演讲题目：What happens if you eat a silica gel packet?

演讲简介：

在众多我们不该拿来当零食吃的东西里，也许最常见的“违禁食品”就是硅胶干燥剂了。这种小包装出现在各种产品的包装中——从电视机、吉他盒，到防晒霜和零食袋里。那么，为什么硅胶干燥剂无处不在？如果真的吃了它，又会发生什么呢？Vivian Jiang深入探讨了这种无处不在的产品的科学原理。



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Of the many, many things we're not supposed to snack on, perhaps the most common forbidden food is silica gel.

在我们不应该吃的很多东西中，也许最常见的违禁食物是硅胶干燥剂。

This tiny packet pops up in packaging for everything: from TVs and guitar cases to sunscreen and snack foods.

这个小包裹会出现在所有东西的包装中：从电视和吉他盒到防晒霜和零食。

So why is silica gel everywhere, and what would actually happen if you ate it?

那么为什么硅胶干燥剂无处不在？如果你吃了它，实际上会发生什么？

Found in the Earth's crust, silica, also called silicon dioxide, is typically mined as raw silica sand, which is then washed, dried, sifted, and chemically treated.

硅胶（也称为二氧化硅）存在于地壳中，通常作为原硅砂开采，然后进行清洗、干燥、筛选和化学处理。

Once manufacturers ensure each grain is uniform, the processed sand gets mixed with sodium carbonate, then heated and combined with an acid that links the silica particles into a jelly-like matrix.

一旦制造商确保每个颗粒均匀，处理后的沙子就会与苏打混合，然后加热并与酸混合，将二氧化硅颗粒连接成果冻状的矩阵。

This matrix gives the material its porous structure, which stays stable after being washed and dried into hard, glassy beads.

这种矩阵赋予材料以多孔结构，在清洗和干燥成坚硬的玻璃状珠子后保持稳定。

The final product is chemically identical to the sand you might find on a beach.

最终产品的化学成分与您在海滩上找到的沙子相同。

The only difference is that porous structure.

唯一的区别是多孔结构。

Inside each silica gel bead is a massive microscopic network of tunnels.

每个硅胶珠内部都有一个巨大的微观隧道网络。

This dramatically increases the surface area of each bead, with a single gram of silica offering over 700 square meters of surface area.

这大大增加了每个珠子的表面积，每克二氧化硅的表面积超过700平方米。

But this space doesn't stay empty for long.

但这个空间不会空太久。

The silicon dioxide molecules that make up the gel are held together by polar covalent bonds, which attract other polar substances, including water.

构成凝胶的二氧化硅分子通过极化键固定在一起，从而吸引包括水在内的其他极化物质。

So when silica gel is placed in a humid environment, the water in the air is drawn to the beads' surface.

因此，当硅胶放置在潮湿的环境中时，空气中的水会被吸引到珠子的表面。

From these surface pores, the water vapor is then pulled inside the grain through a process called capillary condensation.

从这些表面孔隙，水蒸气然后通过一个称为毛细冷凝的过程被拉入谷物内部。

Each grain can hold up to 40% of its own weight in water, allowing a standard 5-gram packet to hold roughly 2 grams of liquid.

每粒谷物在水中最多可容纳其自身重量的40%，因此标准的5克包装可容纳大约2克液体。

And since this liquid is held inside the bead's internal network, even fully saturated silica doesn't feel wet to the touch.

由于这种液体被保存在珠子的内部网络内，即使是完全饱和的二氧化硅摸起来也不会感觉潮湿。

This ability makes silica gel a desiccant, a type of substance used to keep things dry.

这种能力使硅胶成为干燥剂，一种用于保持物品干燥的物质。

But these beads can suck up more than just water.

但这些珠子能吸收的不仅仅是水。

Silica attracts ammonia, sulfur dioxide, and a handful of other gases, making it useful in gas masks and other filtration systems.

二氧化硅可以吸引氨、二氧化碳和少数其他气体，使其可用于防毒面具和其他过滤系统。

The pace of this process depends on the environment.

这个过程的速度取决于环境。

In a very humid enclosed space, a packet could reach its saturation point within a day or two, but this could take up to a week in a moderately humid environment.

在非常潮湿的封闭空间中，一个包裹可能会在一两天内达到饱和点，但在中等潮湿的环境中，这可能需要长达一周的时间。

Either way, silica gel beads functionally last forever since you can dry them out in a hot oven.

无论哪种方式，硅胶珠在功能上可以永久保存，因为您可以将它们在热烤箱中晾干。

These abilities and silica's prevalence in Earth's crust have made it the planet's most popular commercial desiccant since we started mass producing it in 1919.

这些能力和二氧化硅在地壳中的普遍存在使其成为自1919年我们开始大规模生产以来地球上最受欢迎的商业干燥剂。

At home, it keeps snacks crispy and extends their shelf life, ensures pills and vitamins stay dry, and captures any stinky scents from your cat's litter box.

在家里，它可以让零食保持酥脆并延长保质期，确保药丸和维生素保持干燥，并捕捉猫猫砂箱中的任何恶臭气味。

Museums use silica gel in exhibit cases to prevent metal artifacts from rusting and preserved animals from growing mold.

博物馆在展品中使用硅胶来防止金属文物生锈，防止保存的动物长出霉菌。

And in outer space, a form of silica gel called aerogel is used to insulate rovers from extreme temperatures and capture high-velocity comet dust for study back home.

在外太空，一种名为气凝胶的硅胶用于使漫游车免受极端温度的影响，并捕获高速彗星尘埃供国内研究。

But what about what silica gel would do to you if you successfully swallowed a packet?

但是，如果您吞下一包硅胶会对您产生什么影响呢？

The answer is...not much.

答案是...不多。

Those "Do Not Eat" warnings have more to do with packets being choking hazards than any silica-specific concerns.

这些“请勿进食”警告更多的是与包装存在窒息危险有关，而不是任何针对硅胶的担忧。

Besides, your body has so much liquid in it, even if the packet did suck up the standard 2 grams, you could replenish that much and more with a single glass of water.

此外，你的身体里有很多液体，即使包吸了标准的2克液体，你也可以用一杯水补充那么多液体。

And since silica is chemically inert, your body won't break the gel down into something toxic.

由于二氧化硅具有化学惰性，因此您的身体不会将凝胶分解为有毒物质。

That said, downing larger quantities of silica gel would be unpleasant.

也就是说，服用大量硅胶会令人不舒服。

Its moisture-wicking properties could dry and irritate mucous membranes along the digestive tract, resulting in diarrhea and an upset stomach.

它的吸湿特性可能会干燥和刺激消化道的粘液，导致腹泻和胃部不适。

Worse still, some silica is coated with cobalt chloride to indicate moisture levels, and that compound actually is toxic.

更糟糕的是，一些二氧化硅表面涂有氯化钴以指示水分含量，而这种化合物实际上是有毒的。

But assuming your silica snack is of the standard variety, you should survive the ordeal.

但假设您的二氧化硅零食是标准品种，那么您应该能挺过这场磨难。

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