Hierarchically Porous Silica Materials for the Encapsulation of Molecules of Interest

Abstract : This work concerns the preparation of silica materials with hierarchical porosity for the encapsulation of molecules of interest in the field of drug delivery and as biocatalysts. In order to reach this goal, the nano-emulsions were chosen as templates for the macropores of the material because of the homogeneous and small size of the emulsion droplets (less than 100 nm). The system Remcopal 4/decane/water was investigated and the optimal conditions for which nano-emulsion is formed via the phase inversion methods were determined. Adding micelles to the nano-emulsions does not affect its stability and can form a network of mesopores organized with a hexagonal symmetry. Hybrid materials which are hierarchically porous materials where the organic phase is still present, were doped with ketoprofen to study its release, which proved to be pH sensitive. Moreover, the study of the release of ketoprofen from the meso-macroporous material indicates that it is assisted by the micelles which are solubilized in the release medium. The second objective of this work was to use these porous materials as a biocatalyst for biodiesel synthesis from colza oil. For this application it was necessary that the materials are resistant to immersion in aqueous media. The study of the hydrothermal stability shows that the calcined material has the best stability in boiling water. Moreover, the material can withstand up to 550 ° C, the structure undergoes only minor damages. We also used a dual-mesoporous silica material prepared from hydrogenated and fluorinated micelles coexisting in the same solution. Thermal and hydrothermal evaluation indicates that these materials have two different decay kinetics corresponding to each of the two matrices having different pore sizes. The immobilization of lipase Mml was studied on the meso-macroporous calcined material and the dual-mesoporous material. The adsorption isotherms were used to demonstrate that the dual-mesoporous material can encapsulate more enzymes than its meso-macroporous counterpart. On the other hand, the enzyme activity, evaluated by the transesterification reactions, is more important for the calcined meso-macroporous material
Document type :
Theses
Complete list of metadatas

https://hal.univ-lorraine.fr/tel-01752225
Contributor : Thèses Ul <>
Submitted on : Thursday, March 29, 2018 - 1:38:55 PM
Last modification on : Tuesday, April 10, 2018 - 1:27:28 AM

File

DDOC_T_2016_0013_RIACHY.pdf
Files produced by the author(s)

Identifiers

  • HAL Id : tel-01752225, version 1

Collections

Citation

Philippe Riachy. Hierarchically Porous Silica Materials for the Encapsulation of Molecules of Interest. Other. Université de Lorraine, 2016. English. ⟨NNT : 2016LORR0013⟩. ⟨tel-01752225⟩

Share

Metrics

Record views

51

Files downloads

33