Over the course of this blog, I have delved into many concepts involving nano and microparticles and their potential applications in the field of nanorobotics. Despite the vast range of particulate systems that I have previously mentioned, all come from one of four fundamental structural material types: metals, ceramics, glasses, and polymers. In my final blog post, I will discuss how these materials can be combined to form composite nanoparticulate systems, where the constituent materials retain their identities, each adding to the overall properties of the “composite nanoparticle.”
Composites can be broadly sorted into two categories: Fiber Reinforced Composites and Aggregate Composites. A composite nanoparticle is generally defined as a nanoparticle of composite structure characterized by a core-shell structure, onion-like structure of multiple materials.
In a paper titled Multifunctional Composite Nanoparticles: Magnetic, Luminescent, and Mesoporous, Lin et al. suggest that nanocomposite materials with unique magnetic and luminescence properties have great potential in biological applications such as MRI contrast, drug delivery, cell sorting, and labeling. They focus on the synthesis of mesoporous silica nanoparticles, characterized by their uniquely high surface area, large pore volume, uniform pore size, and low cytotoxicity, combined with gadolinium. Such a composite nanoparticle, they demonstrated, was quite useful as an MRI contrast. They theorize that further modifications with polymer constituents and other metals would give the mesoporous silica nanoparticles even more unique characteristics suited to other biomedical applications.
Researchers agree that leveraging the properties of metals, ceramics, glasses, and polymers at the nanoscale lends nanoparticulate systems a wide variety of applications as catalysts (with huge activity and specificity), metal-semiconductor junctions, drug carriers, optical sensors, and modifiers of polymeric films for packaging.
Composite nanoparticles present a great opportunity to leverage all that we know about nanoparticles of the four fundamental structural material types – metals, ceramics, glasses, and polymers – to create novel nanomaterials and robots to carry out ever more complex and useful tasks.
References:
https://link.springer.com/referenceworkentry/10.1007%2F978-0-387-48998-8_243
https://www.hindawi.com/journals/jchem/2013/536341/