How Envicoat® Works
Envicoat® is a blend of synthetic polymers that is designed to alter the properties of glass and similar nonporous surfaces in such a way as to cause water, sleet and snow to be repelled from the surface. In addition, Envicoat® is also capable of reducing the adhesion and buildup on glass and non-porous surfaces (hereafter referred to simply as glass surfaces) of many other materials such as dust, salt and other forms of environmental substances.
The reason why water and such substances adhere to glass surfaces is the molecules that make up these materials have similar polarities. That is, these substances have dipole moments within their molecular structure that causes the molecule to have a positive and negative end. This property will cause the negative end of one molecule to be attracted to a positive end of another molecule. When a surface has such polar properties it is referred to as being "hydrophilic." This refers to the fact that the surface will attract water molecules and other substances that have polarity properties similar to water. Glass surfaces exhibit hydrophilic properties. Therefore, in order to cause a glass surface to repel water, its polar "hydrophilic" characteristics must be changed in such a way that it becomes nonpolar. A nonpolar surface is referred to as exhibiting "hydrophobic" properties; that is, it repels water.
When Envicoat® is applied to a glass surface it causes the surface to become hydrophobic. The way that this is accomplished is through the use of silicon polymers. Silicones, or more specifically organopolysiloxanes, are polymeric materials that contain silicon, oxygen, and organic groups. The term "polymeric" with respect to these molecules refers to their property of being able to be linked together to form long chain of molecules called polymers. The methyl silicones (also called dimethylpolysiloxanes) are perhaps the most important members of this class of materials. A typical structure of methyl silicon is the polymer shown below:
The value of [X] determines the length of the polymer and thus the molecular weight of the polymer. The molecular weight of the polymer controls many properties of the polymer such as its viscosity, melting point, boiling point, electrical resistivity, etc. The length of the polymer also affects its ability to be used in glass treatment applications. For example if the polymer chain is too short it will not bond to the glass surface very strongly and if the chain length is too long then the polymer will cause a smearing effect to appear on the glass surface. Envicoat® uses silicon polymers of optimum chain length to produce strong bonds to the glass surface without producing a smearing effect. In addition, Envicoat contains a special catalyst that helps to promote rapid bonding of the silicon polymers to the glass surface.
When the silicon polymers are bound to the glass surface, the surface changes from hydrophilic to hydrophobic. This change occurs because there are now the methyl groups (-CH3 ) that stick out from the glass surface. This is important because the (-CH3) group is nonpolar. Thus, when a water molecule approaches the silicon-treated surface it sees no attractive sites to bond to and thus will seek out other water molecules to bond to instead of bonding to the glass surface. This causes the water molecules to form small droplets (i.e. beads) on the glass surface. Since these beads of water are not attracted to the glass surface they are easily removed via such forces as wind currents or other physical forces. A similar shedding process also occurs for other polar materials such as dust, etc. Thus, Envicoat® functions as a very effective method for minimizing maintenance time and expense in keeping glass surfaces clean.