Gas Evolution Rate Research Articles

Unbiased Photoelectrochemical Solar Hydrogen Generation on Highly Stable, Ultrathin Organic Linker/Metal Ions-Treated InGaN Nanorods on Metal

InGaN-based nanostructures have recently been recognized as promising materials for efficient solar hydrogen generation. This is due to their chemical stability, adjustable optoelectronic properties, suitable band edge alignment, and large surface-to-volume ratio. The inherent high density of surface trapping states and the lack of compatible conductive substrates, however, hindered their use as stable photo-catalysts. We have designed, synthesized and tested an efficient photocatalytic system using stable InGaN-based nanorods (NRs) grown on an all-metal stack substrate (Ti-Mo) for a better electron transfer process. In addition, we have applied a bifunctional ultrathin thiol-based organic surface treatment using 1,2-ethanedithiol (EDT), in which sulfur atoms protected the surface from oxidation. This treatment has dual functions, it passivates the surface (by the removal of dangling bonds) and creates ligands for linking Ir-metal ions as oxygen evolution centers on top of the semiconductor. This treatment when applied to InGaN NRs resulted in a photo-catalyst that achieved 3.5% solar-to-hydrogen (STH) efficiency, in pure water (pH~7, buffer solution) under simulated one-sun (AM1.5G) illumination and without electrical bias. Over the tested period, a steady increase of the gas evolution rate was observed from which a turnover frequency of 0.23 s-1 was calculated. The novel growth of InGaN-based NRs on a metal as well as the versatile surface functionalization techniques (EDT-Ir) have a high potential for making stable photo-catalysts with adjustable band gaps and band edges to harvest sun light.

PENGARUH GARAM NaCl TERHADAP KINERJA PROSES BIOLOGIS ANAEROBIK

Anaerobic treatment of synthetic wastewater with a high NaCl content was investigated for its effect on the process. The synthetic wastewater, including NaCl up to 40 g/l, was treated anaerobically by draw-and-fill method at a treatment temperature of 37℃ and volumetric loading of rate TOC of 1 g/l/d. TOC removal efficiency and rate of gas evolution rate gradually decreased as salt content increased, although stable operation was maintained. TOC removal efficiency remained high at concentration of NaCl up to 20 g/l, although it fell to 82 % at 30 g NaCl/l. The gas yield at 10, 20 and 30 g NaCl/l were 1.35; 1.10 and 1.00 l/g-TOC loaded, which corresponded to 96; 83 and 78% of that without NaCl, respectively. The content of methane in the evolved gas was 50 to 55% throughout the experiment. Stable operation could not be maintained at 40 g NaCl/l since the TOC removal efficiency gradually decreased with the rapid increased in levels of volatile fatty acidsKata kunci : fermentasi metana, garam NaCl, konduktifitas, asam-asam organik, biogas

A Spatially Separated Organic–Inorganic Hybrid Photoelectrochemical Cell for Unassisted Overall Water Splitting

The Z-scheme overall solar water splitting is a mimic of natural photosynthesis to convert solar energy into chemical fuels. Despite much effort, the available Z-scheme artificial systems are still rare, and most of them rely on inorganic semiconductors. In this study, inspired by the characteristics of p-type and higher unoccupied molecular orbital level of organic semiconductors, a spatially separated organic–inorganic hybrid Z-schematic photoelectrochemical (PEC) cell for unassisted overall water splitting is developed by wiring inorganic ZnO nanorod arrays photoanode and organic poly(3-hexylthiophene):[6,6]-phenyl-C61-butyric acid (P3HT:PCBM) photocathode in a tandem manner. In the short-circuit configuration, the photocurrent density reaches an initial value of ∼78 μA cm–2 and an average value of ∼95 μA cm–2 under continuous UV–vis light irradiation, giving rise to the solar-to-fuel conversion efficiency of ∼0.12%. The average gas evolution rates are 1.59 μmol h–1 for H2 and 0.75 μmol h–1 for O2 unde...

