{{Short description|Color-changing redox chemical reaction}} thumb|right|Blue bottle reaction video|244x244px
The '''blue bottle experiment''' is a color-changing redox chemical reaction. An aqueous solution containing glucose, sodium hydroxide, methylene blue is prepared in a closed bottle containing some air. Upon standing, it spontaneously turns from blue to colorless due to reduction of methylene blue by the alkaline glucose solution. However, shaking the bottle oxidizes methylene blue back into its blue form. With further shaking, this color-change cycle can be repeated many times.<ref name="The 'blue bottle' reaction">{{cite magazine|last=Baker|first=Colin|title=The 'blue bottle' reaction|url=https://eic.rsc.org/exhibition-chemistry/the-blue-bottle-reaction/2020070.article|magazine=Education in Chemistry|date=1 November 2006|volume=43|issue=6|page=155|publisher=Royal Society of Chemistry}}</ref> This experiment is a classic chemistry demonstration that can be used in laboratory courses as a general chemistry experiment to study chemical kinetics and reaction mechanism.<ref>{{cite journal |last1=Engerer |first1=Steven C. |last2=Cook |first2=A. Gilbert |title=The Blue Bottle Reaction as a General Chemistry Experiment on Reaction Mechanisms |journal=Journal of Chemical Education |date=1999 |volume=76 |issue=11 |pages=1519–1520 |doi=10.1021/ed076p1519|bibcode=1999JChEd..76.1519E }}</ref> The reaction also works with other reducing agents besides glucose<ref>{{cite journal|last1=Cook|first1=A. Gilbert|last2=Tolliver|first2=Randi M.|last3=Williams|first3=Janelle E.|title=The Blue Bottle Experiment Revisited: How Blue? How Sweet?|journal=Journal of Chemical Education|date=1994|volume=71|issue=2|page=160|doi=10.1021/ed071p160|bibcode=1994JChEd..71..160C}}</ref> and other redox indicator dyes besides methylene blue.<ref name=Lim2017>{{cite journal|last1=Limpanuparb|first1=Taweetham|last2=Areekul|first2=Cherprang|last3=Montriwat|first3=Punchalee|last4=Rajchakit|first4=Urawadee|title=Blue Bottle Experiment: Learning Chemistry without Knowing the Chemicals|journal=Journal of Chemical Education|volume=94|issue=6|page=730|date=2017|doi=10.1021/acs.jchemed.6b00844|bibcode=2017JChEd..94..730L}}</ref>
== Reactions == === History and general concept === [[File:Blue Bottle Reaction.png|alt=|right|thumb|310x310px|Blue Bottle Reaction Scheme<ref>{{Cite journal|last1=Limpanuparb|first1=Taweetham|last2=Roongruangsree|first2=Pakpong|last3=Areekul|first3=Cherprang|date=2017|title=A DFT investigation of the blue bottle experiment: E<sup>∘</sup> half-cell analysis of autoxidation catalysed by redox indicators|journal=Royal Society Open Science|language=en|volume=4|issue=11|article-number=170708|doi=10.1098/rsos.170708|doi-access=free|pmid=29291061|pmc=5717635}}</ref><ref name=":0">{{Cite journal|last1=Limpanuparb|first1=Taweetham|last2=Ruchawapol|first2=Chattarin|last3=Pakwilaikiat|first3=Pooh|last4=Kaewpichit|first4=Chatchapong|date=2019|title=Chemical Patterns in Autoxidations Catalyzed by Redox Dyes|journal=ACS Omega|volume=4|issue=4|pages=7891–7894|doi=10.1021/acsomega.9b00802 |pmid=31459876 |pmc=6648442|url=https://figshare.com/articles/Chemical_Patterns_in_Autoxidations_Catalyzed_by_Redox_Dyes/8059952/files/15019703.pdf|doi-access=free}}</ref>]]
The mechanism of the blue bottle experiment requires an understanding of rates and mechanisms of complex interacting chemical reactions. In complex chemical reactions, individual sub-reactions can occur simultaneously but at significantly different rates. These, in turn, can be affected by reagent concentration and temperature. In most cases, the overall reaction rate is determined by the fastest single component reaction. However, when some processes form intermediate molecules which then react in other processes to form the end product, the rate of the overall reaction is determined by the rate of the slowest reaction. In such circumstances the intermediate products are usually in a steady state at low concentrations because they are highly reactive.