(b) Bottom-up approach
precipitation, hydrothermal synthesis, template assisted sol-gel, electrodeposition etc, are some of the well- known bottom–up techniques reported for the preparation of luminescent nanoparticals.
Explanation: colloidal dispersion is an example of bottom up approach in the synthesis of nano particles. attrition, milling and etching are typical top down methods.
A bottom up synthesis method implies that the nanostructures are synthesized onto the substrate by stacking atoms onto each other, which gives rise to crystal planes, crystal planes further stack onto each other, resulting in the synthesis of the nanostructures.
What are the approaches to make nanomaterials?
The popular techniques of bottom-up approaches include chemical vapor deposition (CVD), chemical vapor condensation (CVC), plasma or flame spraying synthesis, laser pyrolysis, precipitation, reduction, sol-gel, solvothermal, matrix-mediated (template-assisted) processing, self-assembly, and so on.
Bottom-up engineering approach
The bottom-up approach is based on the principle of molecular self-assembly. This phenomenon is defined as a spontaneous organization of molecules under near thermodynamic equilibrium conditions to form stable structures.
Generalization is a bottom-up approach in which two lower level entities combine to form a higher level entity. In generalization, the higher level entity can also combine with other lower level entity to make further higher level entity.
2. Which of the following is an example of bottom-up approach for the preparation of nanomaterials? Explanation: Dip pen nanolithography is an example of bottom-down approach for the preparation of nanomaterials.
In bottom-up investing concentration is on business-by-business or sector-by-sector fundamentals. This analysis seeks to identify profitable opportunities through the idiosyncrasies of a company’s attributes and its valuations in comparison to the market.