Three-Dimensional Cage Type Mesoporous CN-Based Hybrid Material with Very High Surface Area and Pore Volume

2007 ◽  
Vol 19 (17) ◽  
pp. 4367-4372 ◽  
Author(s):  
Ajayan Vinu ◽  
Pavuluri Srinivasu ◽  
Dhanashri P. Sawant ◽  
Toshiyuki Mori ◽  
Katsuhiko Ariga ◽  
...  
Author(s):  
Ketki Lichade ◽  
Yizhou Jiang ◽  
Yayue Pan

Abstract Recently, many studies have investigated additive manufacturing of hierarchical surfaces with high surface area/volume (SA/V) ratios, and their performance has been characterized for applications in next-generation functional devices. Despite recent advances, it remains challenging to design and manufacture high SA/V ratio structures with desired functionalities. In this study, we established the complex correlations among the SA/V ratio, surface structure geometry, functionality, and manufacturability in the Two-Photon Polymerization (TPP) process. Inspired by numerous natural structures, we proposed a 3-level hierarchical structure design along with the mathematical modeling of the SA/V ratio. Geometric and manufacturing constraints were modeled to create well-defined three-dimensional hierarchically structured surfaces with a high accuracy. A process flowchart was developed to design the proposed surface structures to achieve the target functionality, SA/V ratio, and geometric accuracy. Surfaces with varied SA/V ratios and hierarchy levels were designed and printed. The wettability and antireflection properties of the fabricated surfaces were characterized. It was observed that the wetting and antireflection properties of the 3-level design could be easily tailored by adjusting the design parameter settings and hierarchy levels. Furthermore, the proposed surface structure could change a naturally-hydrophilic surface to near-superhydrophobic. Geometrical light trapping effects were enabled and the antireflection property could be significantly enhanced (>80% less reflection) by the proposed hierarchical surface structures. Experimental results implied the great potential of the proposed surface structures for various applications such as microfluidics, optics, energy, and interfaces.


2016 ◽  
Vol 75 (2) ◽  
pp. 350-357
Author(s):  
Graham Dawson ◽  
Wei Chen ◽  
Luhua Lu ◽  
Kai Dai

The adsorption properties of two nanomorphologies of trititanate, nanotubes (TiNT) and plates (TiNP), prepared by the hydrothermal reaction of concentrated NaOH with different phases of TiO2, were examined. It was found that the capacity for both morphologies towards methylene blue (MB), an ideal pollutant, was extremely high, with the TiNP having a capacity of 130 mg/g, higher than the TiNT, whose capacity was 120 mg/g at 10 mg/L MB concentration. At capacity, the well-dispersed powders deposit on the floor of the reaction vessel. The two morphologies had very different structural and adsorption properties. TiNT with high surface area and pore volume exhibited exothermic monolayer adsorption of MB. TiNP with low surface area and pore volume yielded a higher adsorption capacity through endothermic multilayer adsorption governed by pore diffusion. TiNP exhibited a higher negative surface charge of −23 mV, compared to −12 mV for TiNT. The adsorption process appears to be an electrostatic interaction, with the cationic dye attracted more strongly to the nanoplates, resulting in a higher adsorption capacity and different adsorption modes. We believe this simple, low cost production of high capacity nanostructured adsorbent material has potential uses in wastewater treatment.


2017 ◽  
Vol 1 (6) ◽  
pp. 1414-1424 ◽  
Author(s):  
Michael Cox ◽  
Robert Mokaya

Mesoporous carbons (with up to 95% of pore volume from mesopores) with surface area and pore volume of ∼4000 m2 g−1 and ∼3.6 cm3 g−1, respectively, are excellent CO2 absorbers under pre combustion conditions and can store 55 mmol g−1 (i.e., 2.42 g g−1) or 930 g l−1 at 25 °C and 50 bar.


2003 ◽  
Vol 788 ◽  
Author(s):  
A. Akash ◽  
B. Nair ◽  
K. Minnick ◽  
M. Wilson ◽  
J. Hartvigsen

ABSTRACTA novel nano-ceramic material, called HSA-CERCANAM®, which has a very high surface area with a nanopore network has been developed. HSA-CERCANAM® can be casted in various shapes and forms resulting in a monolithic piece that has surface area as high as 80–100 m2/g. The surface area and the nanopore network of HSA-CERCANAM® remains stable at temperatures as high as 1000°C. Furthermore, the unique nature of HSA-CERCANAM® allows it to be casted on and around features, either sacrificial or permanent. Using sacrificial features, microchannels can be incorporated internally into the monolithic HSA-CERCANAM® piece in a simple, one-step process. Further, this monolithic ceramic component, which has an intrinsically high surface area and a nanopore network, can be infiltrated with a desired catalyst. This could offer clear technological advantages over currently available microreactors. The surface area, porosity, catalyst type and infiltration levels are some of the ways in which tailored microstructures can be realized in components such as mixers, heat exchangers, extractors, filters or reaction chambers thereby leading to highly efficient, multi-functional ceramic micro-devices.


2016 ◽  
Vol 23 (5) ◽  
pp. 1227-1237 ◽  
Author(s):  
Haribandhu Chaudhuri ◽  
Subhajit Dash ◽  
Ashis Sarkar

2016 ◽  
Vol 35 (6) ◽  
pp. 535-541 ◽  
Author(s):  
Hongying Xia ◽  
Jian Wu ◽  
Chandrasekar Srinivasakannan ◽  
Jinhui Peng ◽  
Libo Zhang

AbstractThe present work attempts to convert bamboo into a high surface area activated carbon via microwave heating. Different chemical activating agents such as KOH, NaOH, K2CO3 and Na2CO3 were utilized to identify a most suitable activating agent. Among the activating agents tested KOH was found to generate carbon with the highest porosity and surface area. The effect of KOH/C ratio on the porous nature of the activated carbon has been assessed. An optimal KOH/C ratio of 4 was identified, beyond which the surface area as well as the pore volume were found to decrease. At the optimized KOH/C ratio the surface area and the pore volume were estimated to be 3,441 m2/g and 2.093 ml/g, respectively, with the significant proportion of which being microporous (62.3%). Activated carbon prepared under the optimum conditions was further characterized using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM). Activated carbons with so high surface area and pore volume are very rarely reported, which could be owed to the nature of the precursor and the optimal conditions of mixture ratio adopted in the present work.


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