Title

POLYMER-SILICA MATERIALS FOR SELECTIVE METAL CAPTURE BY THE SOL-GEL APPROACH

Presentation Type

Presentation

Abstract

Recently, sol-gel chemistry and the use of organic-inorganic hybrid materials have received much attention for use in the remediation of aqueous streams contaminated with heavy metals. Heavy metals are present in local streams from a multitude of sources and have very harmful effects on biological processes. Remediation of these streams is necessary to ensure the health of the ecosystem. There are many different methods for remediation of contaminated waters, but many are either too expensive or have insufficient selectivity for metal ions for them to be cost-effective. Silica polyamine composites (SPC) made via the sol-gel process have been investigated recently because of their high selectivity for specific metal ions. The SPC starting material is synthesized from a mixture of tetramethoxysilane (TMOS), methyltrimethoxysilane (MTMOS) and chloropropyltrimethoxysilane (CPTMOS). This material is converted to the SPC BP-1 by a reaction with the polymer polyallylamine (PAA). When BP-1 is further modified with various organic ligands, the resulting composites show high affinities for specific metal ions and have shown to selectively recover valuable metal ions up to 98% pure. Recently, batch capacities and breakthrough testing have been conducted to determine the metal capacity and the selectivity of the sol-gel composites. The composites made via the sol-gel process have comparable, and sometimes better, capacities and selectivity than commercial composites. Also, the sol-gel process is more environmentally benign than the current methods for the production of SPC and with comparable capacities the sol-gel process can be a viable candidate for the future production of SPC.

Category

Physical Sciences

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Apr 15th, 10:20 AM Apr 15th, 10:40 AM

POLYMER-SILICA MATERIALS FOR SELECTIVE METAL CAPTURE BY THE SOL-GEL APPROACH

UC 327

Recently, sol-gel chemistry and the use of organic-inorganic hybrid materials have received much attention for use in the remediation of aqueous streams contaminated with heavy metals. Heavy metals are present in local streams from a multitude of sources and have very harmful effects on biological processes. Remediation of these streams is necessary to ensure the health of the ecosystem. There are many different methods for remediation of contaminated waters, but many are either too expensive or have insufficient selectivity for metal ions for them to be cost-effective. Silica polyamine composites (SPC) made via the sol-gel process have been investigated recently because of their high selectivity for specific metal ions. The SPC starting material is synthesized from a mixture of tetramethoxysilane (TMOS), methyltrimethoxysilane (MTMOS) and chloropropyltrimethoxysilane (CPTMOS). This material is converted to the SPC BP-1 by a reaction with the polymer polyallylamine (PAA). When BP-1 is further modified with various organic ligands, the resulting composites show high affinities for specific metal ions and have shown to selectively recover valuable metal ions up to 98% pure. Recently, batch capacities and breakthrough testing have been conducted to determine the metal capacity and the selectivity of the sol-gel composites. The composites made via the sol-gel process have comparable, and sometimes better, capacities and selectivity than commercial composites. Also, the sol-gel process is more environmentally benign than the current methods for the production of SPC and with comparable capacities the sol-gel process can be a viable candidate for the future production of SPC.