Nanosized silica modified with carboxylic acid as support for controlled release of herbicides.

Abstract

Hexagonal mesoporous silica modified with carboxylic acid (SiAc) has been obtained by reaction between chloroacetic acid and 3-aminopropyltrimethoxysilane, which was immobilized on porous material by a sol-gel process in the presence of an n-dodecylamine template. SiAc was characterized by TG, FT-IR, (29)Si NMR, (13)C NMR, SEM, surface charge density, surface area and porous diameter, which proved that the carboxylic group was chemically bonded to an inorganic structure, and the material presented a nanometric structure with spheres <50 nm and porous diameter of 10 nm. Herbicides 2,4-D and picloram were anchored on SiAc porous gel to produce the materials named SiD and SiPi, respectively. The controlled release of picloram from the SiAc was less than that of 2,4-D. After 26 days of releasing, 4.43 × 10(-5) mol L(-1) of picloram was delivered by SiPi, and 5.0 × 10(-5) L(-1) was released from the SiD in 30 days.

• Authors: Alexandre G S Prado, Aline O Moura, Alecio R Nunes
• Journal: Journal of agricultural and food chemistry (J Agric Food Chem) Vol. 59 Issue 16 Pg. 8847-52 (Aug 24 2011) ISSN: 1520-5118 [Electronic] United States
• PMID: 21728319 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Carboxylic Acids
• Delayed-Action Preparations
• Herbicides
• 2,4-Dichlorophenoxyacetic Acid
• Silicon Dioxide
• Picloram

Topics

• 2,4-Dichlorophenoxyacetic Acid (administration & dosage)
• Carboxylic Acids (chemistry)
• Delayed-Action Preparations (chemistry)
• Herbicides (administration & dosage)
• Nanoparticles (chemistry)
• Picloram (administration & dosage)
• Silicon Dioxide (chemistry)