In-line particle characterization

US10119900B2 · kind B2 · utility

Assignee

• NEW YORK UNIVERSITY · US

Inventors

• Chen Wang
• Hagay Shpaisman · Highland Park, US
• Andrew D. HOLLINGSWORTH · Princeton, US
• David G. Grier · New York, US

Key dates

• Filing date: Jun 24, 2015
• Grant date: Nov 6, 2018
• Expiry date: Jun 24, 2035

Classification

• Technology area (CPC G): Physics
• CPC primary: G06V2201/12
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

Holographic video microscopy yields fast and accurate measurements of the size and refractive index of individual colloidal particles. Particle-resolved characterization offers useful insights into the progress of colloidal synthesis without relying on models for the distributions of particle sizes and properties, and can be performed rapidly enough to provide feedback for process control. The measured increase in the most probable radius over the course of the reaction is consistent with the LaMer model for colloidal growth. Uniformity in the measured refractive index suggests that the spheres grow with uniform density. The joint distribution of size and refractive index provides evidence for a low rate of nucleation proceeding after the initial nucleation event. The same analysis reveals that these PDMS particles shrink by compactification in the first few days after their synthesis.