Mechanical properties of ordered mesoporous oxides thin films

Mesoporous ordered films via self-assembly: trends and perspectives

“…For a detailed review of the subject, see Soler-Illia and coworkers' work. 59 In general, it has been found, as expected, a direct relationship between porosity and E and H. However, the mechanical properties of thin films deposited by the liquid phase, such as sol–gel and mesoporous films, are highly dependent on the stress generated during heat treatment, which induces shrinkage in the direction perpendicular to the substrate. Such stress can induce fractures and delamination.…”

“…Various techniques have been employed, such as surface acoustic waves 55 , nanoindentation 56 , ellipsometric porosimetry 57 and X-ray reflectivity 58 to evaluate the mechanical properties in mesoporous films. For a detailed review of the subject, see Soler-Illia and coworkers' work 59 . In general, it has been found, as expected, a direct relationship between porosity and E and H. However, the mechanical properties of thin films deposited by the liquid phase, such as sol-gel and mesoporous films, are highly dependent on the stress generated during heat treatment, which induces shrinkage in the direction perpendicular to the substrate.…”

Enhanced Mechanical Stability and Scratch Resistance of Mesoporous Aluminosilicate Thin Films

“…However, the induced porosity results in unfavourable mechanical properties of the coatings, reducing their structural integrity and scratch resistance and compromising their long-term performance. [20] Numerous strategies have been reported to improve the mechanical characteristics of mesoporous films by either modifying the formulation of the precursor solution or via post-coating film treatment. [20] Precoating modifications include the addition of reflux and sol additives such as tetrapropylammonium hydroxide to the inorganic solution, promoting the condensation reaction between silanols groups, and improving the mechanical strength of the final mesoporous films while keeping high porosity values.…”

“…[20] Numerous strategies have been reported to improve the mechanical characteristics of mesoporous films by either modifying the formulation of the precursor solution or via post-coating film treatment. [20] Precoating modifications include the addition of reflux and sol additives such as tetrapropylammonium hydroxide to the inorganic solution, promoting the condensation reaction between silanols groups, and improving the mechanical strength of the final mesoporous films while keeping high porosity values. [21] Alternatively, the addition of harder metallic elements such as organofunctional metal alkoxides or metallic nanoparticles has shown the possibility of modifying the hardness of the final mesoporous materials, achieving values as high as 5H pencil hardness.…”

Enhanced Mechanical Stability and Scratch Resistance of Mesoporous Aluminosilicate Thin Films

“…Typically, the use of a sacrificial organic porogen or structure-directing agent provides access to control over the porosity of the resulting mesoporous inorganic coating. However, the induced porosity results in unfavourable mechanical properties of the coatings, reducing their structural integrity and scratch resistance and compromising their long-term performance [20].…”