Performance Analysis of Sulfate Pisha-Sandstone Cement Soil Based on the Grey Entropy Theory

Kaiqiang Geng,Xiaoli Li 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.2

The exploitation of Pisha sandstone is one of the most significant strategies for environmental protection and resource saving in the border areas of Shanxi, Shaanxi, and Inner Mongolia, where Pisha sandstone is widely distributed. The goal of this research was to develop a method by which to transform Pisha sandstone cement soil into a new type of material which could be applied in saline regions, thereby achieving a wider application. The micro-pore and structural characteristics of cement soil samples which had been soaked in 0.5 mol/L of sodium sulfate solution were analyzed using nuclear magnetic resonance (NMR), X-ray diffraction (XRD), and scanning electron microscopy methods (SEM). The results showed that the compressive strength of the sandstone cement soil decreased with the increase in the sulfate intrusion days. Under the erosion of sodium sulfate solution, the lower the cement content was, the more quickly the strength decreased. The main mineral composition diffraction peaks of sulfate sandstone, along with the diffraction peaks of sulfate corrosion products, tended to change during salt invasion. The mineral components in the sandstone can provide a material basis for the formation of the sulfate erosion products of cement soil. In addition, the grey entropy theory can be utilized to explore the correlation degree of the porosity, T2 spectrum area, bound fluid saturation, free fluid saturation, and unconfined compressive strength of the specimen. The results obtained in this research investigation provided a theoretic basis for the practical engineering applications of Pisha-sandstone cement soil in saline regions.

Effects of Electrolyte Temperature during Anodization on Properties of ZrO₂-coated Al Foils

Kaiqiang Zhang,Sang-Shik Park 한국진공학회(ASCT) 2019 Applied Science and Convergence Technology Vol.28 No.6

The effects of electrolyte temperature during anodization on the microstructure and electrical properties of the ZrO₂ coated Al foils were investigated. The specimens were prepared by coating ZrO₂ sol on etched Al foils and anodization in MPD-boric acid electrolytes at 30, 60, and 90 ℃, respectively. Anodization potential was 700 V. The thickness of oxide layer anodized increased with increasing the electrolyte temperature. In contrast, the crystallization of ZrO2 and Al₂O₃ decreased at higher anodizing temperature. Compared with the specific capacitance of the sample anodized at 90 ℃, the specific capacitances of which anodized at 30 and 60 ℃ are enhanced about 12.8 % and 8.8 %, respectively. Therefore, the anodization at 30 ℃ can effectively improve the specific capacitance of the samples, and save the thermal energy during anodization.

S@GO as a High‑Performance Cathode Material for Rechargeable Aluminum‑Ion Batteries

Kaiqiang Zhang,Tae Hyung Lee,Joo Hwan Cha,Ho Won Jang,Mohammadreza Shokouhimehr,Ji-Won Choi 대한금속·재료학회 2019 ELECTRONIC MATERIALS LETTERS Vol.15 No.6

Aluminum-ion batteries (AIBs) are considered promising post lithium-ion batteries owing to their outstanding safety, gravimetricand volumetric capacities, and cost efficiency advantages. However, one practical obstacle to their development isthe lack of reliable cathode materials that can be coupled with the distinguished Al anode. To address this issue, we synthesizeda S@GO composite material for use as a cathode material in AIBs. The synthesized S@GO material exhibits a rodstructure with a diameter of around 100 nm. Inside these nanorods, sulfur nanoparticles with a size of around 5 nm wereuniformly anchored on the graphene sheets. By taking the advantage of an introduction of graphene sheets, the capacitieswere significantly preserved, displaying a capacity that was more than double that of a bare S active material. In addition,a 3000-cycle long-term repeated charge/discharge measurement exhibited extremely stable capacity values with a highCoulombic efficiency of 98% at the 3000th cycle. The charge/discharge processes were clearly shown during the repeatedcycling measurement at a high current density of 1000 mA g−1. This work is expected to stimulate further study of elementalS used as a cathode material for high-performance AIBs.