Fe3O4@SiO2 magnetic nanoparticles for bulk scale synthesis of 4′-chloro-2,2′:6′,2″-terpyridine

Terpyridines are unique class of functional compounds that is extensively spotlighted in diverse fields like synthesis of supramolecular chemistry, nanomaterials, medicinal chemistry intermediates, drugs and active pharmaceutical ingredients and so on. The key challenges for the production of terpyridine lie in the bulk scale synthesis of intermediates. The expansively used synthon for terpyridine synthesis is 4′-chloro-2,2′:6′,2″-terpyridine and their bulk scale synthesis under the ambient conditions using a Fe3O4@SiO2 magnetic nanomaterial catalyst is investigated in the present work. In the protocol stabilized, ethyl-2-pinacolate and acetone were reacted in the presence of NaH to obtain 1,5-bis(2-pyridinyl) pentane-1,3,5-trione. The enolate of acetone is difficult to generate even with NaH and we used Fe3O4@SiO2 to increase the rate of H2 gas evolution. The triketone is cyclized with CH3COONH4 to obtain 2,6-bis(2-pyridinyl)-4-pyridine. This reaction proceeds quantitatively and the off-white solid was easy to isolate from the reaction medium. The subsequent aromatization was observed with PCl5/POCl3 and acidic silica gel promoted the product yield to reach ~78%. The crux of the present protocol is that it does not involve any column purification and significant yield of 4′-chloro-2,2′:6′,2″-terpyridine can be conveniently attained. The Fe3O4@SiO2 aids in the stabilization of carbonyl on the solid support and abstraction of hydrogen from methyl group of acetone. The 40 nm sized Fe3O4@SiO2 favored the maximum yield attributed to the density of active sites to promote the reactions. Due to high value nature of 4′-chloro-2,2′:6′,2″-terpyridine, the nominal 30% yield improvement achieved at the bulk scale gauges significant at the industrial scale.

1-Allyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide as an effective organic additive in aluminum-air battery

In Al-air batteries, the self-corrosion of Al electrodes and the parasitic hydrogen evolution during battery discharge are the major defects that lead to the degradation in the performance of the battery. Here, the ionic liquid (1-Allyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide) (IL) is used as an organic additive to minimize the H2 gas evolution and corrosion rate in the alkaline electrolyte (4.0M NaOH) for Al-air battery. The efficiency of IL compound is investigated using H2 gas evolution, polarization, electrochemical frequency modulation (EFM) and battery performance measurements. The surface morphology of Al electrode was characterized by scanning electron microscopy (SEM) coupled with energy dispersive X-ray (EDX) analysis. The results presented below show that the IL compound inhibits both the H2 gas evolution and the self-corrosion of Al electrode. In addition to this, the presence of IL compound enhances the capacity density of battery reaching to the maximum value (2554 mAhg-1) at 1.5mM of IL.

Unbiased photocatalytic hydrogen generation from pure water on stable Ir-treated In0.33Ga0.67N nanorods

InGaN-based nanostructures have recently been recognized as promising materials for efficient solar hydrogen generation. This is due to their chemical stability, adjustable optoelectronic properties, suitable band edge alignment, and large surface-to-volume ratio. The inherent high density of surface trapping states and the lack of compatible conductive substrates, however, hindered their use as stable photo-catalysts. We have designed, synthesized and tested an efficient photocatalytic system using stable In0.33Ga0.67N-based nanorods (NRs) grown on an all-metal stack substrate (Ti-Mo) for a better electron transfer process. In addition, we have applied a bifunctional ultrathin thiol-based organic surface treatment using 1,2-ethanedithiol (EDT), in which sulfur atoms protected the surface from oxidation. This treatment has dual functions, it passivates the surface (by the removal of dangling bonds) and creates ligands for linking Ir-metal ions as oxygen evolution centers on top of the semiconductor. This treatment when applied to In0.33Ga0.67N NRs resulted in a photo-catalyst that achieved 3.5% solar-to-hydrogen (STH) efficiency, in pure water (pH~7, buffer solution) under simulated one-sun (AM1.5G) illumination and without electrical bias. Over the tested period, a steady increase of the gas evolution rate was observed from which a turnover frequency of 0.23s-1 was calculated. The novel growth of InGaN-based NRs on a metal as well as the versatile surface functionalization techniques (EDT-Ir) have a high potential for making stable photo-catalysts with adjustable band gaps and band edges to harvest sun light.

