Visualizing Flocculation and Adsorption Processes in Papermaking Using Fluorescence Microscopy

Abstract

Polymer adsorption characteristics in complex papermaking systems have been elucidated using tagged reagents and the well-established technique of fluorescence microscopy. Interactions between polymers and components of papermaking slurries have been previously well researched, but the theories put forth are usually based on indirect inferences. Moreover, the use of simple model systems often does not permit correlation with real systems. The present study clearly shows that, under shear conditions and time scales prevalent on a paper machine, polymer partitions to inorganic fillers and fiber fines. In the absence of fillers, the polymer adheres to high surface area regions of the fiber, viz., fibrils that result from mechanical fiber processing operations. The roles of surface area, electrostatic interactions, and other papermaking operations are discussed in detail. We believe this study to be the first extension of fluorescence microscopy for visualizing polymer partitioning in complex systems such as papermaking slurries. On the basis of the data provided here, it should be facile to extend this application for studying polymer behavior in other systems such as sludge dewatering and mineral processing.

Analytical staining of cellulosic materials: A review

“…Though the cited article shows that the detailed mechanism is more complicated than previously had been supposed, a correlation between accessible surface area and color depth was confirmed. Whipple and Maltesh (2000) observed a very similar relationship when using fluorescently labeled polymers, the uptake of which on cellulosic materials appeared to be related to surface area; thus the fines and fibrils took up more colorant per unit mass than the larger fibers. Inglesby and Zeronian (2002) found a strong correlation between the specific surface area of cellulose and the uptake of Direct Blue 1.…”

Adsorption of Cationic Flocculants to Paper Slurries

“…1, ex/em 561/583 nm), described previously (24) and summarized in Table 2, were used in these studies (25). For adsorption studies, 1500 mg/L aqueous polymer solutions were prepared from the dry fluorescent polymer.…”

A method for visualising polyelectrolyte distribution after polyelectrolyte conditioning of a biotic sludge

“…This paper discusses the labelling of a commercially available PE (as opposed to polymerisation using fluorescent monomers, e.g. Whipple & Maltesh 2000;Becker et al 2004), the use of different microscopy approaches and points out some caveats encountered in the process. The above mentioned PE distribution was used as a test case for the technique.…”