<ref>{{cite journal |last1=Campbell |first1=J. A. |title=Kinetics Early and Often |journal=Journal of Chemical Education |date=1963 |volume=40 |issue=11 |pages=578–583 |doi=10.1021/ed040p578|bibcode=1963JChEd..40..578C }}</ref> Equilibrium state requires that all reaction forward and backward mechanism happens at the same rate.<ref>{{cite journal |last1=Mickey |first1=Charles D. |title=Chemical Kinetics: Reaction Rates |journal=Journal of Chemical Education |date=1980 |volume=57 |issue=9 |page=659 |doi=10.1021/ed057p659|bibcode=1980JChEd..57..659M }}</ref> Thus, the overall net reaction is determined by the sum of all the mechanism steps where the rate depends on the concentration and temperature. The blue bottle experiment illustrates this principle of interacting reactions with different rates.<ref name="Lim2017" />
The blue bottle experiment requires only three reagents: potassium hydroxide solution, dextrose solution, and dilute methylene blue solution. These reagents are added to a flask, mixed, and the flask is stoppered. The initial color of the solution is blue, but upon standing for a short interval it spontaneously fades to colorless, as the alkaline dextrose solution reduces the methylene blue to colorless leuco-methylene blue. Shaking the flask causes oxygen present in the head space air to dissolve in the solution and oxidize the leuco-methylene blue back to its colored form again.<ref>{{cite journal |last1=Dutton |first1=F. B. |title=Methylene Blue - Reduction and Oxidation |journal=Journal of Chemical Education |date=1960 |volume=37 |issue=12 |page=A799 |doi=10.1021/ed037pA799.1|bibcode=1960JChEd..37A.799D }}</ref> Another variation uses methylene blue in water, glucose, and caustic soda (NaOH).<ref name=Clockreaction>{{cite journal |last1=Limpanuparb |first1=Taweetham |last2=Ruchawapol |first2=Chattarin |last3=Sathainthammanee |first3=Dulyarat |title=Clock Reaction Revisited: Catalyzed Redox Substrate-Depletive Reactions |journal= Journal of Chemical Education|date=2019 |volume=96 |issue=4 |page=812−818 |doi=10.1021/acs.jchemed.8b00547|bibcode=2019JChEd..96..812L |s2cid=104370691 }}</ref> There are many versions of the experiment, however, unlike the classical version where dye is necessary to use as a catalyst for the reaction, the green and rapid versions undergo autoxidation even in the absence of the dye.<ref name=":1">{{Cite journal|last=Kerdkaew, Thitipong; Limpanuparb, Taweetham|title=The Blue Bottle Experiment Revisited: How Much Oxygen?|url=https://pubs.acs.org/doi/10.1021/acs.jchemed.9b01103|journal=Journal of Chemical Education|year=2020|volume=97|issue=4|pages=1198–1202|doi=10.1021/acs.jchemed.9b01103|bibcode=2020JChEd..97.1198K |s2cid=216217791|url-access=subscription}}</ref>
In the past, it was thought that the reaction occurred by the oxidation of an aldehyde group to a carboxylic acid under alkaline conditions. For instance, glucose would be oxidized to gluconate by oxygen.<ref>{{cite book|last1=Olah|first1=Herbert W. Roesky|title=Spectacular chemical experiments|date=2007|publisher=Wiley-VCH|location=Weinheim|isbn=978-3-527-31865-0|edition= 1st Aufl.}}</ref> However, the experiment also works with compounds such as vitamin C and benzoin, which do not contain an aldehyde group.<ref name="Lim2017" /> Thus, the reaction is actually the oxidation of an acyloin or related α-hydroxycarbonyl group, which is a structural feature of glucose, to a 1,2-diketone.<ref name="Anderson" /> The reduced redox dye (colorless state) is formed from oxidized redox dye (blue). The color-change that occurs in the blue bottle experiment has features of a clock reaction, in which a visible change in the concentration of one or more reagents suddenly occurs upon the exhaustion of a limiting reagent. For example, the limiting reactant, oxygen, is consumed by another reactant, benzoin, with the help of safranin as a catalyst. Once the limited amount of oxygen has been used up, the catalyst is unable to change forms, and as a result, the solution changes color.
