TY - JOUR
T1 - Enhanced mechanical stability and scratch resistance of mesoporous aluminosilicate thin films
AU - Reid, Barry
AU - Mane, Ishaa
AU - Ahmed, Faizah
AU - Jara Fornerod, Maximiliano
AU - Füredi, Máté
AU - Schmidt-Hansberg, Benjamin
AU - Alvarez-Fernandez, Alberto
AU - Guldin, Stefan
N1 - Funding Information:
The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Guldin reports financial support was provided by Engineering and Physical Sciences Research Council . Guldin reports financial support was provided by BASF SE.
Funding Information:
A.A.F., M.J.F., and S.G. acknowledge funding by the EPSRC New Investigator Award ( EP/R035105/1 ). B.R. was supported by an EPSRC Industrial Case Award ( EP/M506448/1 ) in support of BASF . M.J.F acknowledge the support of the Henry Royce Institute through the Royce PhD Equipment Access Scheme enabling access to microscopy facilities at Royce@Cambridge; EPSRC Grant Number EP/R00661X/1 .
Funding Information:
EP provides a reliable method for the determination of total porosity in mesoporous thin films [73,79]. Contrary to more commonly used techniques to study surface morphology (like scanning electron or atomic force microscopy), EP probes the accessible porosity across the entire film thickness and for a representative sample volume [71,72,80]. Moreover, EP provides also information about pore size distribution and the Youngs modulus [ 77,81]. As shown in the Supporting Information (Fig. S3), some changes were also observed with the modification over the O:I ratio: 7.2 ± 0.1 nm (AlSi-20); 8.2 ± 0.3 nm (AlSi-30) and 10.0 ± 0.1 nm (AlSi-40), which is in agreement with previous studies [69], Young's modulus (E) values were obtained from the fitting of the EP measurements (Fig. 2D). A clear decrease in Young's modulus was found with increasing porosity from the EP measurements (Fig. 2E) or in return, the lower the porosity, the stiffer the films. Samples with high inorganic content, and therefore low porosity (AlSi-20) displayed an E of 3.4 ± 0.3 GPa. This value was significantly reduced to 1.3 ± 0.2 GPa for samples with higher porosity (AlSi-30) and reached its minimum value for the highest porous films (AlSi-40) with 0.6 ± 0.1 GPa.The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Guldin reports financial support was provided by Engineering and Physical Sciences Research Council. Guldin reports financial support was provided by BASF SE.A.A.F. M.J.F. and S.G. acknowledge funding by the EPSRC New Investigator Award (EP/R035105/1). B.R. was supported by an EPSRC Industrial Case Award (EP/M506448/1) in support of BASF. M.J.F acknowledge the support of the Henry Royce Institute through the Royce PhD Equipment Access Scheme enabling access to microscopy facilities at Royce@Cambridge; EPSRC Grant Number EP/R00661X/1.
Publisher Copyright:
© 2022 The Authors
PY - 2022/11
Y1 - 2022/11
N2 - Mesoporous coatings are widely used in industries such as optics, display technologies, photovoltaics, and bioengineering, due to their attractive properties such as high surface area to volume ratio and excellent mass and electron transport characteristics. While structural parameters and material composition can be routinely tailored to the respective applications, improvements in their mechanical properties and robustness, essential for their long-term performance, remain a challenge. Herein, we provide a comprehensive study on the relationship between the degree of porosity, type of material processing and resulting mechanical properties for the use case of mesoporous aluminosilicate thin films that were co-assembled via a sacrificial block copolymer structure-directing agent. Several routes, including the introduction of chelating agents on the precursor solution, a two-step calcination process, and a variation over the aluminium content were explored with the objective of improving the scratch resistance and mechanical properties of the final mesoporous thin film. Pencil hardness tests were combined with atomic force microscopy analysis to investigate the macroscopic scratch resistance, i.e. plastic deformation. Ellipsometric porosimetry served to determine the elastic deformation of the nanoscopic architecture via measurement of the Young's modulus. Our comparative investigation highlights the promising role of organic chelating agents in the sol-gel formulation to slow down the hydrolysis of the aluminium precursor, which facilitated improvements in the mechanical performance close to industrial standard.
AB - Mesoporous coatings are widely used in industries such as optics, display technologies, photovoltaics, and bioengineering, due to their attractive properties such as high surface area to volume ratio and excellent mass and electron transport characteristics. While structural parameters and material composition can be routinely tailored to the respective applications, improvements in their mechanical properties and robustness, essential for their long-term performance, remain a challenge. Herein, we provide a comprehensive study on the relationship between the degree of porosity, type of material processing and resulting mechanical properties for the use case of mesoporous aluminosilicate thin films that were co-assembled via a sacrificial block copolymer structure-directing agent. Several routes, including the introduction of chelating agents on the precursor solution, a two-step calcination process, and a variation over the aluminium content were explored with the objective of improving the scratch resistance and mechanical properties of the final mesoporous thin film. Pencil hardness tests were combined with atomic force microscopy analysis to investigate the macroscopic scratch resistance, i.e. plastic deformation. Ellipsometric porosimetry served to determine the elastic deformation of the nanoscopic architecture via measurement of the Young's modulus. Our comparative investigation highlights the promising role of organic chelating agents in the sol-gel formulation to slow down the hydrolysis of the aluminium precursor, which facilitated improvements in the mechanical performance close to industrial standard.
KW - Block copolymers
KW - Co-assembly
KW - Mechanical properties
KW - Mesoporous
KW - Scratching
KW - Thin-film
UR - http://www.scopus.com/inward/record.url?scp=85139360556&partnerID=8YFLogxK
U2 - 10.1016/j.micromeso.2022.112246
DO - 10.1016/j.micromeso.2022.112246
M3 - Article
AN - SCOPUS:85139360556
SN - 1387-1811
VL - 345
JO - Microporous and Mesoporous Materials
JF - Microporous and Mesoporous Materials
M1 - 112246
ER -