User:Lilyfels/Silanization

Goals: Expand Properties and Mechanism sections of Silanization page. Sources need to be found for added information, an image may be helpful in the mechanism section if a good one is found.

Memo: I chose this article since I have performed silanization reactions while on co-op. The chemistry and properties of these reactions are extremely interesting and have wide applications. When I was researching the process for work, I came across the wikipedia article and was surprised at how little information it provided. Wikipedia should accept these revisions because they provide more detail on silanization, which is a well-used procedure in surface modification. These edits are important so that someone who is looking at a possible silanization procedure can easily see if it will provide the desired properties and be a feasible reaction. The sources are textbook chapters or published papers in peer-reviewed articles, so I believe them to be credible and of good quality. Since these edits provide facts on the silanization method, it is from a neutral point of view. It is difficult to create a biased article based on a reaction.

[This is just a rough outline of points I want to add, exact wording will be adjusted later, citations will be added in correct places once wording is complete]

Properties:

-Surface usually becomes hydrophobic, can be modified based on side chains of silane compound used. Most have alkyl groups. Regular substrates have -OH groups on surface which reacts with silane compound, silane side chains are non-polar compared to -OH groups creating hydrophobic surface. Once the surface has been functionalized, further reaction can be performed to graft molecules with various properties onto the substrate such as hydrophilicity, hydrophobicity, self cleaning, photocatalytic, and more. Aside from clear applications in coatings and material science, silanization is also used in biomedical fields to anchor DNA to substrates.

Sources:

https://onlinelibrary.wiley.com/doi/full/10.1002/admi.201902134

https://www.sciencedirect.com/science/article/pii/S0927775711007370?casa_token=qijlJVKewXYAAAAA:Jg8dquKe_SbzzguWRheb68Unf9kDuk2d3kN81EW_3Nq4x6wjXRyWAi5pKNiAlPQN-7uGYbvgfLI#fig0005

https://www.future-science.com/doi/10.2144/000113002

Due to the hydrophobic nature of silanized substrates, glass containers for sticky substances are often silanized to prevent sticking.

Source: https://currentprotocols.onlinelibrary.wiley.com/doi/epdf/10.1002/0471142735.ima03ks21?saml_referrer

Mechanism:

Silanization begins with activated substrate to expose surface hydroxyl groups. The substrate is soaked in a solution containing the desired silane compound. Often, chlorosilanes are used due to their extreme reactivity. The silane can then be linked to the oxygen, creating a stable Si-O bond. This reaction occurs spontaneously and no catalyst is needed.

Sources:

https://pubs.acs.org/doi/10.1021/j100727a046

2nd Draft:

Properties

Silanized surfaces are usually hydrophobic, but the surface properties can be adjusted by varying the side chains of the silane compound. Many common silane compounds have alkyl groups which are more nonpolar than the hydroxyl groups on the untreated surface, creating a hydrophobic surface. Once the surface has been functionalized, further reactions can be performed to graft molecules with properties such as hydrophilicity, hydrophobicity, self cleaning, photocatalytic, and more onto the substrate. Aside from clear applications in coatings and material science, the silanization process is also used in biomedical fields to anchor DNA to substrates. Applications in coatings include silanizing glass containers that hold sticky substances to prevent sticking.

Mechanism

Silanization begins with activating the desired substrate to expose surface hydroxyl groups. The activated substrate is then placed in a silane solution to react; often, chlorosilanes are used due to their extreme reactivity. The silane is linked to the oxygen in the hydroxyl group, producing hydrochloric acid and a stable Si-O bond. This reaction occurs spontaneously and no catalyst is needed.

Final Draft:

Properties

Silanized surfaces are usually hydrophobic, but the surface properties can be adjusted by varying the side chains of the silane compound. Many common silane compounds have alkyl groups (containing only carbon and hydrogen) which are more nonpolar than the hydroxyl (-OH) groups on the untreated surface, creating a hydrophobic surface. Once the surface has been functionalized, further reactions can be performed to graft molecules with properties such as hydrophilicity, hydrophobicity, self cleaning, photocatalytic, and more onto the substrate. Aside from clear applications in coatings and material science, the silanization process is also used in biomedical fields to anchor DNA to substrates. Applications in coatings include silanizing glass containers that hold sticky substances to prevent sticking.

Mechanism

Silanization begins with activating the desired material to expose surface hydroxyl (-OH) groups. The activated substrate, or material, is then placed in a silane solution to react; often, chlorosilanes are used due to their extreme reactivity. The silane is linked to the oxygen in the hydroxyl group, producing hydrochloric acid and a stable Si-O bond. This reaction occurs spontaneously and no catalyst is needed.