The bubbles are observed by mixing of fine powder of iron into carbonated water. Large bubble formed from the small bubbles by unification. It carries the fine powder of iron to the surface of water. The bubble at surface of water will burst, and the debris will sink to bottom. Robustness of the bubble increases after repetition of creation and destruction. These bubbles are generated after a few hours from the mixing, but those are not generated after a week. The measured value of pH (acidity) indicates that the bubbles are suitable for the existence of hydrogen-carbonate (HCO3-). It is considered that the membrane of the bubble is formed by intermolecular binding force between HCO3- and Fe2+. The membrane is able to accumulate molecules selectively in order to form an organization of molecules. It might have been functioned as a platform of chemical evolution, because the ultraviolet light in the early earth is able to provide the energy to cause chemical reactions.
Adsorption of 20 bio-amino acids at pH 4, 6, and 8 was carried out using short-range order soil minerals, viz. allophane and imogolite. The initial concentration of the amino acid solution was fixed at 2.5 mmol⋅dm-3. We compared the extent of adsorption of the 20 amino acids by allophane and imogolite. Both allophane and imogolite adsorbed cysteine, aspartic acid, glutamic acid, lysine, arginine, and histidine considerably well at all three pH values, while they poorly adsorbed glycine, alanine, valine, leucine, isoleucine, methionine, threonine, tryptophan, and proline. The dissociation of each amino acid affects the adsorption behavior as well as the surface charges of allophane and imogolite. The amino acids that were easily adsorbed by allophone and imogolite harbored a carboxyl or amino group on their side chain. The extent of adsorption of allophane was quite similar to that of imogolite, because the surface charge of allophane is almost the same as that of imogolite at pH 4, 6, and 8. In addition, we investigated whether allophane and imogolite were able to differentiate between D- and L-amino acids. Our results suggest that such discrimination is not feasible.