A Hybrid Energy Storage Mechanism of Zinc Hexacyanocobaltate-Based Metal–Organic Framework Endowing Stationary and High-Performance Lithium-Ion Storage

Kaiqiang Zhang,Tae Hyung Lee,Ho Won Jang,Mohammadreza Shokouhimehr,Ji‑Won Choi 대한금속·재료학회 2019 ELECTRONIC MATERIALS LETTERS Vol.15 No.4

Lithium-ion batteries (LIBs) are considered to be theoretically promising with regard to large-scale energy storage and conversionsystems. However, a significant problem is the lack of cost-efficient high-performance cathode materials for LIBs. Inthis study, we demonstrate a Prussian blue analog, zinc hexacyanocobaltate (ZnHCCo), as the low-cost and high-performancecathode material for LIBs. The open-framework crystal structure of ZnHCCo contributes toward reversible cation insertionand extraction along with the spontaneous valence change of hosts. Specifically, the as-prepared ZnHCCo exhibits a highlyreversible capacity of 121.5 mAh g−1 at a current density of 1.25 C, a superior rate capability of 60.5 mAh g−1 at 6.25 C,and a stable cycling stability with a Coulombic efficiency of 96.5%. Therefore, the well-crystallized and low-cost ZnHCCois expected to be a potential cathode material for LIBs used in grid-scale energy storage and conversion systems. In addition,the synthesis process of the electrode material can be readily up scaled using the earth abundant and environmentally benignprecursors via a room-temperature wet-chemical method.

Properties of CoS2/CNT as a Cathode Material of Rechargeable Aluminum‑Ion Batteries

Kaiqiang Zhang,Tae Hyung Lee,Joo Hwan Cha,Ho Won Jang,Mohammadreza Shokouhimehr,Ji-Won Choi 대한금속·재료학회 2019 ELECTRONIC MATERIALS LETTERS Vol.15 No.6

Aluminum ion batteries (AIBs) are considered, in principle, promising post-lithium-ion batteries, which are potential forusing in grid-scale energy storage and electric vehicles, owing to the economic Al. The inflammable ionic liquid electrolyteendows stable plating and stripping of Al ions. A spotlighted research on cathode material has been preforming to obtain ahigh-performance cathode material that can match well with the prominent Al foil. However, one over-looked factor for thestudy of cathode materials is the cost and possibility of mass-production. With this key point in mind, we as the forerunnerstudied the CoS2/carbon nanotubes (CNTs) composite cathode material composed of low cost and commercialized CoS2and multi-wall CNTs to promote the development of AIBs. Stable charge/discharge plateaus (at 1.2/0.9 V vs. AlCl4−/Al)during cycling test were obtained for the CoS2/CNTs product at a high current density of 1000 mA g−1, with an extremelyhigh Coulombic efficiency of 98% and reasonable electrochemical capacities. This report is expected to contribute morecontribution in the development of cathode materials for rechargeable AIBs.

Integrative metabolome and transcriptome analyses reveal the differences in flavonoid and terpenoid synthesis between Glycyrrhiza uralensis (licorice) leaves and roots

Kaiqiang Yu,Li Peng,Wenyu Liang,Jing Shi,Guoqi Zheng,Hong Wang,Xinhua Liang,Shijie Wu 한국식품과학회 2024 Food Science and Biotechnology Vol.33 No.1

Licorice from Glycyrrhiza uralensis roots is used in foods and medicines. Although we are aware that licorice roots and leaves have distinct material compositions, the specific reasons for these differences remain unknown. Comparison of the metabolomes and transcriptomes between the leaves and roots revealed flavonoids and triterpenoid saponins were significantly different. Isoflavones were enriched in roots because of upregulation of genes encoding chalcone isomerase and flavone synthase, which are involved in isoflavone synthesis. Six triterpenoid saponins were significantly enriched only in the roots. The leaves did not accumulate glycyrrhetinic acid because of low expression levels of genes involved in its synthesis. A gene encoding a UDP glycosyltransferase, which likely catalyzes the key step in the transformation of glycyrrhetinic acid to glycyrrhizin, was screened. Our results provide information about the differences in flavonoid and triterpenoid synthesis between roots and leaves, and highlight targets for genetic engineering.

