Embodiments of the present invention relate to methods for preparing high optical density solutions of nanoparticle, such as nanoplates, silver nanoplates or silver platelet nanoparticles, and to the solutions and substrates prepared by the methods. The process can include the addition of stabilizing agents (e.g., chemical or biological agents bound or otherwise linked to the nanoparticle surface) that stabilize the nanoparticle before, during, and/or after concentration, thereby allowing for the production of a stable, high optical density solution of silver nanoplates. The process can also include increasing the concentration of silver nanoplates within the solution, and thus increasing the solution optical density.

Embodiments of the present invention relate to methods for preparing high optical density solutions of nanoparticle, such as nanoplates, silver nanoplates or silver platelet nanoparticles, and to the solutions and substrates prepared by the methods. The process can include the addition of stabilizing agents (e.g., chemical or biological agents bound or otherwise linked to the nanoparticle surface) that stabilize the nanoparticle before, during, and/or after concentration, thereby allowing for the production of a stable, high optical density solution of silver nanoplates. The process can also include increasing the concentration of silver nanoplates within the solution, and thus increasing the solution optical density.

A process for the preparation of transition metal nanoparticles, the process comprising: (a) providing a mixture comprising one or more salts of one or more transition metals M, one or more complexing agents C, and a solvent system S; (b) optionally adjusting the pH of the mixture provided in (a) to a pH comprised in the range of from 4 to 8; (c) heating the mixture provided in (a) or obtained in (b) for obtaining a colloidal suspension of transition metal nanoparticles; (d) optionally isolating the transition metal nanoparticles obtained in (c), preferably by centrifugation and/or evaporation to dryness of the colloidal suspension obtained in (c) wherein the mixture provided in (a) and heated in (c) or obtained in (b) and heated in (c) does not comprise polyvinyl sulfate and/or polyvinylpyrrolidone.

A process for the preparation of transition metal nanoparticles, the process comprising: (a) providing a mixture comprising one or more salts of one or more transition metals M, one or more complexing agents C, and a solvent system S; (b) optionally adjusting the pH of the mixture provided in (a) to a pH comprised in the range of from 4 to 8; (c) heating the mixture provided in (a) or obtained in (b) for obtaining a colloidal suspension of transition metal nanoparticles; (d) optionally isolating the transition metal nanoparticles obtained in (c), preferably by centrifugation and/or evaporation to dryness of the colloidal suspension obtained in (c) wherein the mixture provided in (a) and heated in (c) or obtained in (b) and heated in (c) does not comprise polyvinyl sulfate and/or polyvinylpyrrolidone.

A method is provided for producing a bonding composition containing copper particles and a second liquid medium. In this production method, the copper particles are produced in a first liquid medium using a wet reduction method, and thus a dispersion of the copper particles is prepared. Subsequently, the first liquid medium in the dispersion is ultimately, finally or eventually replaced with the second liquid medium while the dispersion is kept wet. It is also preferable that the first liquid medium is replaced with another liquid medium one or more times, and the second liquid medium is used in the final replacement. The liquid media are preferably replaced at a temperature of lower than 100° C. The second liquid medium preferably includes one or more of water, alcohol, ketone, ester, ether, and hydrocarbon.

A method is provided for producing a bonding composition containing copper particles and a second liquid medium. In this production method, the copper particles are produced in a first liquid medium using a wet reduction method, and thus a dispersion of the copper particles is prepared. Subsequently, the first liquid medium in the dispersion is ultimately, finally or eventually replaced with the second liquid medium while the dispersion is kept wet. It is also preferable that the first liquid medium is replaced with another liquid medium one or more times, and the second liquid medium is used in the final replacement. The liquid media are preferably replaced at a temperature of lower than 100° C. The second liquid medium preferably includes one or more of water, alcohol, ketone, ester, ether, and hydrocarbon.

A method of forming a super hard polycrystalline construction comprises forming a liquid suspension of a first mass of nano-ceramic particles and a mass of particles or grains of super hard material having an average particle or grain size of 1 or more microns, dispersing the particles or grains in the liquid suspension to form a substantially homogeneous suspension, drying the suspension to form an admix of the nano-ceramic and super hard grains or particles, and forming a pre-sinter assembly comprising the admix. The pre-sinter assembly is then sintered to form a body of polycrystalline super hard material comprising a first fraction of super hard grains and a second fraction, the nano-ceramic particles forming the second fraction.

The super hard grains are spaced along at least a portion of the peripheral surface by one or more nano-ceramic grains, the super hard grains having a greater average grain size than that of the grains in the second fraction which have an average size of less than around 999 nm.

There is provided a formulation containing nanometric single-crystal metallic copper particles, and a method of producing the formulation.

There is provided a formulation containing nanometric single-crystal metallic copper particles, and a method of producing the formulation.

A method of forming a super hard polycrystalline construction comprises forming a liquid suspension of nano-sized super hard particles and particles of super hard material having an average particle or grain size of 1 or more microns, dispersing the particles in the liquid suspension to form a substantially homogeneous suspension which is then dried and sintered to form a body of polycrystalline super hard material comprising a first and second fractions of super hard grains, the nano-sized particles forming the second fraction. The super hard grains in the first fraction are bonded along at least a portion of the peripheral surface(s) thereof to at least a portion of a plurality of nano-sized grains in the second fraction, the grains in the first fraction having a greater average grain size than that of the grains in the second fraction which is less than 999 nm, the average grain size of the first fraction being around 1 micron or more