Location: Conference Room of Basic Energy Science Building
Time: 2015.11.10 (Tuesday) 9:30 a.m.
Lecturer: Prof. Fran？ois Fajula, The French National Center for Scientific Research， France
Abstract:
The lecture will introduce three synthesis strategies developed in recent years in our group for the preparation of ordered porous materials:
1.Phospholipid-templated mesoporous supports for enzyme encapsulation
A new method of enzymes encapsulation involving sol–gel precipitation templated by bilayers of phospholipids is presented. It provides an organized network of phospholipids embedded in silica and allows protection of entrapped enzymes, as if they were entrapped in a biological membrane. The formation of a negative curvature in the rigid phospholipid bilayers is induced by adding ethanol to the aqueous medium. Dodecylamine stabilizes the structure and acts as a catalyst for silica condensation. Lactose avoids direct interaction of the enzymes with the silica walls at the interface of the lipids bilayer. Encapsulated enzymes show higher activities compared to traditional and commercial immobilized-enzymes. This new type of biological nanoreactor has been used to encapsulate simultaneously several enzymes. Examples showing the degradation of carcinogenic aromatics from aqueous and organic effluents and the conversion of carbon dioxide into methanol will be presented.
2.Stimuli-responsive micelles of hydrosoluble copolymers for the eco-synthesis of functional mesoporous materials
An original method for the preparation of functional mesoporous materials relies on the use of PolyIon Complex (PIC) micelles, whose role is double : they can direct the structure of the inorganic framework and confer a functionality to the final hybrid mesoporous material. PIC micelles are reversible dynamic assemblies of hydrosoluble polymers that result from electrostatic interactions between two polyions of opposite charge, one of them belonging to a double-hydrophilic block copolymer (DHBC). The micelle formation is reversible in water as a function of pH, which allows dissociating the micelles within the material, generating the ordered porosity at room temperature and neutral pH. A second advantage of using polyelectrolytes as structuring agents is the possibility to functionalize the silica pore surface. We will describe several possible preparation routes of functional hybrid silica-based mesoporous materials, as well as zeolites with multimodal porosity, using reversible complex micelles formed from different polyacids and polybases.
3.Conversion of polysaccharides into functional materials
Natural polysaccharides are gelling agents in the aqueous phase, due to the high level of dispersion of hydrocolloids. An effective method to prepare dry materials which retain the dispersion of the polymer hydrogel, namely polysaccharide aerogels, will be introduced. The diverse surface functionalities like hydroxy, carboxy or amino groups of the polysaccharide aerogels are accessible to catalysts and reactants and can be easily modified to tune the functionality of the materials.
Introduction:
After a PhD in physical chemistry prepared in Strasbourg (1978) and a post-doctoral stay at Texas A & M University (1980) Fran？ois Fajula joined the Ecole Nationale Supérieure de Chimie of the University of Montpellier in 1981 where he established a research group working in the fields of the synthesis and modification of zeolites and their uses in catalysis. He addresses several processes dealing with refining and petrochemistry, in close collaboration with major industrial groups.From 1994 to 2002 he headed the laboratory of Catalytic Materials and Catalysis in Organic Chemistry (a join CNRS/University research unit), which activities cover the synthesis of porous materials and nano-particles by self-assembly, heterogeneous catalysis applied to refining, fine chemicals production, environment protection and remediation, biocatalysis, theoretical chemistry modeling, immobilization and delivery of drugs. In 2007 he becomes the director of the Institute for Molecular and Materials Chemistry, an Institution dedicated to, research and education gathering 230 staff and 200 PhD students and post-docs, created under the auspices of the French Ministery of Research and CNRS to reinforce and strengthen chemistry on the site of Montpellier.
Fran？ois Fajula is 65 years old. He is CNRS Emeritus Research Director. He is the author of 270 scientific papers and 35 original patents, several of which were brought to the industrial stage. From 2004 to 2010 he was the president of the International Zeolite Association (IZA). He has received several awards, such as the CNRS Bronze Medal, the AIChE Award, the Award of the French Chemical Society and, more recently in 2013, the Award of the International Zeolite Association. This Award gives to Fran？ois Fajula the title of Ambassador of IZA for a period of three years.
Contacts: DNL1208 Shasha He(89870)