Al-6013-T6 and Al-7075-T7351 alloy anodes for aluminium-air battery

This study is aimed to determine the appropriate anode material (pure Al, 6013-T6; Al1 and 7075-T7351; Al2) for Al-air batteries. Electrochemical Measurements, Galvanostatic Anodic Dissolution Test and Surface Characterization are performed. The corrosion rate and the hydrogen gas evolution rate are calculated. Anodic dissolution test is carried out at the current density of 10–50 mA cm−2. The weight loss measurements were performed. The anode utilization (Ua%) and capacity density are calculated. The surface morphology of electrodes is investigated by scanning electron microscope (SEM) and mapping imagines are taken. The surface analysis also is performed by energy dispersive X-ray spectrometer (EDS) and contact angles are determined by Young–Laplace Contact Angle method. As a result, it is seen that alloy elements change the surface characteristics during discharging of the battery and the battery performance is positively affected. Especially, copper shows surprisingly synergistic effect with aluminium on the alloy surface.

Gas Evolution and Capacity Fading in LiFexMn1-xPO4/Graphite Cells Studied by Neutron Imaging and Neutron Induced Prompt Gamma Activation Analysis

The gas evolution in LFP/graphite and LFMP/graphite cells during the formation has been analyzed via neutron imaging (NI). The results show that in LFMP/graphite cells approximately 30% more gas is generated in comparison to LFP/graphite and stronger gas evolution is associated with the presence of Mn. For the LFP/graphite cell two different linear phases in gas evolution rate can be detected while LFMP/graphite cells reveal an additional phase. In both full-cells a distinct relation between gas evolution and electrode potentials has been determined. Additional neutron induced Prompt Gamma Activation Analysis (PGAA) measurements were carried out in order to correlate long-term Mn dissolution and capacity retention. Long-term cycling showed higher capacity retention for the LFMP/graphite cells. The results of PGAA prove that Mn dissolution decreases rapidly with increased cycle number and the Mn dissolution rate of LFMP is far below values observed for oxide-type cathode materials. Long-term cycling showed that the negative effects of higher irreversible capacity loss in the formation step and more gas evolution of LFMP/graphite cells in comparison to LFP/graphite cells is compensated after several cycles due to higher capacity retention.

Kinetics of Gas Emission from Heated Moulding Sands Together with the On-line Assessment of H2 and O2 Fractions - New Investigation Method

Abstract The new investigation method of the kinetics of the gas emission from moulding sands used for moulds and cores is presented in this paper. The gas evolution rate is presented not only as a function of heating time but also as a function of instantaneous temperatures. In relation to the time and heating temperature the oxygen and hydrogen contents in evolving gases was also measured. This method was developed in the Laboratory of Foundry Moulds Technology, Faculty of Foundry Engineering, AGH. Gas amounts which are emitted from the moulding sand at the given temperature recalculated to the time unit (kinetics) are obtained in investigations. Results of investigations of moulding sand with furan resin are presented - as an example - in the paper.

State of Spent Molding Sands in the Mold Large-Size Cast

Abstract The results of investigations of spent moulding sands taken from the mould at various distances from the surface of the produced casting, are presented in the paper. The casting mould was made with an application of the cooling system of the metal core in order to increase the cooling rate of the ladle casting. As temperature measurements in the mould indicated the heat flow from the metal did not create conditions for the complete burning of a moulding sand. The analysis was performed to find out changes of spent moulding sands caused by degradation and destruction processes of organic binders. Conditions occurring in the casting mould were discussed on the bases of testing: ignition losses, dusts contents, pH reactions and the surface morphology of the moulding sand samples. Factors limiting the effective mould degassing were pointed out. Operations, possible for realization, which can limit the reasons of a periodical occurrence of increased amounts of casting defects due to changing gas evolution rates being the result of the technological process, were also indicated.

Gas Evolution Rates of Graphite Protective Coatings in Dependence on the Applied Solvent and Kind of Atmosphere

Abstract The results concerning emission of gases from two commercial graphite protective coatings for moulds and cores (water and alcoholic) are given in the hereby paper. Investigations were performed in two systems. One of the systems was corresponding to conditions occurring inside the mould cavity immediately after its pouring with liquid metal (Method 1), while the second was simulating conditions deep inside the mould at a certain distance from the casting (Method 2). Investigations were carried out in the CO2 atmosphere and in the air. The water protective coating generated 1.5 to 3 times larger volume of gases than the alcoholic coating (in dependence on the measuring method and atmosphere). The smallest differences occurred in the air atmosphere, while the largest in the CO2 atmosphere.

