Probing mechanisms of novel templated synthesis.
EMSL Project ID
2562
Abstract
Since the novel templating agents are used in the research it is not surprising that new templating mechanism and new nanostructures are involved. In the template-direct synthesis, polymers or surfactant molecules organize themselves in different type of micelle structures which guide the formation of the mesoporous oxides via electrostatic and hydrogen-bonding interactions. Thus it is important to determine the micelle structures of or novel templates. Our new micellar structures can be formed by systematically varying the ratio of rigid to soft polymer chain lengths. We expect that the final pore size of the materials will be more closely related to the size of the rigid polymer chains, yielding the final products with larger pores. Our previous studies have shown that the nano- or meso-architectures which evolve in templated growth of porous ceramic phases can be probed by a variety of 13C NMR NMR techniques. We have pioneered in study of surfactant ordering at the interfaces using chemical shift, relaxation time measurements, and two-dimensional proton wide line separation (2D WISE) 1H – 13C NMR. The information on the conformation and dynamics of templated agents in as-synthesized ceramic materials can be obtained from the NMR studies, providing insight into how the templated polymer or supramolecules are evolved into the final mesophase ceramics. Since the template synthesis of mesoporous material involves the interaction between the inorganic precursor such as hydrolyzed TEOS and the organized micellar solution of templating agents, the interfacial bonding can be probed using both 13C and 29Si NMR techniques. Therefore, the templating mechanism of our novel templates can be totally elucidated using modern spectroscopic techniques including both SANS and NMR in combination with N2 adsorption, TEM and x-ray diffraction. We are requesting both the 300 and 500 MHz NMR spectrometers for this proposed study.
Project Details
Project type
Capability Research
Start Date
2002-10-01
End Date
2003-09-16
Status
Closed
Released Data Link
Team
Principal Investigator