In the Beginning was the Deed
In the Beginning was the Deed
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起初是行为
DOI：
10.1007/978-3-642-71900-4_2
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发表时间：
1987
期刊：
影响因子：
--
通讯作者：
H. Elias
中科院分区：
文献类型：
--
作者：
H. Elias
偶然的观察、漫无目的的玩弄和系统的修修补补往往先于对现象的科学探索。橡胶、纤维和塑料的建筑元素--大分子也是如此：许多植物、灌木和树木在切割一种白色的牛奶状液体时会散发出液体，这种液体被称为乳胶(源自拉丁语“laex”=液体)。例如，我们房子里的橡胶植物，草地和草坪上的蒲公英。当接触到或多或少粘性的、有弹性的物质时，其中的一些乳胶凝结在一起，但空气实际上与此没有太大关系。胶乳是由微小的橡胶液滴(直径约0.0005-0.001毫米)在含有蛋白质、脂肪、碳水化合物、盐等的稀水溶液中形成的乳液。橡胶液滴的密度低于周围的水溶液。但由于“较轻”，它们漂浮到表面类似于未经巴氏灭菌的牛奶中的奶油(牛奶也是水乳状，尽管含有蛋白质和脂肪液滴)。然后，橡胶液滴开始粘在一起，当水蒸发时形成一层膜。
Chance observations, purposeless toying and systematic tinkering often precede the scientific exploration of phenomena. Such was also the case with the giant molecules, the building elements of rubber, fibers, and plastics:Many plants, shrubs, and trees exude when cut a white, milk-like liquid which is called latex (from Latin “latex” = fluid). Examples are the rubber plants in our houses and the dandelions in meadows and lawns. Some of these latices coagulate on exposure to air to more or less sticky, elastic masses, but air really has not much to do with it. A rubber latex is an emulsion of microscopically small rubber droplets (diameter ca. 0.0005–0.001 mm) in a dilute aqueous solution of proteins, fats, carbohydrates, salts, etc. The rubber droplets have a lower density then the surrounding water solution. But being “lighter”, they float to the surface similar to the cream in non-pasteurized milk (milk is also an aqueous emulsion, albeit of protein and fat droplets). The rubber droplets then start sticking together and form a film when the water evaporates.