Non equilibrium reaction http://www.colombospace.com/Youtube/IBa4kgXI4Cg http://commons.wikimedia.org/wiki/File:Bzr_fotos.jpg
I watched the video and it is an interesting chemical effect. If was to guess what is going on, just by looking at the video, what I see is a base chemical reaction, whose reaction rates decay drastically, as the concentration of product increases. As the product diffuse away in a wave, to clean the slate, the reaction rate is once again able to increase. This reaches a peak reaction rate and then quickly drops off again as products build up. These reactions are more than likely exothermic. The energy of reaction goes into entropy instead of reversal, helping to drive the periodic waves of products down the concentration gradient into the solution. Another observation is that the reactions occur at only a finite number of nucleation centers, sort of like the way crystals forms. A crystal would do this if the temperature differential between the crystal melting point and the solution was close. If we have a larger temperature differential you will get more centers. If we quench carbon steel in water, a bunch of tiny crystals form quickly. We get tool steel. If we quench the same iron slowly in boiling oil, we get fewer crystals for flexible steel. In the experiment we have the analogy of a slow quench. The total number of centers reflects the amount of energy transfer needed by the entire solution. With a tight temperature differential, the energy requirement is small so you only need a few centers for the entire solution. In the case of crystals, the molecular entropy lowers into the definitive structures of crystals. The fewest centers means the highest entropy loss, since there is no entropy rebound in the complexity of a zillion centers. In the above case, the entropy rebound results in wave pulses.
Since the container is open for the energy to escape . Once the escapes ,should it not reach the lower condition and the you need add energy to bring it back to the state "0" . then after certain period of time aquering energy from outside geys back to Time 15
from Paul A. LaViolette's book Genesis of the Cosmos . pg , 46 ; " If a beaker full of this solution is kept stirred to ensure homogeneity of the reactants, these color changes will take place simultaneously throughout the entire solution. A complete cycle can take five to ten seconds to complete, depending upon the recipe used to prepare the solution. By sensing the solutions hue with a light meter sensitive to blue light, it is possible to record these oscillations with a chart recorder, as shown in figure 3.5 ( sorry can't show the graph ) . These oscillations are extremely regular , the wave amplitude , period and shape being the same from one wave to the next. Because of the regularity of its oscillations , the B-Z reaction has been termed a " chemical clock "
Interesting what happen if you rise or lover the temperature , will the color be permanent ? Or also if a thermal bead ( very sensitive for temp. measurement ) to see if temp. change as the color change ?
A s heat dissipates it should reach a product , provided the surrounding heat from the environment does not push the reaction back. There are a lot of local reactions and after certain point the summation of the local should expel the total
What precisely are you wanting to know? The Wikipedia page describes the dynamics pretty well. When you compute the concentration equations you end up with something very similar to Lotka-Volterra equations, which can exhibit cyclic behaviour. It's this cyclic behaviour in concentrations which gives the repeated colour change. This behaviour is hypothesised to be the mechanism behind biological internal clocks, ie how we can be asleep and yet wake up very close to the right time. 'm always slightly freaked out when I wake up 30 seconds before my alarm goes off after being asleep for 8 hours.
futher from the book , by Paul A. LaVioletter , PH.D ( Genesis of the Cosmos ) pg.47 " In addition to chemical clock oscillations, B-Z reaction is also able to generate propagating chemical waves, advancing fronts consisting of successive regions of high and low concentrations of certain chemical species (cerous and ceric ion ) . These waves are mostly readily seen when the solution is poured into a laboratory culture dish and forms a shallow layer a few millimeters thick . If it is left unstirred , a tiny blue circular patch eventually nucleates in the initially red-orange solution. This blue color then slowly migrates into the surrounding medium as a blue wave front while the central pacemaker center turns from blue back to red. A complete cycle of color change may take 20 to 60 seconds, depending upon the characteristics of the particular solution. As the pacemaker center continues to oscillate in the regular fashion , it sends out radially expanding rings of red and blue hue, which move forward at the speed of several millimetres per minute. It eventually forms a target pattern consisting of a series of concentric rings similar to the pattern seen in fig.1 ( sorry can't show this fig. wish I could ) . The ceric graph displayed in figure 3.8 presents a cross -sectional-view of one such wave train. Systems scientists term such an energy-dissapating wave pattern a dissipative structure.
futher from Pauls' book pg. 48 , quote " It is also possible to produce several other types of chemical wave behaviour. If the culture dish is briefly tilted to produce a slight mechanical disturbance , ring patterns can sometimes be reshaped into spirals that slowly rotate as the wave fronts propagate outward ( fig. 1, which again I can't show ). Also , by properly adjusting the concentrations of the B-Z reactions ingredients so that the solution remains red thoughout and by momentarily touching one spot with a heated needle , it is possible to induce a solitary blue wave to form and propagate outward through the surrounding red solution . In some ways this expanding ring resembles the kind of wave produced when a stone is dropped into a still pond. In this case , however , the disturbance is chemical in nature rather than mechanical. In fact , mechanical agitation of the solution destroys the delicate chemical wave "
I'm still not clear on what you're wanting to know. You've obviously read something on the subject. Are you looking for the mathematical description behind those things? Chemical networks are where you want to look. You can model a population of different chemicals via chemical reactions and the effects this has on the totals/concentrations. That's how you get the LV equations for the systems you describe. To then get the spatial structure you describe in the above post you construct such chemical networks on a lattice, each site has a separate network and dynamics. You then couple them together by including diffusion processes. To really dial it up a knotch you can constructv a Fock space representation, take the continuum limit and then use a form of quantum field theory to describe the system! I can give you author names and paper links if you're after such things or is that too detailed?
Why did you ask if anyone know about B-Z reactions if all you want to do it spit out factoids about them? Your openning post gave the impression you were after information yet when I've asked you what information you want to know you just spit out another fact.
yes the point is , is to flex the imagination to go round and round with what is known , leads to nothing new