Li2O–ZnO–Co3O4–TiO2 composite thin-film electrocatalyst for efficient water oxidation catalysis

ABSTRACTThin films of different Li2O–ZnO–Co3O4–TiO2 (LZCT) compositions were prepared and employed as electrocatalysts (i.e., anodes) to perform water oxidation reaction (WOR). The electrocatalytic activities of these thin films were compared with those exhibited by the sodium salt of cobalt phosphate (Na2CoP2O7) (CP) thin-film electrocatalyst, which is a well-known water oxidation catalyst (WOC). These results suggest that the 10Li2O–10ZnO–40Co3O4–40TiO2 composition exhibits a better catalytic activity in terms of higher faradaic efficiency (>98%), lower over potentials (<400 mV), higher reaction stability (up to 30 continuous cyclic voltammetry (CV) cycles), and the rate of O2 and H2 gas evolution in terms of current density (about 1 mA/cm2) in comparison with those exhibited by CP thin-film electrocatalyst. Furthermore, these LZCT thin films exhibited very high specific surface area values and due to the unique microstructure of ZnCo2O4 phase evolved out of these LZCT compositions at a calcination temperature of 550°C for 30 min it has been found to be responsible for the higher specific surface area values measured for these thin-film compositions.

Gas evolution rates – A critical uncertainty in challenged gas-liquid separations

While much of gas-liquid separation is considered a mature technology, key challenges remain in designing compact systems – particularly for subsea applications – and heavy oil service. Separator performance is critically important for the safe and reliable operation of downstream equipment. Incomplete removal of gas from liquid, or gas carry-under, may result in unexpected pump cavitation, hydrate formation, erosion, and slugging. Liquids entering the separator often carry entrained gas bubbles. Moreover, some of the gas remains dissolved, governed by thermodynamics, as solution gas in the liquid. Thermodynamics dictates that after a pressure drop, seen often upstream of separation, some of the solution gas must evolve out of the liquid. This process is generally assumed, without basis, to be instantaneous. Thus, conventional separator design only accounts for the entrained gas bubbles in the liquid, in addition to bulk separation. Therefore, the kinetics of solution gas evolution is a critical uncertainty in gas-liquid separator design. In compact separators or heavy oil service, the rates of gas evolution are particularly important design parameters. This review discusses the limited reports on this phenomenon, identifies pertinent insights from other areas, highlights gaps in the current understanding, and proposes a path forward.

Impact sensitivity of energy systems based on nanoporous silicon and oxidant: influence of the hydrogen content and specific surface

The impact sensitivity of the energy systems based on nanoporous silicon, obtained by electrochemical etching of monocrystalline silicon wafers in an HF-containing electrolyte, and calcium perchlorate was studied using a modified Weller—Ventselberg technique (estimation of the impact sensitivity of initiating explosives). The impact sensitivity of these systems is shown to be determined by both the presence of hydrogen, which is stored on the porous silicon surface during the preparation of the latter, and also the influence of other factors, including the specific surface of porous silicon. The composition, amount of the generated gas, and gas evolution rate during nonisothermal and isothermal calcination of porous silicon in a temperature range of 60—120 °С were determined using methods of thermal gravimetry (TG), measurement of the gas volume, and mass spectrometry. The generated gas almost completely consists of hydrogen, and its content in the studied samples of porous silicon achieved ~3.8 wt.%. The calculated activation energy of the hydrogen evolution process in vacuo was 103.7±3.3 kJ mol–1. The dependences of the impact sensitivity of the energy composition based on porous silicon and heat of combustion of porous silicon on oxygen on the hydrogen content were established. The impact sensitivity of the energy system decreases with a decrease in the hydrogen content in porous silicon and its specific surface.

