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Characterization and controlled release studies of 4-(2,4 dichlorophenoxy) butyrate and 2-(3-chlorophenoxy) propionate nanohybrids

Controlled release formulations were developed by intercalation of organic anions, namely 4- (2,4-dichlorophenoxy)butyrate (DPBA) and/or 2-(3-chlorophenoxy)propionate (CPPA) into the inorganic Zn-Al layered double hydroxide (ZAL) and zinc layered single hydroxide (ZLH)interlayers. Both anions, DPBA...

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Main Author: Abdul Rahman, Nor Shazlirah Shazlyn
Format: Thesis
Language:English
Published: 2012
Online Access:http://psasir.upm.edu.my/id/eprint/33767/1/FS%202012%2084%20IR.pdf
http://psasir.upm.edu.my/id/eprint/33767/
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spelling my.upm.eprints.337672015-04-08T06:57:19Z http://psasir.upm.edu.my/id/eprint/33767/ Characterization and controlled release studies of 4-(2,4 dichlorophenoxy) butyrate and 2-(3-chlorophenoxy) propionate nanohybrids Abdul Rahman, Nor Shazlirah Shazlyn Controlled release formulations were developed by intercalation of organic anions, namely 4- (2,4-dichlorophenoxy)butyrate (DPBA) and/or 2-(3-chlorophenoxy)propionate (CPPA) into the inorganic Zn-Al layered double hydroxide (ZAL) and zinc layered single hydroxide (ZLH)interlayers. Both anions, DPBA and CPPA are herbicides, a group of herbicides which function by mimicking the action of auxins and plant growth hormones. In this study, the nanohybrid compounds were synthesized by direct co-precipitation and anion exchange method for ZAL nanohybrids while direct reaction of zinc oxide with both anions under aqueous solution was applied for the formation of ZLH nanohybrids. Simultaneous intercalation of the dual herbicides was confirmed by the expansion of the interlayer spacing from 8.9 Å in the ZAL to 25.1 Å and 26.9 Å for the nanohybrid prepared by direct and ion-exchange method while ZLH shows higher basal spacing up to 28.7 Å due to higher charge density which can accommodate more guest anions into the ZLH interlayers compared to ZAL. Generally, the loading percentage obtained from simultaneous equation derived from UV-Vis spectrophotometer data for DPBA was found to be higher than CPPA. Result shows, nanohybrid synthesized by co-precipitation method contain of 2.5 % CPPA + 41.4 % DPBA while the percentage loading of the nanohybrid synthesized by anion-exchange method is 8.6 % CPPA + 53.9 % DPBA. Dual intercalation of both herbicides anions into ZLH resulted in percentage loading of 25.3% CPPA + 78.4 % DPBA. The high content of DPBA indicates that it is the dominant species and preferentially intercalated into the host interlayers than CPPA. In addition, DPBA anion has two chlorine atoms attached to the benzene ring therefore interacts more strongly with the positive charged layers. The simultaneous release profiles of both anions from their respective nanohybrids into sodium carbonate aqueous solution were best described by the pseudo-second order kinetic. This demonstrates the potential application of layered materials as hosts especially for the preparation of a controlled release formulation of the two herbicides simultaneously. The bulky anionic size, orientation and interaction with the positively charged inorganic interlayer could affect the degree of intercalation as well as the release of these herbicides from the host interlamelae. 2012-06 Thesis NonPeerReviewed application/pdf en http://psasir.upm.edu.my/id/eprint/33767/1/FS%202012%2084%20IR.pdf Abdul Rahman, Nor Shazlirah Shazlyn (2012) Characterization and controlled release studies of 4-(2,4 dichlorophenoxy) butyrate and 2-(3-chlorophenoxy) propionate nanohybrids. Masters thesis, Universiti Putra Malaysia.
institution Universiti Putra Malaysia
building UPM Library
collection Institutional Repository
continent Asia
country Malaysia
content_provider Universiti Putra Malaysia
