable membranes. 

Improved membranes have been the key to recent advances in ultrafiltration. The finest niter papers have pore diameters of as small as 1000 nm (1 micron) whereas ultrafilter membranes can be made with pore diameters from 1000 nm to as small as 2-3 nm. For many years cellophane or freshly formed films from collodion (nitrocellulose) were used, but now a number of manufacturers supply strong, flexible, and durable membranes of remarkably uniform pore size yet with high porosity, permitting rapid flow of water. Porous glass membranes have also been developed as well as porous carbon. Po rous ceramic with a microporous coating provides an ultrafilter highly resistant to high temperature and chemical attack. 

Sir Joseph Swan, as a result of his quest for carbon fiber for lamp filaments (2), learned how to denitrate nitrocellulose using ammonium sulfide. In 1885 he exhibited the first textiles made from this new artificial sHk, but with carbon fiber being his main theme he failed to foUow up on the textile possibihties. Meanwhile Count Hilaire de Chardoimet (3) was researching the nitrocellulose route and had perfected his first fibers and textiles in time for the Paris Exhibition in 1889. There he got the necessary financial backing for the first Chardoimet silk factory in Besancon in 1890. His process involved treating mulberry leaves with nitric and sulfuric acids to form cellulose nitrate which could be dissolved in ether and alcohol. This collodion solution could be extmded through holes in a spinneret into warm air where solvent evaporation led to the formation of soHd cellulose nitrate filaments. 

Membrane filtration has been used in the laboratory for over a century. The earliest membranes were homogeneous stmctures of purified coUagen or 2ein. The first synthetic membranes were nitrocellulose (collodion) cast from ether in the 1850s. By the early 1900s, standard graded nitrocellulose membranes were commercially available (1). Their utihty was limited to laboratory research because of low transport rates and susceptibiUty to internal plugging. They did, however, serve a useflil role in the separation and purification of coUoids, proteins, blood sera, enzymes, toxins, bacteria, and vimses (2). 

Shortly afterwards (1885) Vieille s powder was introduced in France under the name of B powder (Poudre B). Vieille utilized two types of nitrocellulose for its manufacture collodion cotton CP2, soluble in a mixture of ether and alcohol and forming the powder dough cotton CPi, insoluble in a mixture of ether and alcohol, incorporated into the powder mass in the form of unchanged fibres... 

Pyroxylins. A group of Nitrocelluloses with N content ranging from 10% and less to about 12.65%. The lower N members (see also under Collodion Cotton in Vol 3, C394-R) are used... 

The development of plastics accompanied synthetic fibers. The first synthetic plastic with the trade name Celluloid was made in 1870 from a form of nitrocellulose called pyroxylin, the same substance used to produce the first rayon. Celluloid was developed in part to meet the demand for expensive billiard balls, which at the end of the nineteenth century were produced from ivory obtained from elephant tusks. John Wesley Hyatt (1837-1920) combined pyroxylin with ether and alcohol to produce a hard substance called collodion. Hyatt s collodion, like Bernigaut s original rayon, was unstable and potentially explosive. He solved this problem by adding camphor to the collodion to produce a stable hard plastic he called Celluloid. 

Collodions These are the fluid preparation intended for external use. The vehicle of collodion are volatile (e.g. ethyl alcohol) in nature and when applied on the skin (with brush or rod) evaporates to the skin and leaving a flexible, protective film. The film producing agent is pyroxylin (nitrocellulose) and for flexibility colour oil is added. 

Hemp Nitrate (Nitrohemp) (In French Nitro-chanvre). Nitrohemp resembles cotton nitrocellulose or nitrojute in its properties. It may be prepared by nitrating hemp with mixed nitric-sulfuric acid. Trench (Ref 2) proposed using it as1 a basic ingredient in commercial explosives. Other components were collodion cotton, resin, ozokerite, glycerin etc Ref Daniel (1902), 773... 

Cotone collodio. (Collodion Cotton, abbrd as CC). See under Nitrocellulose... 

COLLODION Cellulose Nitrate Solution, Nitrocellulose Solution, Pyroxylin Solution, Box Toe Gum Flammable Liquid, II 2 3 3... 

Collodion cotton is supplied wet to dynamite factories with a water content up to 30-35%. Some factories use it directly in this form, although the presence of water is detrimental to the uniformity of the gel produced. In the majority of factories nitrocellulose is dried before use. 

The operation proceeds as follows a brass mesh and a linen disk are put on the bottom of a cylinder at position 1, and then 20 kg (dry substance) of wet nitrocellulose is poured in from above. Commonly used types of nitrocellulose (guncotton with collodion cotton) are packed alternately in layers, which in fact... 

After analysis each form of nitrocellulose (guncotton, collodion cotton, pyror collodion cotton) is batched separately into a linen bag which for convenience and safety is stored in an air-tight iron vessel (to protect the nitrocellulose from drying up and becoming dusty). Nitrocellulose is batched by charges, the size of which depends on the dimensions and the type of apparatus used. In France, for instance, a total charge of nitrocellulose (CPt and CP2) is 20 kg when dehydrated in a hydraulic press or 30 kg when dehydrated in a centrifuge. 

When treating the nitrocellulose mixture with solvent, only collodion cotton is dissolved and converted into a colloidal state. Guncotton is incorporated into the colloidal mass in the form of fibres. Thus by the solubility of a mixture of nitrocellulo-ses in a mixture of alcohol and ether, we mean the total solubility of the mixture. 

The batching of nitrocellulose consists of weighing the guncotton and collodion cotton in a ratio which gives a mixture of suitable nitrogen content with the required total solubility. 

During World War I and later attenuated ballistite (Ballistite ATT) in which the nitroglycerine was partly replaced by DNT was used in France. To prevent excessive attenuation the collodion cotton was partly replaced by high nitrated nitrocellulose (CP,) ... 

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