1. Abstract
We report our investigations on the form and behavior of droplets and jets.
An antibubble is a liquid-droplet which is surrounded by the thin film
of air. Antibubbles can be formed in water, silicone oil, ethylene glycol,
etc. Thin film of air is stable when the liquid is moving. And we found
experimentally that water bounce off the surface of water, when we pour
a thin stream of water.
Keywords: Antibubble, Bouncing Jet, Surfactant, Surface Tension
２．実験および結果
【実験１】Antidomeの構造を調べる
水道水100mLに洗剤5滴の割合で溶かした洗剤溶液（これ以降、洗剤溶液という用語はこの溶液を意味する）を調製し、ストローに含ませた洗剤溶液を、溶液表面に置くように乗せてAntidomeをつくり、横、上、斜め上の３方向から高速度カメラ（Kodok Motion Corder Analyzer Model SR-Ultra）で撮影した。撮影速度は1000fpsとした。
写真1,2から、Antidomeは上方が水平円形で、下方が球面状の半球形をしていることが分かった。半球形の周囲には暗い縁が形成されていた。写真3から、液滴と洗剤溶液の間には隙間があり、この隙間は大気と繋がっていることが分かった。上面の半径は約10mm、半球の高さは約4mmであった。しかし、Antidomeは2秒以内で崩壊した。周囲に暗い縁が観察されたことから、全反射を起こす気液界面が存在し、気体は空気であると予想される。従って、Antidomeは半球状の溶液を空気薄膜が支えている構造であると考えられる。
【実験2】Antidomeの崩壊過程を調べる
Antidomeをつくり崩壊の様子を横および上の２方向から高速度カメラで撮影した。撮影速度は1000fpsとした。
横からの映像（写真4）では、液滴周囲の暗い縁のうち左側の縁が薄くなった後消え、さらに左側から右側へ向かって消えていった。暗い縁が存在した部分には数個の気泡が観察された。崩壊時間は0.038秒であった。上からの映像（写真5）では、円形の暗い縁の一部（図中では下側）が消え、さらに下側から上側に向かって消えていった。最後に消えた部分および円形の内側部分に、数個の気泡が観察された。崩壊時間は0.026秒であった。
【実験3】Antidomeを鉛直加振してその挙動を調べる
洗剤溶液を入れた容器を加振装置（EMIC製 VIBRATION GENERATOR MOOEL 513-B）に固定し（写真6）、Antidomeをつくると同時に鉛直加振した（図3）。加振条件は（a）振動数1Hz、振幅4㎜の矩形波、（b）振動数2Hz、振幅4㎜の矩形波、（c）振動数3~10Hz、振幅4㎜の矩形波、（d）振動数2Hz、振幅4㎜の正弦波の4通りとした。結果は表1のとおりであった。
振動数が1Hzの矩形波で加振しても、崩壊までの時間は自然な崩壊時間（2秒以下）であったが、2Hz～10Hzでは10倍～100倍の時間崩壊しなかった。2Hzの場合、上から見るとAntidomeはほぼ同じ位置に止まり、形は少しゆがむ程度であった（写真7）。2Hzの矩形波で加振していると、ふたつのAntidomeが接近して合体する現象が観察された（写真8）。2Hzの正弦波で加振した場合、矩形波の場合と異なり自然な崩壊時間（2秒以下）で崩壊した。振動数を上げていくとAntidomeは、激しく揺れ形を歪めたが崩壊しなかった（写真9）。約8Hzでは２つの形が交互に入れ替わる変化が現れた（図4）。
【実験4】洗剤溶液を水平方向に揺さ振りAntidomeの挙動を調べる
Antidomeをつくり、直後にストローでAntidome付近の溶液を水平方向に揺さ振り続けた。揺さぶりの幅は2cm程度、振動数は2～3Hz、ストロー（外径4mm）の水中に入る部分は1cm程度とした。Antidomeの挙動を横、上、斜め上の３方向から高速度カメラまたはデジタルカメラで撮影した。高速度カメラの撮影速度は1000fpsとした。