right|thumb|Blue Bottle in Different Temperature Time-lapse Coldest (left) to Warmest (right)|246x246px thumb|Blue Bottle with Manometer Video|327x327px thumb|Blue Bottle with Manometer|245x245px
=== Classical version ===
The aqueous solution in the classical reaction contains glucose, sodium hydroxide and methylene blue.<ref>{{cite book|last1=Shakhashiri|first1=Bassam Z.|title=Chemical demonstrations|date=1985|publisher=Univ. of Wisconsin Press|location=Madison, Wis.|isbn=978-0-299-10130-5|pages=142–143|edition= [Nachdr.]}}</ref> In the first step an acyloin of glucose is formed. The next step is a redox reaction of the acyloin with methylene blue in which the glucose is oxidized to diketone in alkaline solution<ref name=":0"/> and methylene blue is reduced to colorless leucomethylene blue. If there is enough oxygen available (i.e., after shaking the bottle), leucomethylene blue is immediately re-oxidized to methylene blue and the blue color of the solution persists. However, when the solution is left to rest, the dissolved oxygen is gradually irreversibly<ref name=":1" /> consumed, and at the point where it has been completely exhausted, the glucose reduction of methylene blue proceeds unopposed and the color of the solution rapidly disappears.<ref>{{cite book|last1=Summerlin|first1=Lee R.|title=Chemical demonstrations|date=1988|publisher=American Chem. Society|location=Washington, DC|isbn=978-0-8412-1481-1|page=127|edition= 2nd}}</ref> The reaction is first order in glucose, methylene blue and hydroxide ion and zero-order in oxygen. The process can be described as a pseudo first order reaction, and can be used to illustrate the changing concentrations of the reagents over the course of the reaction as the solution changes from blue back to colorless.<ref name="The 'blue bottle' reaction"/>
The final glucose oxidation products besides sodium gluconate have been identified as {{small|D}}-arabino-hexos-2-ulose (glucosone), the anion of {{small|D}}-arabinonate after splitting off of a formate anion and arabinonic acid.<ref name=Anderson>{{cite journal |last1=Anderson |first1=Laurens |author-link1=Laurens Anderson|last2=Wittkopp |first2=Stacy M. |last3=Painter |first3=Christopher J. |last4=Liegel |first4=Jessica J. |last5=Schreiner |first5=Rodney |last6=Bell |first6=Jerry A. |last7=Shakhashiri |first7=Bassam Z. |author-link7=Bassam Shakhashiri|title=What Is Happening When the Blue Bottle Bleaches: An Investigation of the Methylene Blue-Catalyzed Air Oxidation of Glucose |journal=Journal of Chemical Education |date=2012 |volume=89 |issue=11 |pages=1425–1431 |doi=10.1021/ed200511d|bibcode=2012JChEd..89.1425A }}</ref>
=== Sustainable version === Wellman and Noble proposed a new formulation for the Blue Bottle experiment in which vitamin C serves as a reducing agent instead of glucose; the methylene blue and oxygen are still used. Copper is added as a catalyst for the reoxidation of leucomethylene blue to methylene blue. These modifications give an experiment that generates a smaller amount of waste that is less corrosive and easier to neutralize, along with changing the mixture color to a green-blue color, and therefore is an example of green chemistry modification.