Atomic Force Microscopy of Humic Substances:  Effects of pH and Ionic Strength

1999 ◽  
Vol 33 (21) ◽  
pp. 3911-3917 ◽  
Author(s):  
Eric Balnois ◽  
Kevin J. Wilkinson ◽  
Jamie R. Lead ◽  
Jacques Buffle
Keyword(s):  
Atomic Force Microscopy ◽  
Ionic Strength ◽  
Humic Substances ◽  
Force Microscopy ◽  
Atomic Force ◽  
Effects Of Ph

scholarly journals Atomic force microscopy of gastric mucin and chitosan mucoadhesive systems

2000 ◽  
Vol 348 (3) ◽  
pp. 557-563 ◽  
Author(s):  
Matthew P. DEACON ◽  
Simon McGURK ◽  
Clive J. ROBERTS ◽  
Phillip M. WILLIAMS ◽  
Saul J. B. TENDLER ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Atomic Force Microscopy ◽  
Ionic Strength ◽  
Average Length ◽  
Gastric Mucin ◽  
Acetate Buffer ◽  
Force Microscopy ◽  
Atomic Force ◽  
Molecular Hydrodynamic ◽  
Hydrodynamic Data

Atomic force microscopy has been utilized to probe, at a molecular level, the interaction between purified pig gastric mucin (PGM) and a mucoadhesive cationic polymer, chitosan (sea cure 210+), with a low degree (approx. 11%) of acetylation. Images were produced detailing the structures of both PGM and chitosan in 0.1 M acetate buffer (pH 4.5), followed by the complex of the two structures in the same buffer. PGM in 0.1 M acetate buffer revealed long linear filamentous structures, consistent with earlier electron microscopy and scanning tunnelling micoscopy studies. The chitosan molecules also adopted a linear conformation in the same buffer, although with a smaller average length and diameter. They appeared to adopt a stiff-coil conformation consistent with earlier hydrodynamic measurements. The complexes formed after mixing PGM and chitosan together revealed large aggregates. In 0.1 M ionic strength buffer they were of the order of 0.7 μm in diameter, consistent with previous electron microscopy studies. The effect of ionic strength of the buffer on the structure of the complex was also studied and, together with molecular hydrodynamic data, demonstrates that the interaction is principally electrostatic in nature.

Investigation of adsorbed humic substances using atomic force microscopy

2004 ◽  
Vol 248 (1-3) ◽  
pp. 17-23 ◽  
Author(s):  
Shoeleh Assemi ◽  
Patrick G. Hartley ◽  
Peter J. Scales ◽  
Ronald Beckett
Keyword(s):  
Atomic Force Microscopy ◽  
Humic Substances ◽  
Force Microscopy ◽  
Atomic Force

Dependence of Purple Membrane Bump Curvature on pH and Ionic Strength Analyzed Using Atomic Force Microscopy Combined with Solvent Exchange

2014 ◽  
Vol 118 (31) ◽  
pp. 9322-9328 ◽  
Author(s):  
Yasunori Yokoyama ◽  
Kosuke Yamada ◽  
Yosuke Higashi ◽  
Satoshi Ozaki ◽  
Haorang Wang ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Ionic Strength ◽  
Purple Membrane ◽  
Solvent Exchange ◽  
Force Microscopy ◽  
Atomic Force
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