ストローで洗剤溶液を揺さ振ると、Antidomeは自然な崩壊時間である2秒をはるかに超えて分のオーダーまで崩壊せず（最長4分45秒）、形が歪んでも、器壁に接触しても崩壊しなかった（写真10,11,12）。周囲の暗い縁の一部が狭くなったり、水に被われたりするが崩壊しなかった。水に被われている時間は0.02～0.1秒であった。
【実験5】Antidome およびAntibubbleを分割する
Antidomeをつくり、ストローを動かしてAntidome周辺の溶液を揺さ振り、水面に対して垂直に立てたストローで揺れ動いているAntidomeを切るとAntidomeをふたつに分割させることが出来た（写真13）。
Antibubbleをつくり、ストローをゆっくり近づけAntibubbleを切ろうとしたが、ストローがAntibubbleに接触した瞬間Antibubbleが崩壊した（写真14）。一方、ストローを動かしてAntibubble周辺の溶液を揺さ振り、揺れ動いているAntibubbleをストローで切ったところふたつに分割できた（写真15）。
【実験6】Antibubble形成に対するイオンの影響を調べる
純水を用いて濃度が３mol/L 、 1.5mol/L、0.75mol/Lの塩化ナトリウム水溶液と塩化カルシウム水溶液を調製し、それぞれに洗剤5滴を滴下して混合した後、Antibubbleの形成を試みたところ、表2のような結果を得た。
200mLビーカー中に濃度が、3mol/L、1.5mol/Lの塩化ナトリウム水溶液および塩化カルシウム水溶液をつくり、それぞれに非イオン性界面活性剤であるTritonXを0.3mLずつ滴下した後、Antibubble形成を試みたところ、すべての場合についてAntibubbleが形成された。
【実験7】飽和食塩水に界面活性剤の量を増やしていくとAntibubbleやAntidomeの形成がどう影響を受けるかを調べる
50mLビーカーを２個（A、B）用意し、それぞれに飽和食塩水50mLを入れ、ビーカーAには洗剤を、ビーカーBにはTritonXを滴下してAntibubbleとAntidomeの形成を試みた。洗剤を追加して形成の変化を調べた。結果は表3、表4のとおりであった。洗剤の追加にともなってストローから落ちた液滴が水中深く沈んで行かず、弾力性のあるゴムマリのように水面へもどり、Antidomeになる場合が多く観察された。また、液滴がいったん沈んでAntibubbleを形成した後、浮かんで来て Antidomeになる現象も観察された（写真16）
３．考察とまとめ
(1)液滴がストローから水面に落ちるとき、液滴表面に付着した空気がそのまま液滴を包み込んで水中に没するとAntibubbleが形成されるが、液滴が水面に到達したとき、その速度が小さいと液滴は水中に没することが出来ず、付着した空気層上に乗りAntidomeが形成される。Antidomeの空気薄膜が2秒間存在できる理由は、界面が引き伸ばされると界面活性剤の面積密度が減少して界面張力が増大し膜厚をもとに戻す力が働くこと、界面活性剤の添加により溶液の粘性が増大して界面付近の空気が動きにくくなっていること、空気薄膜では境界層が接近しており空気が動きにくい状態にあることだ考えられる。加振や揺さ振りによって空気薄膜の変形が速いと薄膜を形成している空気の粘性が大きくなり、空気の流動性がさらに減少する。
Antidomeが崩壊するときは、空気は縁全体から均等に流出するのではなく、縁の一部が水に閉じられると、閉じられた部分の反対側に薄膜層の空気が集まっていくことが実験から分かったが、その崩壊時間0.03～0.04秒が、Antibubbleの崩壊する時間0.02～0.03秒とほぼ等しいことは、空気が均等に流出するのではなく、一方向への収束であることと関連していると思われる[1]。また、溶液を揺さ振っている際、大気連結部分の一部が水に被われて復元するまでの時間が0.02～0.1秒程度であったことから、溶液の揺さ振りでAntidomeが崩壊しにくい理由は、洗剤溶液の粘性や界面張力に加えて薄膜内の空気が変形を受けて粘性を増し、被われている時間が0.1秒以下では空気流出が起きないことだと考えられる。