<ref name="green">{{Cite journal|last1=Wellman|first1=Whitney E.|last2=Noble|first2=Mark E.|last3=Healy|first3=Tom|date=2003|title=Greening the Blue Bottle|journal=Journal of Chemical Education|language=EN|volume=80|issue=5|page=537|doi=10.1021/ed080p537|bibcode=2003JChEd..80..537W}}</ref><ref name=Rajchakit2016>{{cite journal|last1=Rajchakit|first1=Urawadee|last2=Limpanuparb|first2=Taweetham|date=2016|title=Greening the Traffic Light: Air Oxidation of Vitamin C Catalyzed by Indicators|journal=Journal of Chemical Education|volume=93|issue=8|pages=1486–1489|bibcode=2016JChEd..93.1486R|doi=10.1021/acs.jchemed.5b00630}}</ref>
=== Rapid version ===
The Chen<ref>{{cite journal|last1=Chen|first1=Philip S.|title=Autoxidation of benzoin|journal=Journal of Chemical Education|date=1970|volume=47|issue=1|pages=A67|doi=10.1021/ed047pA67.1|bibcode=1970JChEd..47...67C}}</ref> autoxidation of benzoin had performed a similar experiment with respect to the classical and green versions. It was found that the traffic light and vanishing valentine experiments can become successful regardless of whether a sugar is added. One variation is more rapid, with the number of color change cycles do not last as long as the classical and green versions because the reactants are present in smaller amounts; also, the reducing agent for this experiment is benzoin, which is added to help increase the number of cycles in the solution. Moreover, the usable period in this experiment is quite short. Although the experiment is prepared overnight, the reducing agent can be added at any time to be able to observe the solution more.<ref name=rapid>{{cite journal|last1=Rajchakit|first1=Urawadee|last2=Limpanuparb|first2=Taweetham|title=Rapid Blue Bottle Experiment: Autoxidation of Benzoin Catalyzed by Redox Indicators|journal=Journal of Chemical Education|date=2016|volume=93|issue=8|pages=1490–1494|doi=10.1021/acs.jchemed.6b00018|bibcode=2016JChEd..93.1490R}}</ref>
=== Enzymatic version ===
Zhang, Tsitkov, and Hess from Columbia University<ref>{{cite journal |last1=Zhang |first1=Yifei |last2=Tsitkov |first2=Stanislav |last3=Hess |first3=Henry |title=Complex dynamics in a two-enzyme reaction network with substrate competition |journal=Nature Catalysis |date=2018 |volume=1 |issue=4 |pages=276–281 |doi=10.1038/s41929-018-0053-1|s2cid=104228290 }}</ref> proposed an enzymatic version of the "blue bottle experiment". They named it the "green bottle experiment", since the system is colored green and the reagents are safer than classical approaches. The experiment is performed in a clear glass vial containing two common enzymes (glucose oxidase and horseradish peroxidase), glucose, and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (abbreviated as ABTS) in PBS buffer. A thin layer of oil is used to block the solution from the air. The solution initially turns green and then turns colorless with the depletion of dissolved oxygen. Shaking the solution introduces fresh oxygen and colors the solution green again until the oxygen is consumed.
