# thesIt

### (historical effort)

A plot showing surface tension as function of pH showed quite similar relative changes in pH 5-9. Johlin measured using sessile bubble method with different timing (hours) to expect equilibrium.

However, the pattern isn’t the same as Sugden’ result that was imposed over the same plot.

• #### Arif 03:39:24 pm on February 27, 2010 | 0 | # | Tags: abstract, Danielli 1937, interfacial tension, pH, reference

Danielli JF. 1937. The Relations between Surface pH, Ion Concentrations and Interfacial Tension. Proceedings of the Royal Society of London. Series B, Biological Sciences, Vol. 122, No. 827 (Apr. 1, 1937), pp. 155-174

`abstract here`

• #### Arif 03:31:28 pm on February 27, 2010 | 0 | # | Tags: abstract, interfacial tension, Petelska 2002, pH, reference

Petelska AD, Naumowicz M, Figaszewski ZA. 2002. Interfacial tension of the bilayer lipid membrane. Cell Moll Biol Lett 7:212.

A regularity has been found: a larger hydrophilic head gives rise to a lower interfacial tension. A relationship was found between the size of the hydrophilic head of lipid and the isoelectric point pH value. With larger hydrophilic heads, the isoelectric point appears at lower pH.

abstract:
`Vol7_suppl_05_39.pdf`

• #### Arif 03:18:46 pm on February 27, 2010 | 0 | # | Tags: interfacial tension, Johlin 1930, pH, reference

Johlin JM. 1930. The influence of pH and solution concentration on the surface tension of gelatin solutions determined by the sessile bubble method. J Biol Chem 87:319-325.

obtained by the sessile bubble method of measuring surface tensions

`J. Biol. Chem.-1930-Johlin-319-25.pdf`

• #### Arif 01:11:16 pm on February 27, 2010 | 0 | # | Tags: abtract, interfacial tension, Petelska 2000, pH, reference

Effect of pH on the Interfacial Tension of Lipid Bilayer Membrane. Aneta D. Petelska and Zbigniew A. Figaszewski. Biophysical Journal, Volume 78, Issue 2, 812-817, 1 February 2000.

A theoretical equation is derived to describe the dependence of the interfacial tension of a lipid bilayer on the pH of the aqueous solution. Interfacial tension measurements of an egg phosphatidylcholine bilayer were carried out. The experimental results agreed with those derived from the theoretical equation obtained close to the isoelectric point within a range of three pH units. A maximum corresponding to the isoelectric point appears both in the theoretical equation and in the experiment.

`abstract here`

• #### Arif 10:56:17 am on February 27, 2010 | 0 | # | Tags: basic, pH, wikipedia

pH is a measure of the acidity or basicity of a solution, defined as minus the decimal logarithm of the hydrogen ion activity in a solution.

$pH=- log_{10} (a_{H^{+}})$

common pH scale (can't find where water is?)