(2)2Hzの矩形波で鉛直加振した場合にAntidomeが崩壊しない理由は次のように考えられる。空気薄膜の厚さがマイクロメートル程度の薄さであることに加えて薄膜への圧縮が急なため空気の粘性が効くこと、および洗剤添加のため溶液の粘性が大きくなっていることによって空気は逃げずつぶれず液滴を押し上げる。次に、半球形の溶液水面が急に下降しても液滴は慣性のためすぐには落ちて来ない。薄膜の膜厚が広がって低圧となり、大気中から空気が流れ込み、ワンテンポ遅れて落ちて来る液滴を支える。以下、この現象が繰り返される。矩形波によって空気薄膜が急速に圧縮されるために空気の温度が上昇し粘性が大きくなることが効いているかも知れない。2Hz正弦波は圧縮がゆっくりであること、1Hz矩形波は加振の停止時間が長いことにより2秒以内に崩壊すると考えられる。
(3)溶液を揺さ振っているときにAntidomeやAntibubbleをふたつに分割出来たことは、空気が気泡にならず薄膜状態を維持出来たことであり、変形を受けている薄膜中の空気が流動しにくいことを示唆している。
(4)溶液中に陽イオンが存在すると、界面活性剤分子が親水性部分をイオン側に向けて集合するため、Antibubbleの形成にかかわる界面活性剤分子の数が減少して空気薄膜が形成されないと考えられる。洗剤の追添加によってAntibubbleは形成されるようになる。
TritonXを用いた実験6において、全ての場合についてAntibubbleが形成された理由は、TritonXが非イオン性のため溶液中のイオンとの親和性が低いためTritonX分子が溶液中のイオンを取り囲むことはわずかで、空気薄膜を維持するのに必要な量のTritonX分子が薄膜界面に並んだと考えられる。
(5)実験7においてAntibubbleが沈みにくいことやAntibubbleよりもAntidomeの方が形成されやすいことの原因としては、通常滴下する洗剤の4倍～10倍量を滴下しているので溶液の粘性が増大していること、付着する空気量が変化していること、イオンと界面活性剤が特殊な構造をとっていることなどが考えられる。通常Antibubbleは水面下にしばらく停留した後、瞬間的に崩壊して空気薄膜は気泡になる。しかし、実験7で見たように、AntibubbleがAntidomeを経てから崩壊する現象をたびたび観察した。この現象を理解するには、イオンや界面活性剤の濃度や溶液の粘性の影響および溶液内部や水面のようすを検討するとともに、Antibubbleの周囲が溶液であるのに対してAntidomeの周囲は溶液と大気であること、またAntidomeの表面積がAntibubbleの約1.2倍あることから、界面への界面活性剤分子の並び方がどう組み変わるのかについても検討する必要があると考えられる。
**************Under Construction****************************
1. Introduction: What is an antidome ?
An antidome is the opposite of a bubble-dome.
2. Experiment 1: How do we make an antimome ?
*****************
Antibubbleの復習
The formation,collapse, behavior of Antibubbles
[firstly] with Antibubble
Antibubble is reverse of Bubble (soap bubbles). A liquid film surrounds air in Bubble, and the outside is air. A film of air surrounds liquid in Antibubble, and the outside is liquid.
[experiment 1] I make Antibubble
[preparations] City water, detergent (LION ), a straw, a beaker
[a method]
1. I put city water of 100mL within a beaker, and a drop sets five drops of detergent (LION ) on this and I stir it not to bubble and prepare the same detergent solution.
