Aluminium-Based Surfactant Mesophases Structurally and Morphologically Controlled by Anions

• Published in: Journal of porous materials 1998-05, Vol.5 (2), p.133-138
• Main Authors: Yada, Mitsunori, Hiyoshi, Hiroaki, Machida, Masato, Kijima, Tsuyoshi
• Format: Article
• Language: English
• Subjects: Aluminium; Aluminum; Anions; Mesophase; Morphology; Sodium; Specific surface; Sulfates
• ISSN: 1380-2224; 1573-4854
• DOI: 10.1023/A:1009697421580

Aluminium-based dodecyl sulfate mesophases were synthesized by the homogeneous precipitation from a mixture of aluminium nitrate, sodium dodecyl sulfate, urea and water with or without five kinds of additional anions. The addition of monovalent Cl^sup -^, CH^sub 3^COO^sup -^ and HCOO^sup -^ anions yielded a hexagonal mesophase, whereas F^sup -^ anions induced a different mesophase. The crystallinities of these mesophases increased in the following order: NO^sub 3^^sup -^ and Cl^sup -^>CH^sub 3^ COO^sup -^>HCOO^sup -^>F^sup -^, corresponding to the reverse order of affinity for Al^sup 3+^. The resulting mesophases were also largely affected in morphology by the anion species added to form worm-like shaped particles for NO^sub 3^^sup -^ and/or Cl^sup -^ anions, and widely varying shapes of particles for the others. On calcination, these mesophases were transformed into α-alumina particles with macro pores having the specific surface area of ca. 20 m^sup 2^g^sup -1^. On the other hand, the addition of divalent SO^sub 4^^sup 2-^ anions or the single use of aluminium sulfate led to a mesophase with a structural period as long as 6 nm, which was deorganized into a layered phase with an interlayer spacing of 1.4 nm.[PUBLICATION ABSTRACT]