structures, yet remain underutilized synthons in the growth of nanomaterials. In view of the above, future research needs in the chemical synthesis of nanophase materials are:

• New synthesis strategies for a directed (chemically driven) synthesis

• Better control over chemical and structural homogeneity, the latter feature being crucial for nanocomposites

• Combinatorial methods for the exploration of complete thermodynamic space

• New chemical principles for designed texture, microstructure, and size-tuning

• Computational methods applicable to complex systems

• Development of precursor systems for nonstoichiomet-ric compounds and doped materials

• Isolation and characterization of high-nuclearity molecular clusters (e.g., partially hydrolyzed species isolated from the sol-gel process), which can reveal the intermediate stages of the molecule-to-material conversion process

• Laboratory validation of discrete steps in the synthetic pathways and a knowledge base to guide the material scientist from the initial conception of a chemical synthesis to a reasonable strategy

• Up-scaling of laboratory procedures by development of commercially viable production methods.

The search for new materials is subject to rationales for providing chemical composition and structures, which constitute the feedback for new synthetic approaches and composition-structure-property relationships. This requires identification of new materials by both experimental (e.g., combinatorial materials synthesis) and computational (energy landscapes of different chemical systems to identify kinetically stable structures) methods. Finally, serious efforts at a complete characterization and proved improvement in the properties of the synthesized nanomaterial is needed from the chemistry community, especially to overcome mindsets and biases about molecular chemistry routes, for instance, the general (mis)conception that a multicompo-nent molecular precursor would definitely dissociate under experimental conditions to produce a mixture of individual components.

0 0

Post a comment