2. I pay you 2cm for a straw within two detergent solution and block up the other side of a straw with a finger.
3. I hold a straw to 5mm on the increase surface of the water from the water and separate the finger which blocked up the other side (figure 1)
[experiment 1]
Result 1.
The detergent solution of straws became a liquid drop by method 3 and was in the solution of beakers (figure 2). A dark relationship was formed to circumference of the liquid drop which became global then (figure 3). Stopped by a drop and rose slowly and stopped for a while right under the surface of the water after having dropped in the whole solution for a while without a liquid drop being mixed with the solution of beakers with it having been surrounded on a dark border (figure 4). A dark relationship collapsed instantly in approximately 1 minute, and the detergent solution was mixed with solution of circumference afterwards. When I did not collapse for 7-18 minutes, I met.
Result 2.
A color such as a rainbow was observed on the surface of detergent solution (I call it Antibubble as follows) surrounded by a dark edge (figure 5).
Result 3.
I was thin at the lower part, and the dark relationship of circumference was seen thick at the plumb upper part when I observed Antibubble from the side.
Result 4.
Antibubble which collided on the side of a beaker bounced without collapsing, but Antibubble which arrived at a bottom of a beaker collapsed the moment that collided at a bottom.
Result 5.
When it collided at a bottom in the solution inside even if I put it right under the surface of the water, the moment that collapsed, an air bubble small above of Antibubble were observed.
Result 6.
When it was gentle, and Antibubble collided from the side, I bounced like a rubber ball, and neither Antibubble collapsed. When it collided on the beaker side, it was often observed when I bounced without collapsing.
[experiment 1] consideration
Consideration 1.
Because a color was observed on the surface of Antibubble by result 2, the surface of Antibubble understands that there is a film of degree to let interference of light occur. It seems that this film is the atmospheric layer which stuck to the surface when detergent solution dies underwater.
Consideration 2.
It shared it that there was comparatively the gas that became a film by result one or two for stability underwater. In addition, the cause why Antibubble rose to is thought about as follows. Because solution in Antibubble and solution of circumference are the same solution, specific gravity is the same. However, as for the inner liquid, specific gravity of the part which I included to an atmospheric layer is smaller than solution of circumference so that it is surrounded circumference in a thin atmospheric layer. On this account Antibubble rises.
It is thought that a cause of 3. consideration results 3 is to stabilize a plumb in Antibubble by gravity heartily at the position that I was out of a little underneath.
As for the cause of 4. consideration results 4, in the thin atmospheric layer surrounding inner liquid, it is expected that it is unstable for pressure, but it seems that the reason is because it is easy to collapse because a part of the lower part is the thinnest.
A film of air tear 5. consideration results 5 in the side that thickness is light, and it is thought that it is drawn into the side that thickness is thick and became an air bubble.
Consideration 6. Liquid is to loosen in the air among Antibubble, but this is so that gravity and buoyancy by air to commit match with inner liquid. Therefore, it seems that pressure of an atmospheric layer is big small at the lower part at the upper part.
An atmospheric layer (a film) of 7. consideration Antibubble compares it, and the cause that is stability is thought about as follows. When Antibubble was formed, a surface active agent molecule applies a hydrophilic part to the solution side in a part channeling-related in the atmospheric layer side and lines up in an interface (figure A). When an atmospheric layer is enlarged for some causes, the density of a surface active agent molecule of an interface falls (figure B). As a result, surface tension of an enlarged part increases and pulls back the air film which lengthened. Thickness of an atmospheric layer is kept a fixed in this way, and there is comparatively Antibubble for stability.
[experiment 2] the measurement [a policy]
I sample air forming a film and measure the volume (to inspect
consideration 1 of experiment 1).
[preparations]
City water, detergent (LION ), a straw, a beaker, a method of a measuring cylinder [experiment 2]
I do it same as experiment 1 and make Antibubble.
