Surface modification methodologies to create diversity in surface chemistry and applications.
A. Roevensa, J. Van Dijcka,b, G. Mustafaa,b, S. Loretoa,M. Dorbecb,B. Prelotc, J. Zajacc, A. Buekenhoudt b, V. Meynena,b
a University Antwerp, Laboratory of Adsorption and Catalysis,Wilrijk, Belgium. Contact:
bFlemish Institute for Technological Research (VITO NV),Unit Separation and Conversion Technology, Mol, Belgium
cInstitut Charles Gerhardt de Montpellier, UMR 5253 CNRS-UM-ENSCM, University of Montpellier, CC1502, Pl E Bataillon, 34095 Montpellier, France
Porous inorganic materials are applied in a wide diversity of applications depending on their structural andphysico-chemical properties. However, although their structure and surface properties can be varied,often extra functionalities are required. For this reason, hybrid organic-inorganic materials are being developed, introducinga wide diversity of chemical interactions,available in organic molecules, to the inorganic matrix. By doing so, not only the type of organic group but also the surface functionalisation mechanism and synthetic conditions create a large matrix of control, adjustable to the specific requirements of the applications.
At the laboratory of adsorption and catalysis (LADCA) different methods are being developed to control the performance and interaction behaviour of materials in applications at all levels of material control (structural and physico-chemical). In view of hybrid organic-inorganic material synthesis, both in-situ and ex-situ methodologies are being developed for silica and metal oxide based materials.
Two different methodologies for surface grafting will be shown (organophosphonic acid surface modification and Grignard modification), each with their particular advantages, levels of control and drawbacks. By applying the appropriate method and modification conditions, unique surface properties can be obtained that allow to tune interactions at the surface and as a result enhance performance of materials in specific applications. The impact of synthesis conditions and mechanisms on the obtained surface properties will be discussed and correlated to their impact on sorption behaviour. Examples will be given from applications such as water purification and solvent filtration, revealing the opportunities introduced by the unique features that designed organic functionalization can add to the top layer of ceramic membranes. The examples will show how new and versatile opportunities in sorption, separation, catalysis and sensors can be created.