Preparation of hydrophobic HKUST-1 material and study on its water adsorption performance
Feng, Zhihao (2023)
Feng, Zhihao
2023
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Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:amk-202303274236
https://urn.fi/URN:NBN:fi:amk-202303274236
Tiivistelmä
Metal Organic Frameworks have the advantages of porosity, large specific surface area and unsatu-rated metal sites, and are widely used in the fields of adsorption separation, membrane separation and catalysis. However, in practical applications, due to the influence of factors such as water com-petitive adsorption and poor water stability, the adsorption performance of the material is considera-bly reduced. In response to this problem, HKUST-1 materials were quickly prepared under normal temperature and pressure, and then hydrophobically modified it to enhance the hydrophobic proper-ties of the material. Subsequently, the water adsorption performance of the material before and after the hydrophobic modification was measured under different relative humidity conditions by gravi-metric method.
The results show that the BET specific surface area of the hydrophobically modified material has changed from 1016.2 m²/g to 904.7 m²/g, means that it has slightly reduced. However, the hydropho-bic performance has considerably improved. The left contact angle is 125.0°, and the right contact angle is 127.3°. When the relative humidity is 81%, the water adsorption capacity of the original material after hydrophobic modification is reduced from 23.7 mmol/g to 15.1 mmol/g, which is a decrease of 36.3%, and the diffusion coefficient changes from 1.88×10-13 cm2/s to 1.46×10-13cm2/s. At a relative humidity of 32.8%, the material's water adsorption capacity decreased from 19.9 mmol/g to 14.1 mmol/g, which is a decrease of 29.1%, and the diffusion coefficient changed from 1.54×10-13 cm2/s to 1.36×10-13 cm2/s.
The results show that the BET specific surface area of the hydrophobically modified material has changed from 1016.2 m²/g to 904.7 m²/g, means that it has slightly reduced. However, the hydropho-bic performance has considerably improved. The left contact angle is 125.0°, and the right contact angle is 127.3°. When the relative humidity is 81%, the water adsorption capacity of the original material after hydrophobic modification is reduced from 23.7 mmol/g to 15.1 mmol/g, which is a decrease of 36.3%, and the diffusion coefficient changes from 1.88×10-13 cm2/s to 1.46×10-13cm2/s. At a relative humidity of 32.8%, the material's water adsorption capacity decreased from 19.9 mmol/g to 14.1 mmol/g, which is a decrease of 29.1%, and the diffusion coefficient changed from 1.54×10-13 cm2/s to 1.36×10-13 cm2/s.