This version relies on three enzymatic reactions. First, the glucose oxidase catalyzes the oxidation of glucose in the presence of oxygen and produces hydrogen peroxide. Second, the horseradish peroxidase utilizes the hydrogen peroxide to oxidize ABTS to its radical cationic form, ABTS<sup>+•</sup>. As the dissolved oxygen is consumed in the solution, the third reaction occurs: glucose oxidase catalyzes the reduction of ABTS<sup>+•</sup> back to ABTS in the presence of glucose. This system can also form beautiful patterns arising from reaction-driven Rayleigh–Bénard convection.<ref>A movie can be found here: [https://www.youtube.com/watch?v=Mw-sGcuP5B0 Green bottle experiment]</ref>
== Variation of dyes ==
The chemical reactions and mechanism in the blue bottle experiment rely on the oxidation of a sugar with the aid of air and a redox dye in a basic solution. Other variations of this reaction have been reported that use four families of redox dyes: thiazines, oxazines, azines, and indigo carmine have all been reported to work with glucose and caustic soda.<ref name=rapid/>
=== Chemical traffic light experiment ===
The chemical traffic light is a color-changing redox reaction that is related to the blue bottle experiment. One of the early formulas consists of glucose, sodium hydroxide, indigo carmine (dye), and water. Another formula consists of indigo carmine, ascorbic acid (Vitamin C), sodium bicarbonate, sodium chloride, copper(II) sulfate, sodium hydroxide and water.<ref name=Rajchakit2016/> By doing so, chemical waste and the level of corrosive chemicals is reduced. The amount of solid chemicals dissolved in the experiment could be reduced from 60 grams to 6 grams. And the pH could be lowered from 13 to 3 which is easier to neutralize the pH to 7 by adding baking soda before disposal.<ref name=green/> Also, it is safer and the reactions also occur faster and are easier to perform.
At first, all chemicals are added together and the color appears yellow. After shaking, the color turns green and then changes to red after it is left untouched. When further observed, the color turns back to yellow, which is why the solution is called the chemical traffic light. This reaction can be repeated many times, but it needs additional oxygen or indigo carmine.
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This reaction occurs by oxidation and reduction of the solution where alkaline glucose solution is acting as a reducing agent. The glucose solution is added to the solution containing indicator (dye indigo carmine) the color changes occur. This reaction is also known as chemical clock experiment because concentrations of the products and reactants changed over the specific period.<ref>{{cite web |last1=Mann |first1=Georgia |title=Chemistry Week: Chemical traffic light |url=https://blog.frontiersin.org/2015/10/22/chemistry-week-chemical-traffic-light/ |access-date=17 July 2019}}</ref> When the solution is shaken, oxygen dissolves in the solution and oxidizes indigo carmine. Solution becomes red if a small amount of oxygen is dissolved, and green if all of indigo carmine is oxidized.<ref>{{cite web|title=Chemical Traffic Light|url=http://practicum.melscience.com/experiments/chemical-traffic-light.html|website=MEL Science|access-date=17 July 2019|archive-date=1 October 2020|archive-url=https://web.archive.org/web/20201001013307/https://practicum.melscience.com/experiments/chemical-traffic-light.html}}</ref> The solution will turn back to original yellow color when the concentration of oxygen level drops.<ref>{{cite web |last1=Altott |first1=April |title=Traffic Light |url=http://chemistry.elmhurst.edu/demos/trafficlight2.htm |access-date=17 July 2019 |archive-date=8 September 2019 |archive-url=https://web.archive.org/web/20190908084908/http://chemistry.elmhurst.edu/demos/trafficlight2.htm }}</ref>
<gallery> File:Chemical traffic light reaction time-lapse.webm|Chemical traffic light reaction time-lapse File:Chemical traffic light reaction (yellow).jpg|Chemical traffic light reaction (yellow) File:Chemical traffic light reaction (red).jpg|Chemical traffic light reaction (red) File:Chemical traffic light reaction (green).jpg|Chemical traffic light reaction (green) </gallery>
=== Vanishing valentine experiment ===
The vanishing valentine experiment is another chemical reaction related to the blue bottle experiment. This reaction occurs when water, glucose, sodium hydroxide, and resazurin is mixed in a flask. When the solution is shaken, it turns from light blue to a reddish color. The solution turns back to a light blue after being left to stand for a while. This reaction can be repeated several times.<ref>{{cite web|title=Vanishing Valentine Chemistry Demonstration|url=http://chemistry.about.com/od/valentinesdaychemistry/a/Vanishing-Valentine-Chemistry-Demonstration.html|access-date=13 November 2015}}{{Dead link|date=July 2020 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>
After mixing all the components, shake the bottle and the color will turn to red or pink depend on the amount of resazurin in the solution. More resazurin will result in more time needed for the solution to turn back the color and the intensity of the red color.
