TY - JOUR
T1 - Spatial structures generated by chemical reactions at interfaces
AU - Avnir, David
AU - Kagan, Michael
PY - 1984
Y1 - 1984
N2 - Far-from-equilibrium networks of physicochemical processes may exhibit structuring1, in time (for example, chemical oscillations 2), in space (stationary patterns3) or as a combination of both (chemical waves4). Much experimental effort has been invested during the past two decades in temporal and spatio-temporal phenomena 2,4; and except for periodic precipitation processes5 no general chemical system was available for a wide experimental study of the evolution of spatial structures. Recently, however, we have revealed a remarkably wide family of processes which produce spatial structures: chemical reactions at liquid interfaces. These include reactions at gas/liquid interfaces6, and photochemical reactions at liquid/air7,8 and liquid/liquid8 interfaces. We now report yet another important class: reactions at membrane surfaces, as shown in Fig. 1. Although hydrodynamic slow currents are apparent at a mature stage of the structure development, the actual mechanism leading to the initial structuring is as yet not clear. We show, however, that these structures are not a visualizing method of patterns caused by evaporative cooling9,10: structures are formed also in the absence of such patterning and hydrodynamic currents start only after chemical structures are formed. Some of our observations suggest that chemical reaction is necessary for structure evolution, and that gravity apparently plays no role in this phenomenon.
AB - Far-from-equilibrium networks of physicochemical processes may exhibit structuring1, in time (for example, chemical oscillations 2), in space (stationary patterns3) or as a combination of both (chemical waves4). Much experimental effort has been invested during the past two decades in temporal and spatio-temporal phenomena 2,4; and except for periodic precipitation processes5 no general chemical system was available for a wide experimental study of the evolution of spatial structures. Recently, however, we have revealed a remarkably wide family of processes which produce spatial structures: chemical reactions at liquid interfaces. These include reactions at gas/liquid interfaces6, and photochemical reactions at liquid/air7,8 and liquid/liquid8 interfaces. We now report yet another important class: reactions at membrane surfaces, as shown in Fig. 1. Although hydrodynamic slow currents are apparent at a mature stage of the structure development, the actual mechanism leading to the initial structuring is as yet not clear. We show, however, that these structures are not a visualizing method of patterns caused by evaporative cooling9,10: structures are formed also in the absence of such patterning and hydrodynamic currents start only after chemical structures are formed. Some of our observations suggest that chemical reaction is necessary for structure evolution, and that gravity apparently plays no role in this phenomenon.
UR - http://www.scopus.com/inward/record.url?scp=0000183247&partnerID=8YFLogxK
U2 - 10.1038/307717a0
DO - 10.1038/307717a0
M3 - ???researchoutput.researchoutputtypes.contributiontojournal.article???
AN - SCOPUS:0000183247
SN - 0028-0836
VL - 307
SP - 717
EP - 720
JO - Nature
JF - Nature
IS - 5953
ER -