Silicon Nitride membranes have been modified using Atomic Layer-Deposited (ALD) techniques to change their surface properties. Depending on the process used, both Hydrophilic and Hydrophobic substrates have been created with the following advantages:
Choice between low and high surface energies
Smooth and conformal substrates
Enhanced wetting and biocompatibility (hydrophilic)
No need for plasma treatment of surface prior to cell growth
Hydrophobic coating offers novel platform for deposition and growth of nanomaterials
Hydrophobic surfaces improve sample preparation for materials that are dissolved or suspended in organics solvents. Nanoparticles in organic solvents (such as carbon nanotubes) will readily disperse on the Silicon Nitride membrane surface.
Hydrophilic surfaces enhance wetting and dispersion of aqueous solutions. This avoids particle aggregation effects commonly observed on less hydrophilic surfaces. Particularly useful in water based sols and life science applications.
Both coatings are available on 50nm and 200nm PELCO® Silicon Nitride Membranes with a 0.5 x 0.5mm window and 15nm Silicon Nitride membrane with 9 each 0.1 x 0.1mm windows on a 200µm silicon frame with a diameter of 3mm, compatible with all standard TEM grid holders. Both sides of the membrane and frame are coated. We advise to handle the discs by gripping at the edge.
Specifications:
Hydrophilic: 2.5nm atomic layer-deposited hydroxylated alumina on 15, 50 and 200nm ultra-low-stress silicon nitride membrane
Hydrophobic: 2.5nm atomic layer-deposited alumina and fluoro-methyl-silane on 15, 50 and 200nm ultra-low-stress silicon nitride membrane
Surface Energy:
Surface
Surface Energy (mJ/m2)
Standard Deviation
Silicon Nitride Membrane
46.1
4.3
Hydrophilic Coating
76.1
2.2
Hydrophobic Coating
24.6
4.4
mj= millijoules
Surface Roughness:
Surface
Surface Roughness (nm)
Standard Deviation
Silicon Nitride Membrane
Rq=0.65 Ra=0.45
0.06 0.02
Hydrophilic Coating
Rq=0.57 Ra=0.40
0.04 0.03
Hydrophobic Coating
Rq=0.66 Ra=0.40
0.03 0.05
Rq= Surface Roughness; Ra= Roughness Average
Film Thickness: Resilient, low stress 15, 50 and 200nm, giving rise to minimum absorption to enable clear imaging
Window Sizes: Array of 9 ea. 0.1 x 0.1mm and 0.5 x 0.5mm
Frame Thickness: Silicon support structure is 200µm standard.
Frame Diameter: EM standard 3mm diameter disc, fully compatible with standard TEM holders (no broken edges)
EasyGrip™Edgesfor easy handling with tweezers
Packaging: The PELCO®Silicon Nitride Support Films are packaged under cleanroom conditions. Each box holds 10 support films