Water Electrolysis Using Water Absorbing Porous Electrolyte Cell

We have reported so far water electrolysis by use of a water absorbing porous electrolyte that works under similar conditions to a polymer electrolyte electrolysis cell (PEEC) [1]. This cell consist of a surface-proton conducting metal oxide nanoparticles as proton-conducting electrolyte, a controlled-hydrophobic electrocatalytic layer, and fully hydrophobic gas diffusion layer (GDL) to generate pressurized hydrogen and oxygen gases. In this presentation, we will discuss the optimized preparation condition for membrane electrode assembly (MEA), which consist of electrolyte, electrode, and GDL layers. We also show that the hydrogen gas generation rate depend on the supplied water pressure (ΔP).MEA of the water electrolysis cell is prepared as follows: The GDL films were formed by compressing of acetylene black/poly(tetrafluoroethylene) (PTFE) (=1/6, weight ratio) composite powder using Newton Press under 6 kN cm-2 for 1 min and successive heat treatment at 360 °C for 15 min. Electrode part with Pt loading of 2.0 mg cm-2 on top of the GDL films was formed using hot-press at 300 °C for 3 min under 300 kgf cm-2, which is consisted of consisted of platinum carbon (Pt/C) / PTFE / titanium phosphate ionomer composite. Finally, electrolyte layer on top of electrode layer was prepared by coating of titanium sulfonate/Nafion (=9/1, weight ratio) slurry and hot-pressing at 140 °C under 100 kgf cm-2 for 1 min. The fabricated MEAs were different sizes with diameters of 30 mm and 12 mm for anode and cathode sides, respectively. The current-voltage characteristic and generation hydrogen gas is measured by putting the fabricated MEA into the cell as shown Figure 1. The distilled water is supplied from cathode side and is pressurized using nitrogen gas in the ΔP range from 0 MPa to 0.25 MPa. The gas evolution rates of hydrogen during water electrolysis were evaluated by gas chromatography to be determined by 1% hydrogen/argon calibration curve. The gas evolution rate of hydrogen increased with increasing ΔP from 0 MPa to 0.10 MPa, and reaches a maximum value at 0.15 MPa. At ΔP higher than 0.15 MPa, the rates decreased to almost the same value at 0 MPa. We supposed that the generated gas was leaked to outside of the cell in lower pressure region than 0.15 MPa. On the other hand, in higher region than 0.15 MPa, the generated gas in the water phase by water electrolysis was not completely separated to gas phase. The obtained evolution rate was compatible with the theoretical value calculated by Faraday’s law. However, electrolysis voltages were high compared with conventional PEEC. Possible reason is inhomogeneous state of electrode layer and electrolyte layer with lower electrical conductivity. Acknowledgements This work was supported by CREST in JST. References (1) S.-J. Kim, T. Sakai, H. Oda, J.-I Hamagami, Y. Okuyama, M. Matsuka, S. Ohta, Y. Shimizu, T. Ishihara, H. Matsumoto Electrochem. 2012 80(4), 246. Figure 1

Chemical Reaction between Boric Acid and Phosphine Indicates Boric Acid as an Antidote for Aluminium Phosphide Poisoning.

Aluminium phosphide (AlP) is a fumigant pesticide which protects stored grains from insects and rodents. When it comes into contact with moisture, AlP releases phosphine (PH3), a highly toxic gas. No efficient antidote has been found for AlP poisoning so far and most people who are poisoned do not survive. Boric acid is a Lewis acid with an empty p orbital which accepts electrons. This study aimed to investigate the neutralisation of PH3 gas with boric acid. This study was carried out at the Baharlou Hospital, Tehran University of Medical Sciences, Tehran, Iran, between December 2013 and February 2014. The volume of released gas, rate of gas evolution and changes in pH were measured during reactions of AlP tablets with water, acidified water, saturated boric acid solution, acidified saturated boric acid solution, activated charcoal and acidified activated charcoal. Infrared spectroscopy was used to study the resulting probable adduct between PH3 and boric acid. Activated charcoal significantly reduced the volume of released gas (P <0.01). Although boric acid did not significantly reduce the volume of released gas, it significantly reduced the rate of gas evolution (P <0.01). A gaseous adduct was formed in the reaction between pure AlP and boric acid. These findings indicate that boric acid may be an efficient and non-toxic antidote for PH3 poisoning.

Solvent, Lithium Salt and Temperature Influence on Stability of Carbonate Based Electrolytes for 5 V LiNi0.5Mn1.5O4

