The Colloid Chemistry of Silica

Title Page......Page 1
Half Title Page......Page 3
Copyright......Page 4
1994 Advisory Board......Page 5
FOREWORD......Page 6
ABOUT THE EDITOR......Page 7
ASSOCIATE EDITORS......Page 8
Acknowledgments......Page 9
DEDICATION......Page 11
1 Colloid Chemistry of Silica An Overview......Page 14
Colloidal Dispersions and Colloid Science......Page 19
Sols, Gels, and Powders......Page 20
Colloidal Silica—Stability and Aggregation......Page 21
Gelation, Coagulation, Flocculation, and Coacervation......Page 23
Fractal Approach to Colloid Systems......Page 25
Colloid Chemistry of Silica—State of the Art......Page 28
Silica Nucleation, Polymerization, and Growth: Preparation of Monodisperse Silica Sols......Page 29
Stability of Silica Sols......Page 30
Silica Surface......Page 34
Particle Size and Characterization Techniques......Page 51
Sol-Gel Science and Technology......Page 53
Gels and Powders......Page 54
Uses of Silica—From the Caves of Altamira and Cro-Magnon to Silicon Valley and Outer Space......Page 55
Acknowledgment......Page 57
References......Page 58
2 Silica Nucleation, Polymerization, and Growth Preparation of Monodispersed Sols......Page 61
Manufacturing Methods of Silica Sols and Their Characteristics......Page 62
Manufacturing Methods of Surface-Modified Silica Sols......Page 71
Future Trend in Silica Sol Manufacturing......Page 74
References......Page 76
3 The Formation and Interfacial Structure of Silica Sols......Page 77
Experimental Details......Page 78
Results and Discussion......Page 79
Acknowledgements......Page 91
References......Page 92
4 Synthesis and Characterization of Colloidal Model Particles Made from Organoalkoxysilanes......Page 93
Theory and Earlier Work......Page 95
Experimental Details......Page 101
Results and Discussion......Page 104
Conclusions......Page 118
References......Page 119
5 Synthesis of Nanometer-Sized Silica by Controlled Hydrolysis in Reverse Micellar Systems......Page 122
Experimental Details......Page 123
Results......Page 124
Discussion......Page 129
References......Page 135
6 Formation of Silica Gels Composed of Micrometer-Sized Particles by the Sol-Gel Method......Page 138
Conditions for the Formation of Micrometer-Sized Particles......Page 139
Mechanism of the Formation of Micrometer-Sized Particles......Page 141
Applications......Page 148
References......Page 150
7 Stability of Aqueous Silica Sols......Page 151
Origins of Colloid Stability......Page 154
References......Page 163
8 Surface Structure of Amorphous and Crystalline Porous Silicas Status and Prospects......Page 164
Structural Aspects in Silica Chemistry......Page 165
Survey of Methods for Characterizing the Silica Surface......Page 167
Current View of the Silica Surface......Page 174
Conclusions......Page 178
References......Page 179
9 Infrared Study of Chemical and H-D Exchange Probes for Silica Surfaces......Page 181
Results......Page 182
Discussion......Page 194
References......Page 196
10 Fourier Transform Infrared and Raman Spectroscopic Study of Silica Surfaces......Page 197
Experimental Details......Page 200
Results......Page 201
Discussion......Page 209
References......Page 219
11 Surveying the Silica Gel Surface with Excited States......Page 221
Experimental Details......Page 223
Results and Discussion......Page 224
Conclusions......Page 239
References......Page 241
12 Surface Chemistry and Surface Energy of Silicas......Page 243
Experimental Details......Page 244
Results and Discussion......Page 246
References......Page 253
13 Variable-Temperature Diffuse Reflectance Fourier Transform Infrared Spectroscopic Studies of Amine Desorption from a Siliceous Surface......Page 254
Experimental Details......Page 257
Results and Discussion......Page 258
Conclusions......Page 262
References......Page 263
14 Multinuclear NMR Spectroscopy Studies of Silica Surfaces......Page 265
Underivatized Silica Surface......Page 266
Derivatized Silica Surfaces......Page 273
Experimental Details......Page 276
References......Page 277
15 New Separation Methods for Characterizing the Size of Silica Sols......Page 279
Sedimentation Field-Flow Fractionation......Page 280
Flow Field-Flow Fractionation......Page 284
Size-Exclusion Chromatography......Page 288
Hydrodynamic Chromatography......Page 293
Capillary-Zone Electrophoresis......Page 296
References......Page 299
16 Characterization of Colloidal and Particulate Silica by Field-Flow Fractionation......Page 301
Theory......Page 304
Experimental Details......Page 309
Results and Discussion......Page 314
Conclusions......Page 327
List of Symbols......Page 330
References......Page 331
17 Interpretation of the Differences Between the Pore Size Distributions of Silica Measured by Mercury Intrusion and Nitrogen Adsorption......Page 333
Experimental Details......Page 334