I sample a careful bubble to occur when Antibubble collapses to a
measuring cylinder by water substituting (figure 6, figure 7).
I sample an air bubble of Antibubble100 to one measuring cylinder (figure 6, figure
7).
I measure a volume of the gas that I sampled in .
I measure a radius of Antibubble.
[experiment 2]
I was able to sample gas by collapse of 100 Antibubble
(figure 7).
The volume of the gas that I sampled was 285mm 3.
The average radius of Antibubbie was 6.6mm.
[experiment 2] consideration
When I assume d, a volume v in r, at a radius of Antibubble,
4π r2d = v .
Substitute r =6.6mm, v =2.85mm 3 from an experiment result
d =5.2 μ m .
As a result, Antibubble could confirm that it was surrounded by an air film of μ m order, and it shared it that this air film caused buoyancy and an expression.
[experiment 3] I examine a process of collapse [a policy] I photograph the state that Antibubble collapses with a high speed camera (to inspect consideration 5 of experiment 1).
[preparations]
City water, detergent (LION ), straw, corner type water tank, illumination device, enamel Line, high speed camera (Kodak Motion Corder Analyzer, Model SR-Ultra)
[experiment 3] a method
1. I make Antibubble in a corner type water tank (figure 8).
2. I stab the top surface of Antibubble stopping in surface of the water bottom, a lower part, the side in enamel Line and photograph the state that Antibubble collapses with a high speed camera. I made the photography speed 1000fps (figure 9).
[experiment 3]
1. The state of collapse came as I showed it in figure 10,11,12. In addition, the photograph arranged a state before collapse, a collapsing state, states after collapse in chronological order.
2. The time before a film of air completely becoming extinct from the moment when I stabbed with enamel route was 0.026 seconds (top surface splinter), 0.016 seconds (a lower part splinter), 0.016 seconds (a side splinter).
[experiment 3] consideration consideration 1.
Gas gathered to the other side of the part which they were stabbed in, and a film shrank and became extinct, and a big air bubble and a small air bubble occurred. According to air bubble being stability, this is thought about than a film. It seems that the reason why a lot of careful air bubbles occurred is because I was not able to finish being gathered up in a big air bubble because shrinkage speed of a film is fast.
Consideration 2.
(when I stabbed a lower part) one big air bubble occurred in the vicinity of the top surface and dropped after film extinction temporarily. It is thought that this is because gas was easy to be unified in one so that a direction of buoyancy accords with a direction of the shrinkage (figure 10).
Consideration 3.
(when I stabbed the side) the film shrank in the other side of the side that I stabbed, but the big air bubble was formed in the vicinity of the upper part of Antibubble. It seems that atmosphere of a film depends on influence of buoyancy by a gathering process (figure 11).
Consideration 4.
(when I stabbed the top surface), by the process when a film shrank, ten comparatively big air bubbles appeared on the way, and a careful air bubble occurred. It is thought that that I become one air bubble was disturbed by resistance and buoyancy. In addition, it seems that time to take by film extinction is a reason to be similar most for a long time (figure 12).
Consideration 5.
I was able to inspect consideration 5 of experiment 1 by consideration as a result of above. Furthermore, it shared it that result one of an air bubble had a difference (statement above) by the direction where a film shrank.
[experiment 4] I make Antibubble which does not rise [a policy]
I mix show sugar with solution of Antibubble and make specific gravity big (to get collaborating evidence about consideration 2 of experiment 1).
[preparations]
10% show sugar water, city water, a straw, a beaker, a detergent (LION ) [experiment 4] method
1. A drop sets four drops of detergent on city water 100mL in a beaker and mixes it.
2. I put 10% show sugar water 100mL within another beaker and a drop gives four drops of detergent to this and mixes it.
I soak a straw with 3.2 solution and make Antibubble within one solution.
[as a result of experiment 4] result 1.
Formed Antibubble sank into the bottom slowly and did not rise (figure 13).