Spinel LiNi0.5Mn1.5O4 (LNMO) is one of the most promising next-generation cathode candidates for Li-ion batteries because of its reversible specific charge of 147 mAh/g and a high operating potential of 4.7 V.[1] However, the cycling performance of high-voltage cathodes is limited by the poor anodic stability of the most commonly employed alkyl carbonate electrolytes, e.g. ethylene carbonate (EC) and dimethyl carbonate (DMC).[2] Increasing attention is paid to alkyl carbonate based electrolytes for high-voltage applications, including the selection of co-solvents, additives, the role of lithium salt and possible catalytic effect from the electrode components. The presented work focuses on the investigation of electrolyte decomposition mechanisms and consequent gas evolutions from LNMO cathode by applying in situ gas analysis techniques, i.e. in situ pressure characterization and online electrochemical mass spectrometry (OEMS).[3] The major detected volatile species include H2, CO, CH3F, CO2, and POF3 (only with LiPF6 salt), which present gas evolution profiles depending on the electrochemical potential and electrolyte composition. Enhanced gas evolution rates are observed by increasing DMC content, exchanging LiPF6 salt to LiClO4 or increasing the cell temperature.[4] Ni cations with different oxidation states on the LNMO surface preliminarily exhibit dissimilar catalytic efficiency towards electrolyte decomposition. Our in situ gas analysis provides valuable insights into electrolyte degradation processes on LNMO cathodes, thus further assisting intensive efforts to enhance both performance and safety of high-voltage Li-ion batteries. [1] C. M. Julien and A. Mauger, Ionics, 19, 951 (2013). [2] D. Aurbach, B. Markovsky, Y. Talyossef, G. Salitra, H.-J. Kim and S. Choi, Journal of Power Sources, 162, 780 (2006). [3] M. He, E. Castel, A. Laumann, G. Nuspl, P. Novák and E. J. Berg, Journal of The Electrochemical Society, 162, A870 (2015). [4] M. He, L. Boulet-Roblin, P. Borel, C. Tessier, P. Novák, C. Villevieille and E. J. Berg, Journal of The Electrochemical Society, 163, A83 (2016).

Investigation of high‐level waste glass melting using X‐ray computed tomography

AbstractA method has been developed to quantitatively assess the melting behavior of simulated nuclear waste glasses in a 5‐cm‐diameter stainless steel beaker heated from the bottom. The method applies X‐ray scanning and computed tomography to build three‐dimensional volumetric data of a heat‐treated sample and performs an adaptive segmentation analysis of the volumetric data to identify morphologically distinct regions in the sample matrix and quantify the amount of material in each region based on computed tomography density. The method was applied to two different series of simulated high‐level waste glass melter feeds, and the results showed that it provides detailed images of samples at various stages of melting, including distribution of gas bubbles of varying sizes within the sample matrix, as well as a quantitative measure of how fast various waste/frit feeds melted relative to each other. The results show that the melting rate is influenced by the rate of calcine gas evolution, melt viscosity, and the presence of modifier ions in the feed.

Solar-Driven Water Oxidation and Decoupled Hydrogen Production Mediated by an Electron-Coupled-Proton Buffer.

Solar-to-hydrogen photoelectrochemical cells (PECs) have been proposed as a means of converting sunlight into H2 fuel. However, in traditional PECs, the oxygen evolution reaction and the hydrogen evolution reaction are coupled, and so the rate of both of these is limited by the photocurrents that can be generated from the solar flux. This in turn leads to slow rates of gas evolution that favor crossover of H2 into the O2 stream and vice versa, even through ostensibly impermeable membranes such as Nafion. Herein, we show that the use of the electron-coupled-proton buffer (ECPB) H3PMo12O40 allows solar-driven O2 evolution from water to proceed at rates of over 1 mA cm–2 on WO3 photoanodes without the need for any additional electrochemical bias. No H2 is produced in the PEC, and instead H3PMo12O40 is reduced to H5PMo12O40. If the reduced ECPB is subjected to a separate electrochemical reoxidation, then H2 is produced with full overall Faradaic efficiency.

Performance of water-soluble composite sulfate sand core for magnesium alloy castings

A novel water-soluble sand core hardened by twice microwave heating was fabricated using composite solution of magnesium sulfate and sodium sulfate as a binder. The tensile strength, water absorption rate, gas evolution and water-soluble rate of the water-soluble composite sulfate sand core (WCSSC) were studied. The micro-morphology of WCSSC was observed by scanning electron microscope (SEM). The results show that tensile strength of WCSSC is 1.2MPa, and the 4h storage tensile strength exceeds 1MPa, and also the water-soluble rate is about 42.65kg/(minm2), which indicates that WCSSC possesses good moisture resistance and water-soluble collapsibility. The microscopic analysis demonstrates that there are some micro-cracks or holes in the bonding bridge that decreases the strength of WCSSC after being put in humidistat for several hours.