Results and Discussion......Page 336
Conclusions......Page 345
Acknowledgments......Page 346
References......Page 347
18 Sol-Gel Processing of Silica......Page 348
Hydrolysis and Condensation of Aqueous Silicates......Page 350
Hydrolysis and Condensation of Silicon Alkoxides......Page 352
Gelation and Aging......Page 359
Drying......Page 363
Structure and Consolidation of Dried Gels......Page 366
Surface Structure and Chemistry......Page 372
Fiber Formation......Page 374
Particle Formation......Page 377
Film Formation......Page 379
Summary......Page 383
Acknowledgments......Page 384
References......Page 385
19 The Chemistry of Hydrolysis and Condensation of Silica Sol-Gel Precursors......Page 390
Hydrolysis......Page 391
Condensation......Page 400
Conclusions......Page 403
References......Page 404
20 Chemistry and Properties of Porous, Organically Modified Silica......Page 406
General Considerations......Page 407
Preparation of Porous Materials......Page 409
Acknowledgments......Page 418
References......Page 419
21 Evaporation and Surface Tension Effects in Dip Coating......Page 420
Experiments on Evaporating Thin Films......Page 424
Multicomponent Solvents and Surface Tension Gradients......Page 428
Summary: Time Scales......Page 434
References......Page 436
22 Formation of Uniform Precipitates from Alkoxides......Page 438
Uniform Silica Particles......Page 440
Size-Dependent Aggregation Rates......Page 444
Uniform Titania Particles......Page 448
Conclusions......Page 449
References......Page 451
23 Development of Silica Gels and Impact of Silica Research on Studies of Other Colloidal Systems......Page 453
Thomas Graham......Page 454
Walter A. Patrick......Page 455
Ralph K. Iler......Page 457
References......Page 463
24 Industrial Synthetic Silicas in Powder Form......Page 464
Nomenclature and Classification of Types......Page 467
Differences among the Types......Page 468
After-Treated Synthetic Amorphous Silicas......Page 471
Applications......Page 473
Questions Regarding Registration and Approval......Page 483
Toxicology......Page 484
References......Page 485
25 Adsorptive Properties of Porous Silicas......Page 488
Compacts of Pyrogenic Powders......Page 489
Precipitated Silicas......Page 490
Silica Gels......Page 492
Zeolitic Silicas......Page 495
References......Page 497
26 Silica Gels from Aqueous Silicate Solutions Combined 29Si NMR and Small-Angle X-ray Scattering Spectroscopic Study......Page 499
Silicon-29 NMR Spectroscopy......Page 500
Small-Angle X-ray Scattering......Page 505
Aging of Aqueous Silica Gels......Page 509
References......Page 512
27 Surface Chemistry of Silica Coatings of Titania......Page 514
Why Coat Titania with Silica?......Page 515
How To Coat Titania with Silica......Page 519
Iler DS Deposition Process......Page 521
References......Page 537
28 Dense Silica Coatings on Micro- and Nanoparticles by Deposition of Monosilicic Acid......Page 539
Experimental Details......Page 541
Results......Page 544
Discussion......Page 553
References......Page 556
Preparation Procedures......Page 557
Applications......Page 559
Conclusions......Page 568
References......Page 569
30 The Uses of Soluble Silica......Page 571
Additional Reading......Page 576
31 Silicon-Aluminum Interactions and Biology......Page 577
A Test of the Concept: Prolylhydroxylase Activity......Page 579
Aluminum in Biological Systems......Page 580
A Test of the Al-Si Balance Hypothesis......Page 582
The Exclusion Mechanism......Page 583
The Significance of the Environmental Si:Al Balance......Page 586
Silicic Acid: Geochemistry and Health......Page 587
References......Page 589
32 Preparation and Uses of Silica Gels and Precipitated Silicas......Page 592
Nomenclature and Manufacture......Page 593
Applications......Page 597
References......Page 600
Additional Reading......Page 601
33 Colloid Chemistry of Silica: Research in the Former Soviet Union......Page 602
Historical Sketch......Page 604
Preparation and Stabilization of Silica Hydrosols......Page 605
Preparation of Silica Gels and Powders, Geometric Modification of Silicas, and Studies of Structural Characteristics......Page 608
Surface Chemistry of Amorphous Silica......Page 614
Investigations of Silica Surface Processes by Physical and Physicochemical Methods......Page 618
Physical and Chemical Adsorption......Page 622
Adsorption from Solutions......Page 626
Ion Exchange......Page 627
Action of Ionizing Radiation and Mechanical Activation......Page 628
Silica Coatings......Page 630
Properties of Water in Dispersed Silica......Page 631
Theoretical Investigations......Page 632
References......Page 635
Affiliation Index......Page 650
A......Page 652
C......Page 653
D......Page 655
E......Page 656
F......Page 657
I......Page 658
M......Page 659
O......Page 660
P......Page 661
R......Page 662
S......Page 663
W......Page 668
Z......Page 669