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Quick high-temperature hydrothermal synthesis of mesoporous materials with 3D cubic structure for the adsorption of lysozyme

View Article: PubMed Central - PubMed

ABSTRACT

Three-dimensional cage-like mesoporous FDU-12 materials with large tuneable pore sizes ranging from 9.9 to 15.6 nm were prepared by varying the synthesis temperature from 100 to 200 °C for the aging time of just 2 h using a tri-block copolymer F-127(EO106PO70EO106) as the surfactant and 1,3,5-trimethyl benzene as the swelling agent in an acidic condition. The mesoporous structure and textural features of FDU-12-HX (where H denotes the hydrothermal method and X denotes the synthesis temperature) samples were elucidated and probed using x-ray diffraction, N2 adsorption, 29Si magic angle spinning nuclear magnetic resonance, scanning electron microscopy and transmission electron microscopy. It has been demonstrated that the aging time can be significantly reduced from 72 to 2 h without affecting the structural order of the FDU-12 materials with a simple adjustment of the synthesis temperature from 100 to 200 °C. Among the materials prepared, the samples prepared at 200 °C had the highest pore volume and the largest pore diameter. Lysozyme adsorption experiments were conducted over FDU-12 samples prepared at different temperatures in order to understand their biomolecule adsorption capacity, where the FDU-12-HX samples displayed high adsorption performance of 29 μmol g−1 in spite of shortening the actual synthesis time from 72 to 2 h. Further, the influence of surface area, pore volume and pore diameter on the adsorption capacity of FDU-12-HX samples has been investigated and results are discussed in correlation with the textural parameters of the FDU-12-HX and other mesoporous adsorbents including SBA-15, MCM-41, KIT-5, KIT-6 and CMK-3.

No MeSH data available.


Nitrogen adsorption–desorption isotherms of (A) FDU-12-H200 with different aging durations. (●) 1 h (■) 2 h, and (▼) 4 h and (B) FDU-12-H at different temperatures with an aging duration of 2 h. (●) 100 °C (■) 130 °C (▼) 150 °C (▲) 180 °C and (♦) 200 °C. STP stands for standard temperature and pressure.
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Figure 2: Nitrogen adsorption–desorption isotherms of (A) FDU-12-H200 with different aging durations. (●) 1 h (■) 2 h, and (▼) 4 h and (B) FDU-12-H at different temperatures with an aging duration of 2 h. (●) 100 °C (■) 130 °C (▼) 150 °C (▲) 180 °C and (♦) 200 °C. STP stands for standard temperature and pressure.

Mentions: The effect of the synthesis time on the textural parameters of FDU-12-HX was assessed by nitrogen adsorption–desorption measurements. Figure 2(A) shows the N2 adsorption–desorption isotherms of FDU-12 synthesized at 200 °C for different synthesis times. The isotherms of all the calcined samples are of type IV isotherm with a pronounced capillary condensation step at a higher relative pressure, revealing the presence of large pore systems. However, the broadness of the hysteresis loop is decreased with increasing synthesis time. The type of hysteresis loop also changes from H2 to H1 upon increasing the synthesis time from 1 to 4 h. These results reveal that the shorter synthesis time favours the cage type pores as it gives a H2 type hysteresis loop whereas enlarged large cage type pores with narrow pore size are obtained when the synthesis time was increased above 1 h. It should also be noted that the total amount of nitrogen adsorbed for the samples prepared with the aging time of 2 h is higher as compared to that of other samples, indicating that the reaction time of 2 h is the best condition to obtain samples with a large pore volume. When the syntheses were performed at a high temperature with the aging time of 1 and 4 h, samples with lower pore volume were obtained. It is also interesting to note that the BET surface area decreased from 677.3 to 290.4 m2 g−1 with increasing aging time from 1 to 4 h, whereas the pore volume and pore diameters exhibited a maximum capacity, such as 0.93 cm3 g−1 and 15.6 nm, for the sample with an aging period of 2 h (table 2). It can be seen from the pore size distribution (figure 3(A)) that the peaks are sharper for the sample prepared with the shorter duration, showing better structural order of the mesoporous network. From the nitrogen adsorption and XRD results, it can be concluded that the aging time of 2 h at a temperature of 200 °C is the best condition to obtain a highly ordered FDU-12 sample with larger pore volume and ordered pores.


