香蕉皮的新生命——生物塑料

Marco： Our next story is about a different sort of challenge， though it still involves finding better ways to use our natural resources. Sixteen-year-old Elif Bilgin from Istanbul， Turkey， wanted to find an alternative to traditional petroleum-based plastic production. She came up with a way to develop a bio-plastic from， get this， discarded banana peels. Her project won a 2013“Science in Action” award and a $50，000 prize from Scientific American. So how’d you come up with this idea， taking bananas and turning them into bio-plastic？

Elif： I read a paper about how to make bio-plastic out of potatoes and the 1）starch that was extracted from that， and I thought maybe I could find another substance that I could use to make a plastic， which was not something we consume every day but actually we throw away every day， and the banana peel was a really good example for that.

Marco： So how do you do it？ How do you take this banana peel and get the starch out of it and turn it into plastic？

Elif： I actually just take the banana peel and then dip it into a special solution， which has some chemicals in it—it’s called 2）sodium metabisulfite solution—and then I boil the banana peels， and then actually mash them into some sort of a 3）puree or paste. And then I take 25 millilitres of this paste， add sodium 4）hydroxide and 5）hydrochloric acid and also 6）glycerin， and then I bake it and it becomes plastic.

Marco： And you did this， like， in your Mom’s kitchen or something？

Elif： I did part of it in my Mom’s kitchen， part of it at the laboratory， and， well， that was it.

Marco： And， like any good scientist， you had to experience the disappointment of trial and error， but you finally landed on a formula that lasts for a while. Can you take banana plastic and turn it into an everyday item， for example， plastic water bottle. Are you there yet？

Elif： I didn’t try with water bottles but I actually 7）insulated a copper cable，…

Marco： Wow！

Elif： …and also， if you bake it into a mold it can be actually used in the making of cosmetic 8）prostheses.

Marco： And how long does this plastic last， ’cause I know some plastics， they get a little 9）brittle after a while， they fall apart. What’s the duration on your plastic？

Elif： I’m not sure exactly because， it’s a funny story， I didn’t think that I was gonna be chosen， so I threw the plastics away after， like， three months， so I’m not really sure， but it stays 10）intact for a long time.

Marco： Right. It lasted long enough for you to get the prize from Scientific American. You know， just the other day I was wondering about plastics—I wonder about things like that—and was really surprised to find out that plastics actually pre-date mass fossil fuel use by centuries. Like， even in the Middle Ages， they were making plastics out of bio-proteins like blood and egg yolk. So are you reclaiming the plastics of years past？

Elif： Well， we polluted the Earth long enough and I think we should go back to the old way， so we can actually reclaim a part of it.

Marco： So， you…you won $50，000 for this. What are you gonna do with the prize money？

Elif： I’m not sure， but my main focus will be to further develop my project.

Marco： Keep on working with banana peel plastics， bio-plastics？

Elif： Yeah.

Marco： Elif， I’m…I’m just curious how a…a 16-year-old young woman got into experimenting with plastics， when I’m sure a lot of other people around you are more interested in who the latest pop star is and…

Elif： Yeah， Justin Bieber.

Marco： …where Justin Bieber’s flying next.

Elif： Yeah. Well I really love science and I’ve been attending a school for gifted students for the last six years， and they support you a lot and encourage you to do scientific research， and I’ve been in that program for six years， and I’ve been very interested in science.

Marco： What do you think the big oil companies will have to say about banana peel plastics？

Elif： Oh my， I’m not sure.

Marco： Sixteen-year-old Elif Bilgin from Istanbul， who’s won the 2013 “Science in Action” award.

馬可：同樣是關于如何更好地利用自然資源，我們的下一個故事可以說是另一種挑戰。來自土耳其伊斯坦布爾的16歲女孩艾利芙·比爾金希望能找到一種新的方法來替代靠石油制造塑料的傳統方式。最終，聽好了，她想出了利用丟棄的香蕉皮制造生物塑料的方法。她因此在2013年贏得了由《科學美國人》贊助的“科學在行動”獎并獲得五萬美元的獎金。你是怎么想到用香蕉的皮制造生物塑料這個點子的？

艾利芙：我曾讀到一篇論文講的是利用土豆，從土豆中提取出淀粉來制造生物塑料。所以我想也許我能找到另一種物質—— 一種我們每天丟棄而不是每天消耗的東西，來制造塑料。香蕉皮就是這樣一個好例子。

馬可：那具體是如何操作的呢？你是怎么將香蕉皮中的淀粉提取出來并將之變成塑料的呢？

艾利芙：我就是將香蕉皮浸泡在一種含化學物質的特殊溶液——焦亞硫酸鈉溶液中，然后將它煮沸并搗碎成泥狀或糊狀物。取25毫升這種泥狀物，加入氫氧化鈉、鹽酸和甘油，再拿去烘烤，它就變成塑料了。

馬可：這么說，你像是在媽媽的廚房之類的地方完成這些步驟的？

艾利芙：確實有一部分是在媽媽的廚房里進行的，而剩下的得在實驗室里完成。嗯，沒錯，就是這樣。

馬可：像所有成功的科學家一樣，你一定也經歷了反復試驗失敗的那種挫敗感，但你最終找到了比較穩定的配方。你能將這種香蕉塑料用于我們日常用品的制作嗎？比方說塑料水瓶，你走到那一步了嗎？……