二氧化硅配方 - 结构、性质、用途、示例问题

二氧化硅，通常称为二氧化硅，是一种化学式为 SiO ₂的氧化硅，以石英的形式自然存在并存在于各种生物中。在世界许多地方，二氧化硅是沙子的重要组成部分。二氧化硅是一种矿物成分，也是一种合成产品，使其成为最复杂、最丰富的矿物类别之一。一些值得注意的例子包括熔融石英、气相二氧化硅、硅胶和气凝胶。它用于结构材料、微电子（作为电绝缘体）以及食品和药物成分。

什么是二氧化硅？

Silicon dioxide (SiO₂) is a covalent molecule with four oxygen atoms connected to each silicon atom and two oxygen atoms bonded to each silicon atom in a tetrahedral structure. Silicon dioxide has a large structure with an eight-membered ring produced by the arrangement of alternate oxygen and silicon atoms. 

采矿、采砂和石英提纯都是获得二氧化硅的方法。硅酸钠溶液的酸化产生沉淀二氧化硅或无定形二氧化硅。当硅胶经过漂洗和脱水后，形成无色微孔二氧化硅。因此，二氧化硅也被称为二氧化硅。

二氧化硅的制备

硅酸钠溶液的酸化产生无定形二氧化硅或沉淀二氧化硅。制作无色微孔二氧化硅，硅胶经过清洗和脱水。涉及三硅酸盐和硫酸的反应如下：

Na ₂ Si ₃ O ₇ + H ₂ SO ₄ → 3SiO ₂ + Na ₂ SO ₄ + H ₂ O

SiO ₂的结构

硅原子在大部分硅酸盐中呈四面体配位，四个氧原子围绕一个核心硅原子。结果，SiO ₂产生三维网络固体，其中每个硅原子以四面体方式共价连接到四个氧原子。 CO ₂是线性分子。碳和二氧化硅的显着不同结构证明了双键规则。

二氧化硅的性质

1. 二氧化硅可以是透明的到浅灰色的、结晶的、无味的或无定形的。
2. 这些材料的熔化和沸腾温度分别为 1713º C 和 2950º C。
3. 溶于氢氟酸，不溶于酸和水。
4. 由于分子的极性为零，二氧化硅不是一种非常活泼的化学物质。
5. 与氧一起，“Si”形成两个双键。因此，它是一种极其稳定的分子。
6. 它还具有高介电强度，可用作绝缘体和半导体。

二氧化硅的用途

• 在建筑领域，二氧化硅用于制造混凝土。
• 它的结晶形式用于水力压裂。
• 它用于生产玻璃。
• 它用作镇静剂。
• 它用于合成元素硅。
• 在香料等粉状食品中用作抗结块剂，在果汁、啤酒和葡萄酒中用作澄清剂。
• 用于牙膏中以消除牙齿上的牙菌斑。

Health Hazards of SiO₂

Silica is non-toxic when used orally. A 2008 study discovered that the higher the quantities of silica in water, the lower the incidence of dementia. As the risk of dementia decreased, the dose of silica in drinking water was increased to 10 mg/day. Inhaling finely divided crystalline silica dust can induce bronchitis, lung cancer, or silicosis due to dust lodgement in the lungs. When fine silica particles are inhaled in large quantities, rheumatoid arthritis and lupus become more prevalent.

示例问题

问题一：二氧化硅有什么用途？

回答：

The building industry accounts for approximately 95% of the industrial use of silicon dioxide (sand), for example, in the making of concrete (Portland cement concrete). Silica, in the form of sand, is utilised as a fundamental material in the production of metallic components in engineering and other sand casting applications. Because of silica’s relatively high melting point, it can be used in several applications.

问题二：二氧化硅是怎么产生的？

回答：

The majority of silicon dioxide is produced through mining activities such as sand extraction and quartz purification. Quartz is useful for a wide range of applications, but it may require chemical processing to produce a more suitable product (for example, more reactive or fine-grained), or to make it purer. As a byproduct of heated processes such as ferrosilicon manufacturing, silica fume is created.

问题3：二氧化硅有毒吗？

回答：

When taken orally, silica is largely non-toxic. Inhaling finely divided silica crystalline dust, on the other hand, may contribute to silicosis, bronchitis, or lung cancer because the dust becomes retained in the lungs and continuously irritates the tissue, reducing lung capacity.

问题4：二氧化硅的函数是什么？

回答：

Silicon dioxide can also be present in a number of other foods and supplements. It works as an anticlumping agent in food to keep clumps from forming. It prevents powdered ingredients from sticking together in supplements.

问题5：硅和二氧化硅有什么区别？

解决方案：

Silicon is a naturally occurring element. It is the element with the greatest abundance in the earth’s crust. It has both metal and nonmetal properties. Silicon dioxide is also known as silica. It is created by fusing silicon with oxygen. It is found in plants, water, the earth’s crust, and animals.