frameless|548x548px|Vanishing Valentine Equation
The chemical reaction stimulates glucose to reduce resazurin to resorufin. It would then be reduced again into a colorless compound called dihydroresorufin. When dihydroresorufin is shaken, it is oxidized back to resorufin. This is due to the fact that shaking it results oxygen in the bottle to oxidized dihydroresorufin back into resorufin.<ref>{{cite web|title=The Vanishing Valentine|url=http://www.flinnsci.com/documents/demopdfs/chemistry/cf0667.00.pdf|access-date=13 November 2015|archive-url=https://web.archive.org/web/20160216035424/http://www.flinnsci.com/documents/demopdfs/chemistry/cf0667.00.pdf|archive-date=16 February 2016}}</ref>
<gallery> File:Vanishing Valentine.webm|solution turn from colorless to red File:Vanishing valentine before shook.JPG|reduced color of the experiment File:Vanishing valentine after shook.JPG|oxidized color of the experiment </gallery>
=== Others ===
;Gatorade Erioglaucine, a food colorant and a redox dye, was found to be an effective substitute for methylene blue in the blue bottle experiment. Since some candies and drinks such as Gatorade contain the dye and a reducing sugar, only sodium hydroxide need be added to turn these food products into a blue bottle solution.<ref>{{cite journal |last1=Campbell |first1=Dean J. |last2=Staiger |first2=Felicia A. |last3=Peterson |first3=Joshua P. |title=Variations on the "Blue-Bottle" Demonstration Using Food Items That Contain FD&C Blue #1 |journal=Journal of Chemical Education |date=2015 |volume=92 |issue=10 |pages=1684–1686 |doi=10.1021/acs.jchemed.5b00190|bibcode=2015JChEd..92.1684S }}</ref>
;Purple flask Thionine can be used in the green version of the experiment in combination with copper/iron catalyst to create the purple flask.<ref>{{cite journal |last1=Weinberg |first1=Richard B. |title=The Purple Flask: A Novel Reformulation of the Blue Bottle Reaction |journal=Journal of Chemical Education |date=2019 |volume=97 |pages=159–161 |doi=10.1021/acs.jchemed.9b00627|s2cid=209704047 }}</ref>
==Pattern formation==
Pattern formation is when a solution containing NaOH, glucose, and dye is poured into a Petri dish that is open to the atmosphere.<ref>{{Cite journal|last1=Adamcíková|first1=L'ubica|last2=Sevcík|first2=Peter|date=1998-12-01|title=The Blue Bottle Experiment - Simple Demonstration of Self-Organization|journal=Journal of Chemical Education|volume=75|issue=12|page=1580|doi=10.1021/ed075p1580|bibcode=1998JChEd..75.1580A |issn=0021-9584}}</ref> This will result in solution changing its structure over a period of time. Structures arise from molecular transport through diffusion and chemical kinetics. Patterns formed in the Petri dish can be described as a mosaic pattern; web-like, dynamic spiral, branching, and lines connecting to each others.<ref>{{cite journal |last1=Pons |first1=A. J. |last2=Sague´s |first2=F. |last3=Bees |first3=M. A. |last4=Sørensen |first4=P. Graae |title=Pattern Formation in the Methylene-Blue-Glucose System |journal=The Journal of Physical Chemistry B |date=2000 |volume=104 |issue=10 |pages=2251–2259 |doi=10.1021/jp9935788}}</ref>
Changes in pattern formation are not homogeneous and can be affected by several factors. Different types of dye in solution will give the same pattern because of the bond's formation and the dynamics remain the same, this is because the solution has the same colour as the dye. Different amounts of dye can result in density change in the solution and this results in changing of convective motion. Different amounts of dye can bring in different amounts of convention cells which are also formed by different amounts of glucose and oxidized product. This can result in an interesting spatial phenomena. Time can also affect pattern formation. As the time passed, one pattern gradually faded away. Spirals and branches started to disappear and eventually disappeared fully. These facts indicate that oxygen affects the chemical reaction and this plays a fundamental role in the pattern formation. Pattern formation may also form from a chemically driven convective instability. This means that matter is exchanged across the air-reaction mixture interface, due to the fluctuations in the molecular nature of chemical systems.