Result 2.
Antibubble collapsed suddenly in a few minutes. Collapse was caused from a lower part of Antibubble, and a careful bubble appeared in the vicinity of the top surface.
[experiment 4] consideration
Consideration 1.
It is thought that the reason why Antibubble was sunk in is because specific gravity of the whole Antibubble including an air film grew bigger than specific gravity of outside liquid because I let show sugar dissolve.
Consideration 2.
According to the thinness of an air film, the reason why collapse happens from a lower part seems same as consideration 4 of experiment 1.
[experiment 5] I make Antibubble which rises after I am depressed once, and having stopped [a policy]
It is assumed that sunk Antibubble rises if I mix solution occurring by gas slowly with inner liquid. I use the BZ reaction solution which department of principal school science studied before and generate gas slowly.
[preparations]
Marron acid, bromic acid sodium, sodium, sulfuric acid, 1,10-phenanthoroline, sulfuric acid iron, pure water, detergent (LION ), a beaker, a glass stick, an electronic balance
[experiment 5] a method
1. I dissolve the next chemical reagent in pure water 100mL and prepare solution A~E.
(A liquid) sodium bromate12.5g
(B liquid) sodium bromide 2.5g
(C liquid) malonic acid 2.5g
(D liquid) sulfuric acid 17mL
(E liquid) 1,10-phenanthoroline 1.35g, sulfuric acid iron (Ⅱ) 0.7g
2. I put A liquid 20mL, B liquid 10mL, C liquid 20mL, D liquid 10mL within a 100mL beaker, and liquid color shakes a beaker from yellow till I become colorless.
3. I put two solution 6mL and E liquid 1mL in pure water 93mL and stir it calmly, furthermore, a drop sets four drops of detergent (LION), and not to bubble.
4. I prepare the solution which mixed eight drops of detergent in pure water 200mL for a 200mL beaker.
I take 5.3 solution to a straw and make Antibubble within four detergent solution.
[as a result of experiment 5] Antibubble showed three kinds of next behavior.
1. result Antibubble was sunk to a bottom of a beaker and collapsed at the same time to collide in a base.
2. result Antibubble was sunk to a bottom of a beaker and collapsed after having stopped at the position for around 1 minute (figure 14).
It began to rise slowly and collapsed after 3. result Antibubble stopped in the middle of detergent solution for a while before arriving at the surface of the water (figure 15).
[experiment 5] specific gravity of inner liquid becomes bigger than specific gravity of outside liquid, and it is thought that therefore Antibubble set so that a material such as bromic acid sodium melts to liquid in 1. consideration consideration Antibubble.
Consideration 2.
I can explain a phenomenon of result 3 as follows.
The following chemical reaction happens by the material which I dissolved in inner liquid.
3BrO3 - +5CH2(COOH)2+3H+
→ 3BrCH(COOH)2+2HCOOH+4CO2+5H2O
Carbon dioxide of gas occurs by this reaction. This carbon dioxide enters within a film of Antibubble, and volumes of a film increase.
As a result, specific gravity of Antibubble shrinks than specific gravity of outside liquid, and Antibubble begins to rise. A rise is in the way, and, as for what collapsed, it is thought that a film became unstable because quantity of gas exceeded a certain price.
[experiment 6] I examine influence of a supersonic wave for Antibubble [a policy] I try to use a supersonic wave as one of the methods to examine stability of an air film (to inspect consideration 4 of experiment 1).
[preparations]
City water, detergent (LION ), a straw, an inder, supersonic wave outbreak device
[experiment 6] a method / a result / consideration
[a method]
1. I dissolve four drops of detergent in city water 100mL and prepare detergent solution.
2. I put detergent solution in an inder and soak this inder into the water of supersonic wave outbreak devices.
3. A drop gives detergent solution from a straw and makes Antibubble.
4. If Antibubble was formed, I generate a supersonic wave.
[a result] Antibubble collapsed with outbreak of a supersonic wave from bottom.
