Frequently Asked Questions


GELEST is an acronym for Germanium, Lead, Silicon and Tin, the Group 14 metals of the Periodic Table. Gelest® is a trademark of Gelest Inc. a manufacturer of metal-organic derivatives of silicon, germanium, tin and lead located in Morrisville, PA. For more information, see the “About Gelest” tab in the navigation bar at the top of the homepage.

Yes, Gelest is dedicated to providing quality specialty silanes, silicones and metal-organic products. Gelest addresses the quality needs by market and by customer.

View the Gelest Quality Policy or Download Current Certificate

Enter the product code, CAS number, or name into the search bar on the homepage. Locate the product in the search results. Click the “SDS” button to the right of the product information. If no “SDS” button exists, contact

Click on the orange magnifying glass in the top right hand corner of the home page and enter your known information into the search bar. Click “Search”. Alternatively, enter search criteria into the “Search by Product”field or draw the chemical structure using the “Search by Structure” feature.

The data that we have for our products can be found in our literature or on the website. To find the data on the website locate the product of interest by using the search function. Open the product page by clicking the “product details” button next to the product code and name in the search results. Technical data can be found below the product details. Contact if you need more information.

Click “Contact” in the menu and select “Technical Questions”. Fill out all of the required information in the form and enter the name or C.A.S. number.


Browse our Product Selection Guide or click the “Product Selection Guide” box on any page.

  1. Select the class of materials
    • Metal-Organics
    • Monomers, Polymer Intermediates, CVD/Pre-Ceramic
    • Organic Synthesis
    • Performance Products
    • Reactive Silicones and Resins
    • Stable, Inert Fluids
    • Surface Modification
  2. Filter using the drop-down menus on the left side

Click on “Search by Structure” on the header of the homepage and draw the structure or sub-structure of interest. Click Search.

In selecting hydrolyzable groups you should consider reactivity, by-products, safety, and your method of treatment. For example, alkoxy functional silanes are an environmentally friendly product because the by-product is alcohol; however, the reactivity is relatively slow. To filter by hydrolyzable group, visit our Selection Guide and select Surface Modification.

Dipodal silanes contain hydrolyzable groups at two positions in the molecule. Functional dipodal silanes and combinations of non-functional dipodal silanes with functional silanes have significant impact on substrate bonding, hydrolytic stability and mechanical strength of many composites systems. To view a list of dipodal silanes, visit our Selection Guide and select “Surface Modification” then filter for “dipodal” in the “Structure” drop-down menu.

Or find out more here.

Hydrolytic stability can be viewed two ways. First, hydrolytic stability of the silanes themselves. The concepts can be directly related to the reactivity, hydrolysis rate and condensation rate. Second, hydrolytic stability of covalently bonded silanes on substrates. Dipodal silanes can improve the stability on substrates.


The thermal stability of silanes is related to the chemical structure. Phenyl modified silanes show relatively good stability. For more information, see the product details of the materials that you are interested in.


Surface Modification

Silanes contain dual functions, an organo reactive group for polymers and hydrolyzable groups for inorganics or metal oxide substrates. Therefore, silanes can provide covalent bonds at the interface between polymers and substrates, ultimately enhancing adhesion. Browse our Selection Guide and select “Surface Modification” or Coupling Agents application page for assistance.

The optimum performance of silanes is associated with siliceous substrates which provide hydrolytically stable oxides; however, the use of silanes has been extended to metal substrates or plastics. Therefore, the effectiveness and strategies for bonding to these less favorable substrates vary.

Silanes can be applied with various methods such as solution treatment or bulk deposition for particulates, or chemical vapor deposition when a monolayer deposition is desirable. For detailed information please see Gelest’s Coupling Agents Brochure or Coupling Agents application pages. For information related to the amount of silane needed for a given surface, visit our Tools and Calculators.

Silane deposition involves with 4 steps:

  1. Hydrolysis
  2. Condensation
  3. Hydrogen bonding
  4. Bond Formation



We recommend a starting ratio of 1 vinyl to 1.5 hydride. To determine the ratio to use for your chosen products, visit our calculator and choose the products that you are interested in from the drop-down menus.

Tools & Calculators

Personal Care

SiBrid® is a trademark of Gelest Inc. designated for materials that are hybrids of silicone and organic materials. SiBrid® fluids are hybrid organic-inorganic fluids used in cosmetic and personal care applications.


Visit our Product Selection Guide, select “Metal-Organics” and use the “Metal Center” or “Application” filters on the left to select relevant criteria.

Have Questions? Call 888.734.8344


Copyright 1991 - 2019 Gelest, Inc.