<ref>{{cite journal |last1=Adamčíková |first1=L` |last2=Ševčík |first2=P. |title=The Blue Bottle Experiment and Pattern Formation in this System |journal=Z. Naturforsch. |date=1997 |volume=52 |issue=8–9| pages=650–654 |doi=10.1515/zna-1997-8-918|doi-access=free |bibcode=1997ZNatA..52..650A }}</ref> The temperature can affect the formation of pattern.<ref name=":0" /> Colder temperature formed a clearer pattern than hot temperature. The shape of the Petri dish also contributed to the pattern formation.<ref name=":0" />
<gallery> File:Pattern Formation from Blue Bottle Experiment in Ice Water Bath.webm|Pattern Formation from Blue Bottle Experiment in Ice Water Bath Time-lapse File:Pattern Formation from Blue Bottle Experiment in Ice Water Bath.jpg|Pattern Formation from Blue Bottle Experiment in Ice Water Bath File:Pattern Formation from Blue Bottle Experiment in Cold Water Bath.webm|Pattern Formation from Blue Bottle Experiment in Cold Water Bath Time-lapse File:Pattern Formation from Blue Bottle Experiment in Cold Water Bath.jpg|Pattern Formation from Blue Bottle Experiment in Cold Water File:Pattern Formation from Blue Bottle Experiment in Room Temperature.webm|Pattern Formation from Blue Bottle Experiment in Room Temperature Time-lapse File:Pattern Formation from Blue Bottle Experiment in Room Temperature.jpg|Pattern Formation from Blue Bottle Experiment in Room Temperature File:Pattern Formation from Blue Bottle Experiment in Warm Water Bath.webm|Pattern Formation from Blue Bottle Experiment in Warm Water Bath Time-lapse File:Pattern Formation from Blue Bottle Experiment in Warm Wate.jpg|Pattern Formation from Blue Bottle Experiment in Warm Water Bath File:Chemical Traffic Light Experiment Pattern Formation In Different Shape Containers.webm|Chemical Traffic Light Experiment Pattern Formation In Different Shape Containers Time-lapse File:Chemical Traffic Light Experiment Pattern Formation In Different Shape Containers.png|Chemical Traffic Light Experiment Pattern Formation In Different Shape Containers </gallery>
A group of researchers of the University of Glasgow named Pons, Batiste and Bees came up with a small conclusion about pattern formation in the methylene blue-glucose system. They came up with a conclusive statement that a similar pattern can be formed in a container with accessible oxygen. This resulting surface tension effect isn't required to produce the instability. Small holes were also found in the lid of container that oxygen can't access resulting in a thin, blue, and lower amount of oxygen. Pattern length and time scale had been explored in one of their experiments due to the variation in viscosity and fluid depth. The experiment reveals that the wavelength is formed as a pattern starts to form quickly. Then wavelength or pattern can be maintained or oscillate for a while.<ref>{{cite journal |last1=Pons |first1=A. J. |last2=Batiste |first2=O. |last3=Bees |first3=M. A. |title=Nonlinear chemoconvection in the methylene-blue–glucose system: Two-dimensional shallow layers |journal=Physical Review E |date=2008 |volume=78 |issue=1 |article-number=016316 |doi=10.1103/PhysRevE.78.016316|pmid=18764059 |bibcode=2008PhRvE..78a6316P |hdl=2445/18933 |hdl-access=free }}</ref>
==References== <references/>
== External links == {{Commons category|The blue bottle experiment}}
{{DEFAULTSORT:Blue Bottle (Chemical Reaction)}} Category:Chemistry classroom experiments Category:Clock reactions Category:Pattern formation Category:Articles containing video clips