Laser light-scattering study of polyacrylamides with and without hydrolyzation in 0.35M KH2PO4 aqueous solution
✍ Scribed by Mohammad Siddiq; Chi Wu
- Publisher
- John Wiley and Sons
- Year
- 1997
- Tongue
- English
- Weight
- 171 KB
- Volume
- 63
- Category
- Article
- ISSN
- 0021-8995
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✦ Synopsis
Both the hydrolyzed and unhydrolyzed polyacrylamides with different molar masses were characterized in 0.35 M KH 2 PO 4 aqueous solution at 25ЊC by laser light scattering (LLS). The Laplace inversion of precisely measured intensity-intensity time correlation function leads to an estimate of the characteristic line-width distribution G(G) which can be further reduced to a translational diffusion coefficient distribution G(D). A combination of the measured weight-average molar mass M w and G(D) enables us to establish a calibration of D (cm 2 /s) Å (4.46 { 0.02) 1 10 05 M 00.50{0.003 . Using this calibration, we convert each G(D) into a corresponding molar mass distribution. The calculated M w from such a molar mass distribution is reasonably close to the measured M w from static LLS. Most important is that when 0.35M KH 2 PO 4 aqueous solution is used as solvent, both the hydrolysed and unhydrolysed polyacrylamides can be represented by an identical calibration; namely, in 0.35 M KH 2 PO 4 aqueous solution, the polyelectrolytes effect in the hydrolysed polyacrylamides has been suppressed. Therefore, the hydrolysed polyacrylamides can be characterized as a normal neutral polymer in 0.35M KH 2 PO 4 aqueous solution, which makes a routine characterization of the hydrolysed polyacrylamides much easier.