Regioselective acetylation of carbohydrates and diols catalyzed by tetramethyl-ammonium hydroxide in water

Four cubic mesoporous silicates (CMS), one unmodified and three grafted with amine, carboxylic and cyano surface functional groups, were prepared, characterised and compared as adsorbents for tetramethyl ammonium hydroxide (TMAH) from aqueous solution. The adsorption process was studied as a function of molecular size and CMS pore volume. Sorption on the unmodified, cyano- and carboxylic-grafted adsorbents closely followed the Langmuir model while adsorption on the amine-treated silicate conformed to the Freundlich model. A comparison of the adsorbent pore volume and the volume of sorbed TMAH molecules suggested that monolayer sorption occurred, there being some evidence that surface functional groups influenced the adsorption process. The presence or absence of structural order, as defined by X-ray diffraction analysis, had no significant influence on the adsorption, as all materials, both ordered and disordered, had relatively high adsorption capacities.

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Preparation and use of a mesoporous silicate material for the removal of tetramethyl ammonium hydroxide (TMAH) from aqueous solution

Journal of Chemical Technology & Biotechnology ◽

10.1002/jctb.508 ◽

2001 ◽

Vol 76 (12) ◽

pp. 1216-1222 ◽

Cited By ~ 25

Author(s):

Brian P Kelleher ◽

Aidan M Doyle ◽

Thomas F O'Dwyer ◽

Benjamin K Hodnett

Keyword(s):

Aqueous Solution ◽

Ammonium Hydroxide ◽

Silicate Material ◽

Tetramethyl Ammonium ◽

Mesoporous Silicate ◽

Tetramethyl Ammonium Hydroxide

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Adhesion of Photoresist Pattern Baked at 80 to 325°C in Tetramethyl-ammonium-hydroxide Aqueous Solution

Japanese Journal of Applied Physics ◽

10.1143/jjap.31.3725 ◽

1992 ◽

Vol 31 (Part 1, No. 11) ◽

pp. 3725-3730 ◽

Cited By ~ 14

Author(s):

Akira Kawai ◽

Hitoshi Nagata ◽

Masasuke Takata

Keyword(s):

Aqueous Solution ◽

Ammonium Hydroxide ◽

Tetramethyl Ammonium ◽

Tetramethyl Ammonium Hydroxide

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Application of Ozone Related Processes to Mineralize Tetramethyl Ammonium Hydroxide in Aqueous Solution

International Journal of Photoenergy ◽

10.1155/2013/191742 ◽

2013 ◽

Vol 2013 ◽

pp. 1-7 ◽

Cited By ~ 6

Author(s):

Chyow-San Chiou ◽

Kai-Jen Chuang ◽

Ya-Fen Lin ◽

Hua-Wei Chen ◽

Chih-Ming Ma

Keyword(s):

Aqueous Solution ◽

Reaction Time ◽

Semiconductor Industry ◽

Ammonium Hydroxide ◽

Wet Etching ◽

Etching Process ◽

Magnetic Catalyst ◽

Tetramethyl Ammonium ◽

Tetramethyl Ammonium Hydroxide

Tetramethyl ammonium hydroxide (TMAH) is an anisotropic etchant used in the wet etching process of the semiconductor industry and is hard to degrade by biotreatments when it exists in wastewater. This study evaluated the performance of a system combined with ultraviolet, magnetic catalyst (SiO2/Fe3O4) andO3, denoted as UV/O3, to TMAH in an aqueous solution. The mineralization efficiency of TMAH under various conditions follows the sequence: UV/O3> UV/H2O2/O3>H2O2/SiO2/Fe3O4/O3>H2O2/O3>SiO2/Fe3O4/O3>O3> UV/H2O2. The results suggest that UV/O3process provides the best condition for the mineralization of TMAH (40 mg/L), resulting in 87.6% mineralization, at 60 min reaction time. Furthermore, the mineralization efficiency ofSiO2/Fe3O4/H2O2/O3was significantly higher than that ofO3,H2O2/O3, and UV/H2O2. More than 90% of the magnetic catalyst was recovered and easily redispersed in a solution for reuse.

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