content_source UPM Institutional Repository
url_provider http://psasir.upm.edu.my/
language English
description Controlled release formulations were developed by intercalation of organic anions, namely 4- (2,4-dichlorophenoxy)butyrate (DPBA) and/or 2-(3-chlorophenoxy)propionate (CPPA) into the inorganic Zn-Al layered double hydroxide (ZAL) and zinc layered single hydroxide (ZLH)interlayers. Both anions, DPBA and CPPA are herbicides, a group of herbicides which function by mimicking the action of auxins and plant growth hormones. In this study, the nanohybrid compounds were synthesized by direct co-precipitation and anion exchange method for ZAL nanohybrids while direct reaction of zinc oxide with both anions under aqueous solution was applied for the formation of ZLH nanohybrids. Simultaneous intercalation of the dual herbicides was confirmed by the expansion of the interlayer spacing from 8.9 Å in the ZAL to 25.1 Å and 26.9 Å for the nanohybrid prepared by direct and ion-exchange method while ZLH shows higher basal spacing up to 28.7 Å due to higher charge density which can accommodate more guest anions into the ZLH interlayers compared to ZAL. Generally, the loading percentage obtained from simultaneous equation derived from UV-Vis spectrophotometer data for DPBA was found to be higher than CPPA. Result shows, nanohybrid synthesized by co-precipitation method contain of 2.5 % CPPA + 41.4 % DPBA while the percentage loading of the nanohybrid synthesized by anion-exchange method is 8.6 % CPPA + 53.9 % DPBA. Dual intercalation of both herbicides anions into ZLH resulted in percentage loading of 25.3% CPPA + 78.4 % DPBA. The high content of DPBA indicates that it is the dominant species and preferentially intercalated into the host interlayers than CPPA. In addition, DPBA anion has two chlorine atoms attached to the benzene ring therefore interacts more strongly with the positive charged layers. The simultaneous release profiles of both anions from their respective nanohybrids into sodium carbonate aqueous solution were best described by the pseudo-second order kinetic. This demonstrates the potential application of layered materials as hosts especially for the preparation of a controlled release formulation of the two herbicides simultaneously. The bulky anionic size, orientation and interaction with the positively charged inorganic interlayer could affect the degree of intercalation as well as the release of these herbicides from the host interlamelae.
format Thesis
author Abdul Rahman, Nor Shazlirah Shazlyn
spellingShingle Abdul Rahman, Nor Shazlirah Shazlyn
Characterization and controlled release studies of 4-(2,4 dichlorophenoxy) butyrate and 2-(3-chlorophenoxy) propionate nanohybrids
author_facet Abdul Rahman, Nor Shazlirah Shazlyn
author_sort Abdul Rahman, Nor Shazlirah Shazlyn
title Characterization and controlled release studies of 4-(2,4 dichlorophenoxy) butyrate and 2-(3-chlorophenoxy) propionate nanohybrids
title_short Characterization and controlled release studies of 4-(2,4 dichlorophenoxy) butyrate and 2-(3-chlorophenoxy) propionate nanohybrids
title_full Characterization and controlled release studies of 4-(2,4 dichlorophenoxy) butyrate and 2-(3-chlorophenoxy) propionate nanohybrids
title_fullStr Characterization and controlled release studies of 4-(2,4 dichlorophenoxy) butyrate and 2-(3-chlorophenoxy) propionate nanohybrids
title_full_unstemmed Characterization and controlled release studies of 4-(2,4 dichlorophenoxy) butyrate and 2-(3-chlorophenoxy) propionate nanohybrids
title_sort characterization and controlled release studies of 4-(2,4 dichlorophenoxy) butyrate and 2-(3-chlorophenoxy) propionate nanohybrids
publishDate 2012
url http://psasir.upm.edu.my/id/eprint/33767/1/FS%202012%2084%20IR.pdf
http://psasir.upm.edu.my/id/eprint/33767/
_version_ 1643830965502476288
score 13.211869

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