936 results about "Zeta potential" patented technology

The present invention relates to nanoparticles comprising a biodegradable polymer, preferably the vinyl methyl ether and maleic anhydride (PVM / MA) copolymer, and a polyethylene glycol or derivatives thereof. These nanoparticles are easy to produce and provide excellent bioadhesion, size and zeta potential characteristics making them suitable for the administration of active molecules. The selection of the type of polyethylene glycol used in their production allows suitably modulating the characteristics of these nanoparticles, which can be advantageously used according to the type of drug to be carried and / or the method of administration of the pharmaceutical formulation. pegylation is carried out by simple incubation for a short time period of the two macromolecules in question, without needing to have to resort to the use of organic solvents with high toxicity or long and laborious organic synthesis processes. Furthermore, the pegylation process can be associated to the process of encapsulating the biologically active molecule.

The present invention is directed to a method, system, and apparatus for applying megasonic energy to the surface of a workpiece for the removal of contaminants. A nozzle dispenses a stream of deionized water or other cleaning fluid at a radial position on the surface. A stepping motor moves the arm over the surface, in a step-wise manner, allowing megasonic energy to be applied in a uniform manner. The workpiece is rotated at low speeds to provide a more uniform application. Chemical solutions may optionally be added to dissolve contaminants or change the Zeta potential of the contaminants to make particles easier to detach and suspend. A high-RPM dry spin cycle further removes cleaning fluid and suspended contaminants, preventing them from reattaching. The present invention is compatible with numerous types of workpieces including 12'' semiconductor wafers.

Provided is a toner manufactured in an aqueous solvent, whereby a satisfactory image density can be obtained and the toner laid-on level on a recording medium can be reduced with a normal added concentration of pigment without adding a large quantity of pigment to the toner. The toner is manufactured in an aqueous medium by the suspension polymerization or dissolution suspension method and contains a binder resin, a pigment and an azo compound. The azo compound is a specific azo compound, and the absolute value of the difference in zeta potential between the binder resin and the azo compound is 25 mV or less.

The process of heavy metals removal from the waste water using silica dispersion without mixing silica dispersion with the waste water. This is achieved due to the membrane device where silica dispersion and waste water stream are separated by membrane with pore sizes smaller that size of the silica particles. The process is organized as counter-flow, which means that silica dispersion and waste water flow in the opposite directions. This provides the maximum utilization of the adsorption capacity corresponding to the adsorbent being in equilibrium with the high initial concentration of the contaminant in distinction from the low utilization when adsorbent works in equilibrium with the low output concentration. In the particular instance the membrane device comprises a lumen of a bundle of hollow fibers with silica dispersion flowing either inside or outside of the fibers and wastewater flowing on the opposite side of the fiber membrane. This process eliminates step of separating silica from the wastewater. It opens way to use colloidal silica as adsorbent with highly developed surface area. Continuous monitoring of the silica particles zeta potential yields information for preventing colloidal silica solidification within the device. Solidification of the colloidal silica afterwards solves problem of untreated residual discharge.