Microreactor-Assisted Nanomaterial Deposition (MAND) is a promising technology that synthesizes reactive fluxes and nanomaterials to deposit nanostructured materials at the point of use. MAND offers precise control over reaction, organization, and transformation processes to manufacture nanostructured materials with distinct morphologies, structures, and properties. In synthesis, microreactor technology offers large surface-area-to-volume ratios within microchannel structures to accelerate heat and mass transport. This accelerated transport allows for rapid changes in reaction temperatures and concentrations, leading to more uniform heating and mixing in the deposition process. The possibility of synthesizing nanomaterials in the required volumes at the point of application eliminates the need to store and transport potentially hazardous materials. Further, MAND provides new opportunities for tailoring novel nanostructures and nano-shaped features, opening the opportunity to assemble unique nanostructures and nanostructured thin films. MAND processes control the heat transfer, mass transfer, and reaction kinetics using well-defined microstructures of the active unit reactor cell that can be replicated at larger scales to produce higher chemical production volumes. This critical feature opens a promising avenue in developing scalable nanomanufacturing. This paper reviews advances in microreactor-assisted nanomaterial deposition of nanostructured materials for solar photovoltaics. The discussions review the use of microreactors to tailor the reacting flux, transporting to substrate surfaces via controlling process parameters such as flow rates, pH of the precursor solutions, and seed layers on the formation and/or transformation of intermediary reactive molecules, nanoclusters, nanoparticles, and structured assemblies. In the end, the review discusses the use of an industrial scale MAND to apply anti-reflective and anti-soiling coatings on the solar modules in the field and details future outlooks of MAND reactors.
Overcoming the rise in local deposit resistance during electrophoretic deposition via suspension replenishing
Nanomaterials have unique properties, functionalities, and excellent performance, and as a result have gained significant interest across disciplines and industries. However, currently, there is a lack of techniques that can assemble as-synthesized nanomaterials in a scalable manner. Electrophoretic deposition (EPD) is a promising method for the scalable assembly of colloidally stable nanomaterials into thick films and arrays. In EPD, an electric field is used to assemble charged colloidal particles onto an oppositely charged substrate. However, in constant voltage EPD the deposition rate decreases with increasing deposition time, which has been attributed in part to the fact that the electric field in the suspension decreases with time. This decreasing electric field has been attributed to two probable causes, (i) increased resistance of the particle film and/or (ii) the growth of an ion-depletion region at the substrate. Here, to increase EPD yield and scalability we sought to distinguish between these two effects and found that the growth of the ion-depletion region plays the most significant role in the increase of the deposit resistance. Here, we also demonstrate a method to maintain constant deposit resistance in EPD by periodic replenishing of suspension, thereby improving EPD’s scalability.
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- Award ID(s):
- 1727930
- NSF-PAR ID:
- 10432342
- Date Published:
- Journal Name:
- Frontiers in Chemistry
- Volume:
- 10
- ISSN:
- 2296-2646
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Abstract Microreactor-Assisted Nanomaterial Deposition (MAND) process offers unique capabilities in achieving large size and shape control levels while providing a more rapid path for scaling via process intensification for nanomaterial production. This review highlights the application of continuous flow microreactors to synthesize, assemble, transform, and deposit nanostructured materials for Solar Photovoltaics, the capabilities of MAND in the field, and the potential outlook of MAND Graphical abstract -
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.3389/fchem.2022.970407
