Composite for Controleed Release of Small Molecules in Aquatic Environments

Abstract

A composite material formulated for slow release of a small molecule in seawater includes a porous inorganic oxide framework and micelles embedded within the pores of the framework. The micelles include a surfactant and a small molecule, the surfactant being present in the composite material at no more than 80 parts by weight per 100 parts by weight inorganic oxide, the composite material being stable in seawater for releasing the small molecule over at least 20 days.

1 . A method for preparing a composite material comprising:
 providing a liquid source of an inorganic oxide;   hydrolyzing the liquid source of an inorganic oxide in a polar solvent to form a sol;   incorporating a surfactant and a small organic molecule with molecular weight of less than 1000 in the sol, the surfactant being present in the sol at no more than 80 parts by weight per 100 parts by weight of inorganic oxide; and   solidifying the sol to form the composite material incorporating the inorganic oxide in a porous inorganic oxide framework and in which the small molecule and surfactant are present in pores of the framework.   
     
     
         2 . The method of  claim 1 , wherein the porous inorganic oxide framework comprises at least 50 wt % silica. 
     
     
         3 . The method of  claim 1 , wherein the inorganic oxide framework is derived from bis(trimethoxysilylethyl)benzene, tetramethyl orthosilicate, or a combination thereof. 
     
     
         4 . The method of  claim 3 , wherein a ratio of moles of silica derived from bis(trimethoxysilylethyl)benzene:moles silica derived from tetramethyl orthosilicate in the silica framework is at least 30:70. 
     
     
         5 . The method of  claim 1 , wherein pores of the inorganic oxide framework have an average pore diameter of less than 10 microns. 
     
     
         6 . The method of  claim 1 , wherein pores of the inorganic oxide framework have an average pore diameter at least 2 nm. 
     
     
         7 . The method of  claim 1 , wherein the inorganic oxide framework, as measured after surfactant extraction, has a BET surface area of at least 5 m 2 /g. 
     
     
         8 . The method of  claim 1 , wherein the small organic molecule is an anti-foulant. 
     
     
         9 . A method for preparing a composite material comprising:
 providing a liquid source of an inorganic oxide;   hydrolyzing the liquid source of an inorganic oxide in a polar solvent to form a sol;   incorporating a surfactant and a small organic molecule with molecular weight of less than 1000 in the sol, the surfactant being present in the sol at no more than 80 parts by weight per 100 parts by weight of inorganic oxide; and   solidifying the sol to form the composite material incorporating the inorganic oxide in a porous inorganic oxide framework and in which the small molecule and surfactant are present in pores of the framework,   wherein a ratio of moles of silica derived from bis(trimethoxysilylethyl)benzene:moles silica derived from tetramethyl orthosilicate in the silica framework is at least 30:70, and   wherein the small organic molecule is an anti-foulant.