Zhang B.J.,NBD Nanotechnologies, Inc. |
Zhang B.J.,University of Nevada, Las Vegas |
Kim K.J.,University of Nevada, Las Vegas
International Journal of Heat and Mass Transfer | Year: 2014
In this study, we have observed substantial pool boiling heat transfer augmentation by creating one-dimensionally grown Alumina Nano Porous Surface (1-D ANPS). Pre-organized numerous nano pores have structural uniqueness such as enlarged surface area, increase in active nucleation sites, and liquid thin film evaporation at vapor-liquid menisci of the pore mouth. At the same time, the surface wetting of a cylindrical heater is modified with a hydrophobic Self-Assembled Monolayer (SAM) coating. Enhanced water contact angle of the 1-D ANPS yields substantial active nucleation site increase by preventing liquid impregnation into nano pores, which play a role of trapping non-condensible gas. The combination of structural uniqueness of the 1-D ANPS and surface wettability modification achieves significant heat transfer coefficient (HTC) enhancement in the nucleate pool boiling regime. Also, HTC improvement is closely related to bubble interactions on the cylindrical heating surface while they are moving along the periphery. For a hydrophobic surface, bubble sweeps along the heater periphery and efficiently removes adjacent premature bubbles. It leads to reduced waiting time. Enlarged bubbles carry more heat from the surface and yield huge internal/external convection. In order examine bubble motions, an analytical model and high speed camera were used. © 2014 Elsevier Ltd. All rights reserved. Source
NBD Nanotechnologies, Inc. | Date: 2015-09-24
Fluorinated polyhedral oligomeric silsesquioxane (F-POSS) copolymers and terpolymers useful in the field of coatings for enhancing performance of materials surfaces. Also disclosed are methods for making such copolymers and terpolymers.
Agency: Department of Agriculture | Branch: | Program: SBIR | Phase: Phase II | Award Amount: 500.00K | Year: 2015
Fog harvesting from fog nets has been intensively investigated to utilize untapped fresh water resources. Atmospheric water like fog constitutes approximately 0.04% of the earth's fresh water. If fog is harnessed appropriately, it has a huge potential to alleviate fresh water shortages due to depleting watershed and groundwater resources NBD Nanotechnologies, Inc. is proposing a research program to commercialize a proprietary surface coating for fog net applications to exploit underused fresh water resources in fog-laden areas. The proposed coating consists of a proprietary blend of superhydrophobic coatings to which NBD has exclusive licensing rights, and uses a one-step dip process that is very amenable for mass-manufacturing and scale up. Also, an embedded drainage design and multi-layered fog nets can promote significant enhancement of water collection from the fog nets. During USDA SBIR Phase I, NBD has shown that by modifying the surface texture and chemistry of a fog net with a superhydrophobic coating, and optimizing the mesh structure, the fog collection efficiency of a system can be enhanced five-fold.Fog nets with enhanced water collection efficiency would provide an ecofriendly and low-cost solution towards reducing the strain on the fresh water supplies in drought-affected areas as well as providing an effective method of delivering water for onsite crop irrigation. If successfully implemented on a commercial scale, the enhanced fog harvesting abilities of the proposed fog nets will reduce the strain on watershed resources in drought afflicted regions, and provide a valuable source of fresh water in isolated rural communities.
NBD Nanotechnologies, Inc. | Date: 2015-10-07
The present disclosure relates, in exemplary embodiments, to compositions of matter comprising synthetic blends of at least two feedstocks that produce a distribution of fluorinated polyhedral oligomeric silsesquioxane molecule structures. The present disclosure also relates, in exemplary embodiments, to methods of making such synthetic blends.
Agency: Department of Agriculture | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 100.00K | Year: 2014
Large areas across the United States and around the world are afflicted by drought, a condition that inflicts damage to local economies and particularly to agriculture. While some communities are turning to expensive energy-intensive processes such as desalination and long distance transport to address water shortages, NBD Nanotechnologies, Inc. is working to reduce stress on watershed resources by tapping into an underutilized fresh water resource - fog. Approximately 0.04% of the earth & #39;s fresh water is in the form of fog. In areas where fog droplets are heavy and the fog is thick, it can be collected by means of fog nets - simple systems with both minimal technology requirements and capital expenses. Fog harvesting has been so effective in some locations, that some developing communities are able to depend solely on fog nets to supply water for agriculture, cooking, and washing. Positive economic effects due to fog harvesting have already been observed in local populations along the arid coastal regions of Chile, Peru, and Nepal, among others. To date, fog nets are effective for harvesting water only in coastal regions where wind speeds are sufficiently high to support large fog droplets. In areas where fog is abundant but the size of the droplets is smaller, such as along the west coast of California, conventional polypropylene fog nets do not efficiently collect water. NBD Nanotechnologies, Inc. aims to optimize the surface chemistry and geometrical properties of the fog nets in order to harvest fog droplets too small for conventional netting. If successful, the technology would allow water to be harvested along the arid coastal regions of California, among others, to be used on site for irrigation or transported to drier regions. The proposed technology has already been proven by academic partners at laboratory scale. During Phase I of this project, NBD Nanotechnologies, Inc. will improve the chemistry of the coatings and scale up the manufacturing of the fog net prototypes. These prototypes will be tested under actual operating conditions in outdoor environments. Furthermore, NBD Nanotechnologies, Inc. will test the quality of the water collected as well as investigate the durability and wear performance of the coated fog nets over time and under accelerated wear conditions. If successful, Phase II of this project will focus on further scale up and marketing issues. The initial target market for the advanced fog net coatings will be vineyard businesses where a commercial size fog net would be capable of continuously irrigating six vine plants in full foliage. Through this work, NBD Nanotechnologies, Inc. hopes to create a profitable business, provide an inexpensive technology to harvest fog water, reduce the stress on existing watershed resources, increase job opportunities in the clean technology sector, and raise awareness of fog as a potential water source, particularly in California.