计算溶液所需的质量、体积或浓度。
,适用于对基线干扰要求严格的色谱和分析工作流程。
室温,充氩,干燥。常规运输 。请查阅批次 COA 获取详细规格。
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在色谱分析、有机合成和交叉偶联反应领域已被 24 篇同行评审文献引用。
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. The 3A form is made by substituting potassium cations for the inherent sodium ions of the 4A structure, reducing the effective pore size to ~3Å, excluding molecules of diameter >3Å (for example: ethane). 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.
Molecular sieves, 3Å is a UOP-type zeolite 3Å.It is widely employed as a sorbent.
Regeneration or Activation:
A saturated molecular sieve can be restored to its original capacity by regeneration, the principle of which involves changing the conditions surrounding the adsorbent to correspond to a very low equilibrium capacity. In general, the greater the difference between the equilibrium capacities of adsorption and regeneration, the more rapid and complete the regeneration.
The sieve may be regenerated in one of four ways:
1. Thermal reactivation –The maximum regeneration temperature for Silica is 300°C.
2. Pressure reactivation
3. Passing an appropriate fluid through the gel bed at normal temperature and pressure.
4. Displacement of adsorbates by passing a high concentration of molecules in a fluid through the bed.
The kinetics of the adsorption of water-vapor by employing molecular sieve 3Å has been studied in various temperature ranges (25-80°C and water dew points from -69 to 17°C).
分类树(Taxonomy Tree)
| 界(kingdom) | 无机化合物 |
|---|---|
| 超类(Superclass) | 混合金属/非金属化合物 |
| 类(Class) | 后过渡金属含氧阴离子化合物 |
| 亚类(Subclass) | 后过渡金属硅酸盐 |
| 中间层级节点(Intermediate Tree Nodes) | 暂无 |
| 直接上位类(Direct Parent) | 后过渡金属硅酸盐 |
| 其他上位类(Alternative Parents) | 杂硅酸盐 后过渡金属盐 准金属盐 无机钠盐 无机氧化物 |
| 分子骨架(Molecular Framework) | 暂无 |
| 取代基(Substituents) | 无机类金属盐 - 无机氧化物 - 无机过渡金属盐 - 无机盐 - 无机钠盐 - 后过渡金属硅酸盐 - 硅酸盐 |
| 描述(Description) | 该化合物属于无机化合物中的后过渡金属硅酸盐类。这类化合物中最大的氧阴离子为硅酸根,且非氧阴离子中的最重原子为后过渡金属。 |
| 外部描述符(External Descriptors) | 暂无 |
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| 批号(Lot Number) | 证书类型 | 货号 |
|---|---|---|
| 分析证书 | M100324 | |
| 分析证书 | M100324 | |
| 分析证书 | M100324 | |
| 分析证书 | M100324 | |
| 分析证书 | M100324 | |
| 分析证书 | M100324 | |
| 分析证书 | M100324 | |
| 分析证书 | M100324 | |
| 分析证书 | M100324 | |
| 分析证书 | M100324 | |
| 分析证书 | M100324 | |
| 分析证书 | M100324 | |
| 分析证书 | M100324 | |
| 分析证书 | M100324 | |
| 分析证书 | M100324 | |
| 分析证书 | M100324 | |
| 分析证书 | M100324 | |
| 分析证书 | M100324 | |
| 分析证书 | M100324 | |
| 分析证书 | M100324 | |
| 分析证书 | M100324 | |
| 分析证书 | M100324 | |
| 分析证书 | M100324 |