SURFACE ENERGY MODIFIED PARTICLES, METHOD OF MAKING, AND USE THEREOF

摘要

An apparatus and a process for modifying the surface energy of particles using a reactive gas or reactive energetic species generated in an excited and/or unstable gas stream is provided. The apparatus and process incorporates a process container, a portion of which is movable and having a shape in which the particles are tumbled during exposure to the energetic species. The resulting surface treatment allows the energy modified particles to be more easily dispersed in a liquid medium with a reduction in the occurrence of particle agglomeration or flocculation.

主权项

1. A process for modifying the surface energy of particles, the process comprising:
providing a low pressure system having at least one vacuum chamber, a vacuum pump system, and, optionally, one or more power sources; placing a predetermined amount of particles into a process container that has a center axis with at least a portion of the process container capable of being rotated, moved, or vibrated, such that the particles are stirred or moved; the process container either being the vacuum chamber or a separate container located in and exposed to the vacuum chamber; placing a filter in a position capable of maintaining the particles in the process container; causing the at least a portion of the process container to rotate, move, or vibrate; reducing pressure in the vacuum chamber using the vacuum pump system to an initial pressure that is below atmospheric pressure; allowing at least one primary gas stream to enter the vacuum chamber; the at least one primary gas stream having a variable or pulsed flow rate, wherein the at least one primary gas stream comprises one or more reactive gases or precursors to reactive energetic species; adjusting the pressure in the low pressure system using the vacuum pump system, changing the flow rate of the primary gas stream, or a combination thereof to establish a working pressure that is either the same as or different from the initial pressure; optionally, using the one or more power sources to supply energy to form a plasma in the gas stream; exposing the surface of the particles to either the one or more reactive gases or the reactive energetic species generated by the interaction of the plasma with the primary gas stream, thereby, forming energy modified particles having a surface treatment; venting the vacuum chamber; and collecting the energy modified particles.