Nanopowders & Nanoparticles

Nanopowders are powders consisting of nanoparticles: particles with all dimensions less than 100nm. They are used in a variety of material fabrication processes, and many of our materials are available in this form. Nanoparticles can exhibit a variety of morphologies, including spheres, rods, fibers, cups, and stars. Nanoparticles can even be porous, as in the case of mesoporous silica nanoparticles. Materials sold as nanopowders typically contain particles with some degree of variation in morphology or size while still falling within the 1-100nm range. Nanoparticles with specific, uniform morphologies are often sold under a name that characterizes this morphology, and single-crystal nanomaterials are typically referred to as nanocrystals.

Nanoparticle Suspensions

Nanoparticles can be provided as suspensions in various carrier liquids. Nanofluids are generally defined as suspended nanoparticles in solution either using surfactant or surface charge technology. Nanoparticle inks are suspensions of nanoparticles in dense liquid media such as ethylene glycol. These inks are finding applications in printed electronics, photovoltaics, battery technologies and other renewable energy solutions.

Surface Functionalized Nanomaterials

Surface functionalized materials such as dodecanethiol-functionalized gold nanoparticles have controlled surface chemistries which can provide novel methods to change the adhesion (wetting) properties of the particles, re-order their interfacial region, or enhance the dispersion properties of the nanopowder in polymers, plastics and coatings for improved magnetic, fluorescent, dielectric, and catalytic properties. Surface functionalized nanoparticles have particular application in LEDs, drug delivery systems, sensors and electronics.

Nanowires

Nanowires are nanomaterials with length-to-width ratios greater than 1000 and diameters on the order of nanometers. Common nanowires may be composed of pure metals such as platinum or gold, semiconducting elements and compounds such as silicon and gallium nitride, or insulating materials such as silicon dioxide. Additionally, moleular nanowires are nanowires composed of repeating molecular units; DNA can be considered an organic nanowire. Nanowires can be produced using suspension techniques, vapor-liquid-solid growth (VLS), or solution-phase synthesis. Most applications for nanowires remain experimental, but ultimately these materials may be used in electronics devices, including in next-generation computing devices and sophisticated chemical sensors.

Nanofoils

Nanofoils (or nano-foils) are ultra thin foils as thin as only 20 nm up to 1000 nm, 1 micron, 2 micron, and up to a few microns thick. Nanofoil can also be plated or produced on a substrate with a parting agent to permit removal by floating and can then be mounted on frames.

Nanorods

Nanorods are nanoparticles with rod-like morphology, and each of their dimensions falls within the range of 1-100nm. Most commonly, they are about 3-5 times as long as they are wide, though this can vary with material and synthesis conditions. Nanorods are synthesized from metals or semiconducting compounds.

Nanotubes

Nanotubes are materials which exhibit a cylindrical nanostructure. The first nanotubes described were carbon nanotubes, cylindrical tubes of carbon that are members of the fullerene structural family. Carbon nanotubes have a number of unusual properties including high strength, and have a wide variety of applications. Other nanotubes now produced include silicon nanotubes, which have potential applications in hydrogen storage, battery technology, and boron nitride nanotubes, which show promise in aerospace applications due to their strength and radiation-shielding properties.

Carbon-based Nanomaterials

In the past decade, carbon-based nanomaterials have become increasingly important in research, industrial and commercial applications. Graphene, a flat one-atom thick sheet of carbon atoms densely packed in a honeycomb crystal lattice structure, is a unique material that exhibits extremely high strength, electrical conductivity and is one of the most opaque materials known. The discovery of graphene has greatly expanded the possibilities for improvement and development of advanced technologies, from microelectronics and nanomedicine to spintronics-based computing. Research into graphene and graphene oxide have led scientists to synthesize other two-dimensional materials like hexagonal boron nitride (hBN), molybdenum diselenide (MoSe2), molybdenum disulfide (MoS2), tungsten diselenide, (WSe2) tungsten disulfide (WS2), and others which may have the ability to outperform graphene for applications such as photovoltaic panels.

