Patent Application
20240270593
The disclosure of the present patent application relates to nanostructures, and particularly to a method for synthesizing zinc oxide nanoroses.
In recent decades, research into the properties of nanoparticles has led to significant advances in many fields of technology. The properties of nanoparticles may be greatly affected, not only by the size of the particles, but also by the elemental composition, the nature of any substrate to which they are attached, the morphology or structural shape of the nanoparticles, and many other factors.
In dentistry, for example, nanoparticles have been found useful for improving dental implant procedures, including acting as a carrier for drugs, for increasing bonding to bone, for helping to prevent the subsequent development of dental caries, etc. The nanoparticles used in this field have included, e.g., gold, silver, zinc oxide, titanium, silicon, and others. Zinc oxide, for example, is known to exhibit antibacterial properties. It has also been found that the strength of antibacterial protection provided by zinc oxide nanoparticles is affected by the morphology or structural shape of the nanoparticles. Hence, there has been a significant amount of research in recent years to develop stable zinc oxide nanoparticles in a variety of shapes. Thus, a method for synthesizing zinc oxide nanoroses solving the aforementioned problems is desired.
The method for synthesizing zinc oxide nanoroses is a green, fast, and cost-effective approach for the growth of ZnO nanoroses in which a sheet of vertically aligned and interconnected sheet of ZnO nanospheres are grown on a titanium buffer layer coated on a silicon substrate, the nanospheres mimicking a rose-like structure. According to the method, a film of titanium is first deposited on a Si/SiO2 substrate by an e-beam evaporation method. Then, the titanium film coated substrate is suspended upside down in a solution of zinc nitrate (0.011 M-0.055M) in an aqueous solution of hexamethylenetetramine (0.011 M-0.055M) and heated to 50-100° C. with vigorous stirring for 60-180 min. The resulting ZnO nanoroses are washed with de-ionized water and air-dried for 12-24 hours. The ZnO nanoroses are suitable for use for various device applications in electronics and biomedical systems.
These and other features of the present subject matter will become readily apparent upon further review of the following specification.
Similar reference characters denote corresponding features consistently throughout the attached drawings.
The method for synthesizing zinc oxide nanoroses is a green, fast, and cost-effective approach for the growth of ZnO nanoroses in which a sheet of vertically aligned and interconnected sheet of ZnO nanospheres are grown on a titanium buffer layer coated on a silicon substrate, the nanospheres mimicking a rose-like structure. According to the method, a film of titanium is first deposited on a Si/SiO2 substrate by an e-beam evaporation method. Then, the titanium film coated substrate is suspended upside down in a solution of zinc nitrate (0.011 M-0.055M) in an aqueous solution of hexamethylenetetramine (0.011 M-0.055M) and heated to 50-100° C. with vigorous stirring for 60-180 min. The resulting ZnO nanoroses are washed with de-ionized water and air-dried for 12-24 hours. The ZnO nanoroses are suitable for use for various device applications in electronics and in biomedical (dental and orthopedic implants) systems.
The method for synthesizing zinc oxide nanoroses will be better understood with reference to the following examples.
Coating Silicon Substrate with Titanium Film Buffer Layer
Titanium (Ti) films were deposited by electron-beam evaporation technique onto Si/SiO2 (100) substrate by evaporating Ti metal. The films were deposited on Si/SiO2 (100) substrates (area=40×20 mm2), which were oxidized in a furnace for 1-2 hours at 1000° C.-1200° C. and cleaned by rinsing in ultrasonic baths of acetone and methanol prior to the deposition, and then fixed in a single-rotation holder mounted 300 mm above the vapor source. Commercial Ti metal (99.9999%; 3.2 mm diameter×3.2 mm length, purchased from Alfa Aesar) slugs were placed into a crucible as evaporation sources for film deposition. The vacuum chamber was equipped with a turbo-molecular pump, which is horizontally fixed to the chamber, backed by a rotary pump and could produce an ultimate vacuum of 2.1×10−6-7.2×10−7 Torr. A series of Ti films with substrates at room-temperature, 100° C., 200° C., and 300° C. were deposited for 5-60 min at a power of 500-3000 Watt.
The substrate of deposited Ti film on Si/SiO2 substrate was used for the growth of ZnO nanoroses. In this step, the substrate was put upside down in a solution. In this solution, Zinc nitrate (0.011 M-0.055 M) was added to an aqueous solution of hexamethylenetetramine (0.011 M-0.055M) and heated to 50-100° C. with vigorous stirring. Then, the growth of the ZnO was continuous at 50-100° C. for 60-180 min. Finally, as-prepared ZnO nanoroses were thoroughly washed with deionized water, and dried in air at 80-90° C. for 12-24 h before characterization.
In this method, the morphology can be defined as “hierarchical arrangement of nanosheets producing rose-like structures. These nanosheets are arranged hierarchically to form nanorose superstructures with different morphologies than nanospheres. Additionally, the hierarchical ZnO nanoroses originate from the self-assembly of the single-crystalline nanosheets with preferred orientation along the c-axis. In nanospheres, the particles are arrange randomly in a manner so that they can produce solid sphere-like morphology. The nanoroses have a mimic structure of natural roses, thus, are named nanorose.
The structural and morphological properties of the as-grown ZnO nanospheres were confirmed by various analyses. Structural studies confirmed the formation of highly crystalline ZnO with c-axis orientation. Morphological studies showed that the grown ZnO on Ti buffered layered Si substrate are nanospheres in which nanosats are interconnected and vertically aligned, mimicking a rose-like structure. The size of the synthesized nanoroses was measured by FESEM technique. The lateral dimension of the nanoroses ranged from 0.5 microns to 1 micron, and the thickness of the nanosheets ranged from 10 to 20 nm, respectively. These ZnO nanospheres could be useful for biomedical device applications, including dental and orthopedic implants. The presented approach can be applied to the large-scale production of other metal oxide nanostructures.
It is to be understood that the method for synthesizing zinc oxide nanoroses is not limited to the specific embodiments described above, but encompasses any and all embodiments within the scope of the generic language of the following claims enabled by the embodiments described herein, or otherwise shown in the drawings or described above in terms sufficient to enable one of ordinary skill in the art to make and use the claimed subject matter.
