Page 10 - Adsorbents fundamentals and applications

CONTENTS vii

6 Silica Gel, MCM, and Activated Alumina 131
6.1. Silica Gels: Preparation and General Properties / 131
6.2. Surface Chemistry of Silicas: The Silanol Groups / 134
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6.3. The Silanol Number (OH/nm ) / 135
6.4. MCM-41 / 139
6.5. Chemical Modification of Silicas and Molecular
Imprinting / 141
6.6. Activated Alumina / 146
6.7. Activated Alumina as Special Sorbents / 150
References / 154

7 Zeolites and Molecular Sieves 157
7.1. Zeolite Types A, X, and Y / 158
7.1.1. Structure and Cation Sites of Type A Zeolite /
158
7.1.2. Structure and Cation Sites of Types X and Y
Zeolites / 160
7.1.3. Examples of Molecular Sieving / 161
7.2. Zeolites and Molecular Sieves: Synthesis and Molecular
Sieving Properties / 164
7.2.1. Synthesis of Zeolites A, X, and Y / 164
7.2.2. Organic Additives (Templates) in Synthesis of
Zeolites and Molecular Sieves / 165
7.3. Unique Adsorption Properties: Anionic Oxygens and Isolated
Cations / 173
7.4. Interactions of Adsorbate with Cations: Effects of Cation
Site, Charge, and Ionic Radius / 175
7.4.1. Cation Sites / 175
7.4.2. Effects of Cation Sites on Adsorption / 180
7.4.3. Effects of Cation Charge and Ionic Radius / 183
References / 187

8 π-Complexation Sorbents and Applications 191

8.1. Preparation of Three Types of Sorbents / 192
8.1.1. Supported Monolayer Salts / 193
8.1.2. Ion-Exchanged Zeolites / 197
8.1.3. Ion-Exchanged Resins / 201
8.2. Molecular Orbital Theory Calculations / 202
8.2.1. Molecular Orbital Theory — Electronic Structure
Methods / 202
8.2.2. Semi-Empirical Methods / 203