Tailoring Pore Size and Surface Properties of High-Strength Microporous Nickel Inverse Opals for Fast and Efficient Immunomagnetic Separation of Exosomes

2021 ◽  
Author(s):  
Zhimin Jiang ◽  
Andrew Lin ◽  
David Issadore ◽  
James Pikul
2010 ◽  
Vol 150-151 ◽  
pp. 1754-1757 ◽  
Author(s):  
Peng Liu ◽  
Zhi Wu Yu ◽  
Ling Kun Chen ◽  
Zhu Ding

The influence of curing time on the mechanical property of the phosphoaluminate cement (PAC) was investigated, and the mechanism was discussed as well. The phase composition and morphology of hydration products, electrical properties, porosity and pore size distribution of PAC cured different age were analyzed with XRD, EIS and MIP. The results showed PAC has the property of early-high strength, and the compressive strength of PAC cured for 1 day was about 70% of 28 days’. The main hydration products of PAC are micro-crystal phase and gel of phosphate and phosphoaluminate which formed compacter microstructure. In addition, there are no calcium hydroxide (CH) and ettringite (AFt) produced during the process of hydration. The compressive strength of PAC increased with age, which was due to more products continuously produced. The ac resistance analysis manifested as the change of the nyquist pattern and resistance value.


2012 ◽  
Vol 518-523 ◽  
pp. 352-355
Author(s):  
Hui Liu ◽  
Hong Liang Li ◽  
Meng Xue Wang ◽  
Jing Jing Sang ◽  
Xiu Song Zhao

Methylene blue (MB) was used as model molecule to investigate the effects of surface properties and solvent pH values on the adsorption and desorption (or release) behaviors of mesoporous SBA-15 materials. It was found that the treatment of SBA-15 with a pH 7.8 aqueous solution can enhance the adsorption rate and capacity in comparison with the pristine SBA-15. The effect of pH values on MB releasing from the weak base treated SBA-15 and the pristine one have been studied and been compared in pH values range from 0.5 to 7.0. Both of them showed a maximum releasing rate at about pH 2 and all of the treated SBA-15 samples showed a higher releasing quantity than the pristine ones. The influence mechanisms of base treatment on the adsorption ability and that of pH values on the releasing properties of SBA-15 samples have been analyzed and been discussed based on the composition, the morphology, the surface area and pore size distribution and adsorption/desorption measurements.


2011 ◽  
Vol 194-196 ◽  
pp. 2135-2139
Author(s):  
Yi Neng Fang ◽  
Hua Zhi Gu ◽  
Yun Sheng Fen ◽  
Lin Jun Wang ◽  
Yan Jing Li

High-strength and micropore lightweight bauxite aggregate was fabricated by low grade raw bauxite powder, aluminium hydroxide powder and organic polymer (OP). OP was used as consolidator, binder and pore former and aluminium hydroxide was used as pore former. The influence of OP and aluminium hydroxide content on the property of the samples was studied. The phase composition and the microstructure of the sintered samples were characterized by XRD, SEM and the pore size distribution was measured by mercury porosimety. The results demonstrate that the bulk density of the samples decreases linearly and the apparent porosity of the samples increases gradually with the addition of OP. The lowest density reached 1.13g/cm3when adding 35% OP and 10% Al(OH)3. The average pore size is around 5μm, and increases with the addition of OP increased. The XRD showed the main phase of the sample is mullite and some little amount of corundum.


1991 ◽  
Vol 251 ◽  
Author(s):  
Atsushi Takata ◽  
K. Ishizaki ◽  
Y. Kondo ◽  
T. Shioura

ABSTRACTOpen porous copper metals, which have high strength, high open porosity and well controlled pore size distribution, were produced by a hot isostatic press (HIP) process. They were sintered at different temperatures from 973 to 1273K under various HIPping pressures up to 200MPa. Pore size distribution and Young's modulus of the sintered samples were analyzed. The HIPped products have greater strength and higher open porosity than those of the normally sintered ones. The internal structural parameters such as pore size distribution were controlled by changing the HIPping pressure.


