Polymer latex particle size measurement through high speed dielectric spectroscopy

Wiley - Tập 39 Số 11-12 - Trang 2419-2441 - 1990
Bryan B. Sauer1, Ruth S. Stock1, Kyung‐Hee Lim1, W. Harmon Ray1
1Department of Chemical Engineering, University of Wisconsin, Madison, Wisconsin 53706

Tóm tắt

AbstractDielectric techniques have been implemented to study aqueous colloidal suspensions. A four electrode cell was used in two configurations; the first, a sweep of frequencies using a sequence of standard single frequency null‐balance measurements, and the second relying on the dielectric response to a Fourier synthesized pseudo random white noise (FSPN) with measurements performed using correlation techniques in the time domain. Single frequency measurements, which take on the order of 5–10 min per spectrum, were performed on polymer latex standards of varying size, latex concentration, and electrolyte concentration and were extended from 0.02 to over 500 kHz. It was found that the central relaxation frequency fc was inversely propotional to the square of the particle size, consistent with previous experimental results. Experiments were performed at different particle concentration and ionic strengths, and the magnitude and breadth of the dielectric dispersion was analyzed in terms of current theories. The distribution of relaxation times was found to be in general qualitative agreement with those predicted by some existing theories. The results indicate that a wide range of conditions exist in terms of latex concentration and ionic environment where the rapid and accurate measurement of polymer latex particle size and size distribution is feasible. FSPN measurements, which take on the order of seconds, were shown to be accurate over a moderate frequency range for model electrical network studies but were only partially successful for aqueous suspensions of latex because of high frequency limitations in the electronics. Experimental details and difficulties concerning the application of this technique are discussed.

Từ khóa


Tài liệu tham khảo

10.1021/j100818a066

10.1016/0021-9797(76)90321-0

10.1016/0021-9797(79)90112-7

M. M.Springer Ph.D. thesis University of Wageningen Denmark 1979.

10.1016/0301-4622(81)87005-6

10.1016/S0022-0728(83)80005-9

10.1016/0021-9797(86)90369-3

10.1143/JJAP.14.2039

10.1016/0301-4622(80)87003-7

D. F.Myers Ph.D. thesis Princeton University 1988.

10.1016/0021-9797(89)90187-2

10.1016/0021-9797(89)90188-4

10.1063/1.1134583

10.1111/j.1749-6632.1977.tb55923.x

10.1063/1.329051

10.1063/1.1750906

deLacey E. H. B., 1981, Chem. Soc., Faraday Trans., 2, 77

10.1063/1.444369

10.1021/j100295a086

10.1063/1.454857

10.1063/1.1683413

Schwan H. P., 1963, Physical Techniques in Biological Research

R. S.Stock Ph.D. thesis University of Wisconsin‐Madison 1986.

10.1063/1.1680844

10.1021/j100581a022

10.1039/df9664200154

10.1016/S0022-0728(72)80221-3

Thông tin
Thông tin xuất bản

Wiley

Tập 39 Số 11-12

2419-2441

Thông tin tác giả