Technologies and Capabilities

Nanocrystalline materials consist of ceramic materials in powder form, with particle sizes measured in nanometers - billionths of a meter. The near atomic sizes of these particles, combined with the dynamic properties of surface atoms, mean they can be used to alter and enhance the performance of other materials. These capabilities enable Nanophase to produce materials with chemical, mechanical, electrical and optical behavior that go beyond the capability of the original material.

We use a variety of technologies to achieve these results.

PVS (Physical Vapor Synthesis)

The first nanopowder manufacturing process developed and scaled-up at Nanophase Technologies Corporation was the patented Physical Vapor Synthesis (PVS) Process. In this process, arc energy is first applied to a solid precursor (typically metal) in order to generate a vapor at high temperature. A reactant gas is then added to the vapor, which is then cooled at a controlled rate and condenses to form nanoparticles. The nanomaterials produced by the PVS process consist of discrete, fully-dense particles of defined crystallinity. This method typically produces particles with average sizes ranging from 8-75 nm. Nanophase Technologies uses the PVS process in the commercial scale production of, NanoGard^® Zinc Oxide and NanoTek^® Aluminum Oxide. In addition, this process has been used to generate additional materials such as a variety of doped zinc oxides, selected rare earth and transition metal oxides, and transparent conductive oxides such as antimony-tin oxide and indium-tin oxide.

NAS (NanoArc^TM Synthesis)

The second-generation nanopowder manufacturing process developed at Nanophase Technologies is the patent-pending NanoArc^TM Synthesis (NAS) Process. Like the PVS process, the NAS process uses arc energy to produce nanoparticles. The NAS process, however, is capable of using a wide variety precursor formats and chemical compositions, thereby greatly expanding the number of materials that can be manufactured as nanopowders at commercial scale.

The nanomaterials produced by the NAS process consist of discrete, fully-dense particles of defined crystallinity. This method has been used to produce particles with average sizes ranging from 7-45 nm.

An enhanced capability of the NAS process is its ability to process complex multi-component materials. This process has demonstrated the ability to produce homogeneous mixed metal oxide nanopowders where the component materials form solid solutions with well-defined single crystalline phases. Nanocrystalline metal oxides having up to four metallic elements have been successfully produced.

The NAS process has the capability to produce a wide variety of single-phase pure and mixed rare earth oxides, as well as pure and mixed transition metal oxides and main group metal oxides. The materials produced by this process have application in ultrafine polishing and chemical-mechanical planarization (CMP), catalysis, fuel cells, electronic materials, and advanced imaging.

A unique capability of the NAS process is in situ particle surface modification. This capability has been used to produce materials, at commercial volumes, which can be processed to yield extremely stable dispersions, such as NanoArc^TM Cerium Oxide SG, which has found particular utility in ultrafine polishing and chemical-mechanical planarization (CMP) applications.

Nanoparticle Coatings - Discrete Particle Encapsulation

Nanophase Technologies Corporation has developed processes to coat the surface of its nanoparticles with a thin polymeric shell that enables compatibility of the particles with a wide variety of fluids, resins and polymers. This patented technology, called Discrete Particle Encapsulation, ensures that the appropriate surface coating completely surrounds each individual particle, where the chemistry of the coating is selected to provide the characteristics required for compatibility. In this way, the nanoparticles retain their original chemical and physical properties, but the coating can be tailored for wide variety of applications and environments, ranging from extremely non-polar (hydrophobic) to very polar systems. DPE allows Nanophase to supply nanoparticles in a dry powder form that is ready to be introduced into a customer's application or formulation.

Nanoparticle Dispersions

In many cases, the successful application of nanoparticles in a particular application depends upon the ability to properly disperse the nanoparticles into a fluid. Application areas as diverse as cosmetics, coatings, polishing and catalysis all require that the particles are initially well dispersed and that the particles stay well dispersed (i.e. do not aggregate or "crash out" in the application environment) in order to exhibit their full activity. To meet his need, Nanophase has developed technology to permit the dispersion of its nanoparticles in water and a variety of polar and non-polar organic fluids. This allows Nanophase to supply concentrated, ready-to-use nanoparticle dispersions, eliminating the need for customers to disperse the nanoparticles themselves. This capability proves particularly attractive to customers who lack the equipment to prepare dispersions or wish to avoid handling dry powders.

Aqueous Dispersions
Oftentimes, the electrostatic requirements for aqueous dispersion stability can be directly engineered at the particle surface using the PVS or NAS processes. In other cases, depending upon the application pH requirements, a compatible dispersant chemistry is selected which allows the particles to maintain a high electrostatic charge even after the natural isoelectric point of the particles is crossed. Under these conditions, the particles repel one another and do not aggregate. This dispersant chemistry is used in conjunction with specialized processing to produce highly stable, concentrated aqueous dispersions of the nanoparticles. In addition, once the particles are well dispersed in water, a variety of further processing options can be accessed: additional complimentary chemistries can be added, the pH can be altered to suit a particular application, or the particle size distribution can be tailored to meet a specific requirement.

We welcome questions on the format in which our products can disperse. Contact us to discuss your needs.

Organic Dispersions
In polar and non-polar organic fluids, nonionic steric stabilizers are employed. These dispersants prevent the particles from forming larger aggregates through repulsive forces extending from the particle-continuous phase interface. Using this technology, Nanophase can prepare stable dispersions of the nanoparticles in most common organic solvents and resin systems.