[consideration] A film of Antibubble vibrated, and a suggestion of a sharp thing was provided for pressurization.
[experiment 7] I make Antibubble which I range in the letter of Rosary (beads), and is made
[preparations]
City water, detergent (LION), a beaker, a washing bottle, copper wire, scissors
[experiment 7] a method
1. It cuts a nozzle part of a bottle with scissors to become 3mm inside diameter.
2. I prepare detergent solution same as experiment 1 and put it in a beaker and a bottle.
3. Several times surround copper wire on a nozzle part and soak the one end into the solution of beakers.
I bring a nozzle close to the surface of the water with having kept 4.3 states and begin to drain the solution of bottles (figure 16).
[as a result of experiment 7] 1. result continuation style was narrow, and plural Antibubble was formed.
The phenomenon that solution was carried on on 2. result surfaces of the water was observed.
[experiment 7], on the occasion of 1. consideration consideration Antibubble formation, there is the indication that a potential difference of inner liquid and outside liquid influences, but it suggests the propriety of this indication that continuation style is narrow by this experiment, and plural Antibubble was formed.
There are dome-shaped soap bubbles (the chart below left) on 2. consideration surfaces of the water, but dome-shaped Antibubble (the chart below right) is done unless it is possible. However, it seems that result 2 suggests the possibility that dome-shaped Antibubble (I call it Antidome) can make by devising an experiment condition.
[experiment 8] I try the Antidome formation
[preparations] City water, detergent (LION), a straw, a method of a square shape water tank [experiment 8]
1. When I drop solution from a straw, it is gentle and drops it to put it on the surface of the water.
2. On Antibubble stopping in surface of the water bottom, I drop detergent solution from a straw.
[as a result of experiment 8] reproduction characteristics were good, and, by 1. result methods 1, lens-shaped Antidome was formed on the surface of the water for two seconds (figure 17, figure 18).
The solution which I dropped by 2. result methods 2 was united with Antibubble, and lens-shaped Antidome was formed for two seconds.
When 3. result Antibubble surfaced from the water and arrived at the surface of the water, the phenomenon that liquid in Antibubble was carried on on the surface of the water was observed for a short time.
[experiment 8] it seems that 1. consideration consideration results 1 is because there was the liquid drop which I put on the surface of the water on the atmospheric layer which stuck to a liquid drop lower part for two seconds.
When the detergent solution which I dropped from a straw collapsed in Antibubble under the surface of the water, liquid is united among solution and Antibubble which I dropped, and 2. consideration results 2 gets on the air film which made Antibubble, and it seems that the state was kept for two seconds.
Because an air film of bottom supported a liquid drop when Antibubble surfaces as for 3. consideration results 3 from the water and arrived at the surface of the water even if an air film of the Antibubble upper part is torn, it is thought that I formed Antidome on the surface of the water for a short time.
[at the end] main result of this study is four points of next.
1. I get possible to make Antibubble surely.
2. I measured thickness of an air film and I was accompanied and stopped a principle and a cause of a color to loosen.
3. I photographed a process of Antibubble collapse with a high speed camera and clarified the characteristic.
4. I developed a method to control ups and downs of Antibubble.
5. I discovered existence of an anti-dome (Antidome) and succeeded in making it.
[an impression and a problem]
I saw Antibubble for a
simple phenomenon, but there was various discovery when I tried to test it, and
doubt was heated in sequence. I hypothesized based on them and I could wrestle
with an experiment immediately and was lucky. Because I came across a phenomenon
suggesting electrical current potential to solution and influence such as
temperature while I wrestle with an experiment, I want to examine it about
these. In addition, I want to wrestle with the formation of longer time existing
Antidome.
References
E.Niida, M.Hamada, M.Fujishima, "Proceedings of 50th Japan Student
Science Award", The Yomiuri Shinbun(2007)