Novel Particle Size Characterization of Coating Pigments: Comparing Acoustic Spectroscopy with Laser Light Scattering and Sedimentation Techniques, 2008 Advanced Coating Fundamentals Symposium

ARE YOU A TAPPI MEMBER? TAPPI members have exclusive, FREE access to technical conference papers and presentations six months after the conference in TAPPI's e-library. The e-Library offers:

• Unlimited access to more than 18,000+ documents
• Fast, robust search engine for fast search results
• Members get FREE access to conference proceedings, TAPPI JOURNAL articles, Paper360º articles, archived Solutions! articles, and much more
• View thousands of technical paper abstracts
• Ability to search by keyword, title, author, events or industry segment

*Technical papers and presentations are available for sale immediately following the conferences before the 6 month embargo period.

Please Note: This document will be available in PDF format in the "My Electronic Documents" link on the home page once your order has been completed. Please make sure you have the latest version of Acrobat Reader. Click on the Acrobat Reader icon to check for the latest version, it’s FREE. To print a hardcopy of a PDF file correctly you must have a postscript printer. If you are not sure if your printer is a postscript printer please refer to your owner’s manual.

Acoustic spectroscopy can be used to characterize the primary or composite particle size distribution of concentrated stable or unstable colloidal dispersions without having to dilute or further prepare the sample. This is illustrated for the case of high solids fine ground calcium carbonate (gcc) paper coating mineral suspensions having two markedly different size distributions. The same samples analyzed using acoustic spectroscopy were also measured using two other well recognized techniques, one based on sedimentation and the other on laser light diffraction. The three methods produced results which were in good agreement with each other for the essentially blocky morphology of gcc. The extended range of measurement of acoustic spectroscopy combined with its flexibility in handling varying solids contents offers new insight in structural phenomena, like depletion flocculation and polymer-bridging, and provides a means of studying the nano-sized populations found in typical fine gcc. The existence of the nano-fraction as a function of solids content is illustrated, and its origins are proposed as partially calcium-crosslinked dispersant polymers and/or composites of sub-grain sized gcc associated with dispersing polymers.