别名:4A分子筛; 英文别名:4A; 英文名称:Molecular sieves, 4 Å; 储存温度:干燥; 运输条件:常规运输; 产品介绍:4A分子筛的孔径约4埃，其主要适用于气体，液体的干燥。可吸附H2O、NH3、H2S、CO2、SO2、CO、氯甲烷、溴甲烷、乙炔、乙烷、乙烯、丙烯等。广泛用于油田伴生气、天然气等的干燥。也广泛用于乙醇的脱水。也用于真空玻璃等的防结露。用作色谱试剂。选择性吸附剂。催化剂或催化剂载体。用于甲烷、乙烷和丙烷的分离。练焦气中乙烯的分离。 也用作干燥剂。空气，天然气，烷烃，致冷剂等气体和液体的深度干燥；氩气的制取和净化；电子元件和易受潮变质物质的静态干燥；油漆，聚脂类，染料，涂料中作脱水剂Choosing a Molecular Sieve: 1. The preferential adsorption of one molecule over another depends upon pore diameter and mesh size. 2. The dynamic capacity of the silica gel for adsorbing a particular compound is governed by the internal surface area; the greater the surface area, the greater the dynamic capacity. 3. Rate of adsorption and sharpness of resolution are dependent chiefly on particle size and column packing; a fine particle size gives optimum sharpness of resolution. 4. Liquids are most readily adsorbed from solvents in which they are least soluble; a good solvent makes a good desorbing agent. 5. Highly polar liquids are readily adsorbed. Compounds having hydroxyl groups, or containing oxygen are strongly adsorbed. 6. For similar compounds, the higher the molecular weight the higher the selectivity. 7. For hydrocarbons of similar molecular weight, adsorptivity increases with the number of double bonds. Molecular sieves are crystalline metal aluminosilicates having a three-dimensional interconnecting network of silica and alumina tetrahedra. Natural water of hydration is removed from this network by heating to produce uniform cavities which selectively adsorb molecules of a specific size. This 4A form with sodium ions has the effective pore opening of 4?, thus excluding molecules of effective diameter >4? (for example: propane). The 8 to 12-mesh type is common in liquid-phase applications. Molecular sieves are considered a universal drying agent in polar and nonpolar media.