Quick high-temperature hydrothermal synthesis of mesoporous materials with 3D cubic structure for the adsorption of lysozyme
Nitrogen adsorption–desorption isotherms of (A) FDU-12-H200 with different aging durations. (●) 1 h (■) 2 h, and (▼) 4 h and (B) FDU-12-H at different temperatures with an aging duration of 2 h. (●) 100 °C (■) 130 °C (▼) 150 °C (▲) 180 °C and (♦) 200 °C. STP stands for standard temperature and pressure.
© Copyright Policy - open-access
Related In: Results  -  Collection

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Figure 2: Nitrogen adsorption–desorption isotherms of (A) FDU-12-H200 with different aging durations. (●) 1 h (■) 2 h, and (▼) 4 h and (B) FDU-12-H at different temperatures with an aging duration of 2 h. (●) 100 °C (■) 130 °C (▼) 150 °C (▲) 180 °C and (♦) 200 °C. STP stands for standard temperature and pressure.
Mentions: The effect of the synthesis time on the textural parameters of FDU-12-HX was assessed by nitrogen adsorption–desorption measurements. Figure 2(A) shows the N2 adsorption–desorption isotherms of FDU-12 synthesized at 200 °C for different synthesis times. The isotherms of all the calcined samples are of type IV isotherm with a pronounced capillary condensation step at a higher relative pressure, revealing the presence of large pore systems. However, the broadness of the hysteresis loop is decreased with increasing synthesis time. The type of hysteresis loop also changes from H2 to H1 upon increasing the synthesis time from 1 to 4 h. These results reveal that the shorter synthesis time favours the cage type pores as it gives a H2 type hysteresis loop whereas enlarged large cage type pores with narrow pore size are obtained when the synthesis time was increased above 1 h. It should also be noted that the total amount of nitrogen adsorbed for the samples prepared with the aging time of 2 h is higher as compared to that of other samples, indicating that the reaction time of 2 h is the best condition to obtain samples with a large pore volume. When the syntheses were performed at a high temperature with the aging time of 1 and 4 h, samples with lower pore volume were obtained. It is also interesting to note that the BET surface area decreased from 677.3 to 290.4 m2 g−1 with increasing aging time from 1 to 4 h, whereas the pore volume and pore diameters exhibited a maximum capacity, such as 0.93 cm3 g−1 and 15.6 nm, for the sample with an aging period of 2 h (table 2). It can be seen from the pore size distribution (figure 3(A)) that the peaks are sharper for the sample prepared with the shorter duration, showing better structural order of the mesoporous network. From the nitrogen adsorption and XRD results, it can be concluded that the aging time of 2 h at a temperature of 200 °C is the best condition to obtain a highly ordered FDU-12 sample with larger pore volume and ordered pores.

View Article: PubMed Central - PubMed

ABSTRACT

Three-dimensional cage-like mesoporous FDU-12 materials with large tuneable pore sizes ranging from 9.9 to 15.6 nm were prepared by varying the synthesis temperature from 100 to 200 °C for the aging time of just 2 h using a tri-block copolymer F-127(EO106PO70EO106) as the surfactant and 1,3,5-trimethyl benzene as the swelling agent in an acidic condition. The mesoporous structure and textural features of FDU-12-HX (where H denotes the hydrothermal method and X denotes the synthesis temperature) samples were elucidated and probed using x-ray diffraction, N2 adsorption, 29Si magic angle spinning nuclear magnetic resonance, scanning electron microscopy and transmission electron microscopy. It has been demonstrated that the aging time can be significantly reduced from 72 to 2 h without affecting the structural order of the FDU-12 materials with a simple adjustment of the synthesis temperature from 100 to 200 °C. Among the materials prepared, the samples prepared at 200 °C had the highest pore volume and the largest pore diameter. Lysozyme adsorption experiments were conducted over FDU-12 samples prepared at different temperatures in order to understand their biomolecule adsorption capacity, where the FDU-12-HX samples displayed high adsorption performance of 29 μmol g−1 in spite of shortening the actual synthesis time from 72 to 2 h. Further, the influence of surface area, pore volume and pore diameter on the adsorption capacity of FDU-12-HX samples has been investigated and results are discussed in correlation with the textural parameters of the FDU-12-HX and other mesoporous adsorbents including SBA-15, MCM-41, KIT-5, KIT-6 and CMK-3.

No MeSH data available.