1996 ◽  
Vol 118 (4) ◽  
pp. 856-862 ◽  
Author(s):  
A. D. Peralta ◽  
D. C. Wu ◽  
P. J. Brehm ◽  
J. C. Cuccio ◽  
M. N. Menon

The capability to perform accurate fast-fracture strength predictions for ceramic components under complex stress states must be available in order to transition the use of advanced, high-strength ceramic materials from the laboratory to the high-strength/high-temperature applications they are intended for. Multiaxial strength prediction theories have provided the prediction capabilities, but only limited testing of these theories under complex states of stress and stress gradient conditions has been performed previously. Presented here are comprehensive test results and strength predictions for ceramic components subjected to complex states of stress and stress gradient conditions. The results show excellent agreement of the predictions from the multiaxial theories with test results for volumetrically distributed flaws. An important finding of this work is the problem that arises in performing component surface strength predictions from database-type specimens. Database-type specimens and component surface properties are not necessary correlated, and in many cases it may be completely inaccurate to use database-type specimen surface properties for component surface strength predictions.


Metals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 244 ◽  
Author(s):  
Nakarin Srisuwan ◽  
Nuengruetai Kumsri ◽  
Trinet Yingsamphancharoen ◽  
Attaphon Kaewvilai

This work presents the improvement of hardfacing welding for American Society for Testing and Materials (ASTM) A572-based high-strength, low-alloy steel by controlling the heating/cooling conditions of welding process. In the welding process, the buffer and hardfacing layers were welded onto A572-based material by a nickel–chromium electrode and chromium carbide electrode, respectively. The base metal and electrode materials were controlled by the heating/cooling process during the welding to reduce excessive stress, which could result in a crack in the specimens. The welded specimens were examined by visual and penetrant inspections for evaluating the welding quality. The macro–micro structure of the deposited layer was investigated; scanning electron microscope with an energy-dispersive X-ray spectrometer (SEM-EDS) and XRD were used to characterize structural properties, elemental compositions, and crystallite sizes of the welded specimens. The surface properties, such as hardness, impact, and abrasive wear of the welded specimens, were tested for evaluation of the wear resistance of the welded specimens.


2018 ◽  
Vol 80 (3-2) ◽  
Author(s):  
Kowit Lertwittayanon

Disc alumina membrane supports were formed through agar gelcasting method. The agar gelcasting was expected to be environmentally-friendly forming technique using simple equipment. Final agar amounts (0.25 – 0.75wt%) in gelcasting mixtures were varied to find the optimum condition of shaping and the desired microstructure of sintered supports. The gelcasting mixtures were prepared from non-reactive grade Al2O3 and porcelain at the ratio of 98.5:1.5 by weight. The porcelain addition allowed the membrane support to have high strength at lower sintering temperature. When the final agar amounts increased from 0.25 to 0.75wt%, the dried, gelcast supports tended to have rough surface and subsequently resulting in crack. TGA profiles confirmed that there was interaction between agar chains and kaolin particles on cooling the gelcast supports leading to different microstructures after sintering. The final agar amount of 0.5 wt% provided the highest porosity of 48.9% and the highest relative density of 61.5%. Additionally, the average pore size of 1.5 µm was obtained at the final agar amount of 0.5 wt% suitable for using as asymmetric membrane support or microfiltration membrane.   


2007 ◽  
Vol 539-543 ◽  
pp. 2778-2781 ◽  
Author(s):  
Zhen Kai Xie ◽  
Yasuo Yamada ◽  
Takumi Banno

Highly porous materials with a cellular structure are known to have many interesting combinations of physical and mechanical properties, such as very low specific weight combined with high thermal conductivity. However, when the pore size of the foam metal grows, the strength maintenance is scarce because the array of the pore is not uniform. In the present work, micro porous aluminum with porosities between 5% and 50% and pore sizes of 20~50 μm was produced by applying the powder metallurgical technique, i.e. by sintering the aluminum metal powders and PMMA powder mixture at 913 K. The effect of sintering temperature on the compressive properties of porous aluminum was investigated. The effects of particle size and fraction of space holding particle and metal powder on the porosity pore size and mechanical properties of porous sintered specimens were mainly investigated. The pore size of porous aluminum can be controlled by changing the PMMA powder diameter. The results show the fabrication of the micro porous aluminum with middle porosity and high strength is possible.


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