Fullerenes, spherical cage-like carbon structures known as "buckeyballs", have found applications in lithography and medicine. Carbon nanotubes are among the stiffest and strongest fibers known to man and have unique electrical properties. When used as reinforcement fibers, carbon nanotubes can improve the quality and properties of metal, polymers and ceramics. Carbon nanotubes are found in flat screen displays, needles for scanning probe microscopes, brushes for commercial electric motors, and in sensing devices.

Carbon nanotubes are extraordinary materials which come in several variations and exhibit highly unique properties. These materials are effectively rolled tubes of graphene, and contain only sp2 bonds, which are even stronger than the sp3 found in diamond. These bonds, arranged in the cage like structure of the nanotube, give these unique materials their considerable strength. Currently they are widely used to enhance the strength of structural materials, as tips for atomic force microscope probes, and as scaffolds in tissue engineering, but dozens of additional applications are areas of active research.

Quantum Dots

Quantum dots are crystalline semiconductor materials with diameters ranging from 2-10 nanometers, making them small enough to exhibit quantum mechanical properties. Specifically, in quantum dots the crystal’s diameter is smaller than the size of the material’s exciton Bohr radius, leading to quantum confinement. The materials therefore exhibit electronic and optical properties that are tunable based on manipulation of the precise particle size. One common phenomena seen in quantum dots is fluorescence, which has been exploited in light-emitting devices such as LEDs and diode lasers. Additionally, quantum dots are being investigated as labeling agents for medical imaging, light absorbing materials for solar cells, and quibits in quantum computing.

Fluorescence

Fluorescent nanoparticles are promising tools for technical applications in optical data storage, renewable energy solutions and biomedical fields. Quantum dots, for example, can be tuned to emit specific wavelengths of light through careful control of their particle size. Numerous biomedical assays utilize fluorescent nanoparticles as tools to bind biomolecules for diagnostics, analytics, and biochemical studies. Immunoassays, microarrays, intracellular sensing and medical diagnostics are areas that have found particularly beneficial uses of fluorescent nanoparticles.

Magnetism

Magnetic nanoparticles such as iron oxide are nanoparticles that exhibit magnetic properties and can be manipulated by a magnetic field. Studies in the application of these magnetic nanoparticles have led to new research areas in medicine, renewable energy and computing.

Semiconductivity

Semiconductor materials have long been used in the electronic and computing industry. Nanoscale semiconductors are now being implemented into circuit components and devices to produce next generation products and processes. Nanowires are used by to produce a new generation of transistors and antennas. In addition to this, a host of research is ongoing in the uses of nanowires as a means of energy harvesting and storage.

Porosity

Nanoporous nanostructures increase surface area of a given 2D nanoparticle and in turn can be useful for membrane applications. Controlling pore sizes in nanoparticle production is a key aspect to nanoporous materials and their uses. This research holds promising applications for electronic devices.

A wide range of methods are used to synthesize nanomaterials and can be categorized as either one of two general approaches, top-down synthesis or bottom-up synthesis. Top-down synthesis methods begin with macroscopic structures or materials that undergo processing to form nanostructured materials. Bottom-up synthesis of nanomaterials starts with atoms or small molecules that can undergo self-assembly to form new nanostructures. Common examples of the bottom-up method include quantum dot formation during epitaxial growth and nanoparticle formation from colloidal dispersion.

SNT Group can "grow" larger than typical particle sizes for materials for various purposes; for example, to create particle distributions in the 20 to 70 micron range for materials that are naturally produced in the 2 to 8 micron range. This allows our customers to use them in plasma spray guns and in other deposition technologies that can be blocked by particles that are either too small or too large for the delivery system. Other materials processing techniques include ink jet, spin coating, screen printing, slot-die, and doctor blading. We can also achieve very high surface area ranges up to 130 square meters per gram for products used in environmental groundwater remediation, electronics, batteries, dielectric and magnetic and fuel cell applications, and optical, imaging and catalyst functions.

Our expertise in formulation engineering enables us to produce nanomaterials tailored to customer specifications at commercial-scale volumes up to multi-ton batches. SNT Group physical morphology capabilities include aerosol, thermal and sol-gel methods, attrition, ball and jet milling, atomization, particle growth by fusion and sintering, and co-precipitation and screening classification. Analysis and certification include particle distribution by laser diffraction, BET surface area analysis, phase analysis by X-ray diffraction and SEM.