Effects of ZrO₂ sol concentration on microstructure and electrical properties of ZrO₂-Al₂O₃ dielectrics formed on Al foils

Zhang, Kaiqiang,Park, Sang-Shik Elsevier 2018 Surface & coatings technology Vol.342 No.-

<P><B>Abstract</B></P> <P>The effects of ZrO<SUB>2</SUB> sol concentration on the microstructure and electrical properties of ZrO<SUB>2</SUB>-Al<SUB>2</SUB>O<SUB>3</SUB> dielectrics on etched Al foils are studied. The experiment is carried out by coating the surface of etched Al foils with ZrO<SUB>2</SUB> sol with a series of concentrations and anodizing in the 2-methyl-1,3-propanediol (MPD)-boric acid electrolyte at 700, 800, and 900 V. The increase in the thickness of the ZrO<SUB>2</SUB>-coated layer with increasing ZrO<SUB>2</SUB> sol concentration causes a reduction in the total thickness of dielectrics. The tetragonal-to-monoclinic ZrO<SUB>2</SUB> phase change can be induced by anodization and the increase in the crystalline size of tetragonal ZrO<SUB>2</SUB>. The Zr-Al-O composite layer after anodization exhibits a microstructure that is a combination of the microstructures of separated high-permittivity crystalline ZrO<SUB>2</SUB> and amorphous high-resistivity Al<SUB>2</SUB>O<SUB>3</SUB>. The optimal ZrO<SUB>2</SUB> sol concentration is 1.3 M, and the specific capacitances increased by 38% for 700 V, 40% for 800 V, and 66% for 900 V compared with those of non-coated samples.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The tetragonal-to-monoclinic ZrO<SUB>2</SUB> phase change is induced by anodization. </LI> <LI> ZrO<SUB>2</SUB> sol concentration affects the total thickness of dielectrics after anodization. </LI> <LI> The optimal ZrO<SUB>2</SUB> sol concentration is 1.3 M. </LI> <LI> Capacitances of ZrO<SUB>2</SUB> coated specimens increased by 38–66%. </LI> </UL> </P>

Effects of borate polyester mixed with water on anodizing behavior and electrical properties of ZrO₂-coated Al foil

Zhang, Kaiqiang,Park, Sang-Shik Elsevier 2017 THIN SOLID FILMS - Vol.636 No.-

<P><B>Abstract</B></P> <P>ZrO<SUB>2</SUB>-Al<SUB>2</SUB>O<SUB>3</SUB> composite oxide film is a promising dielectric material for future application in aluminum electrolytic capacitors. Herein, ZrO<SUB>2</SUB>-Al<SUB>2</SUB>O<SUB>3</SUB> composite oxide films are prepared on etched Al foils via ZrO<SUB>2</SUB> sol-gel coating and anodization. Generally, Al foil anodization is performed in an aqueous boric acid electrolyte. However, if the Al foils are anodized above approximately 700V, a boric acid solution is unsuitable for use as an electrolyte, because it facilitates O<SUB>2</SUB> evolution. Therefore, in this study, we use a borate polyester solution as an electrolyte for anodization at a relatively high voltage, and discuss the effects of the borate polyester concentration on the anodization behavior and electrical properties of the ZrO<SUB>2</SUB>-coated Al foils. The results suggest that a borate polyester electrolyte with high resistivity is suitable for use in high-voltage anodization, as it effectively increases the sample withstanding voltage. Further, the specific capacitances of the samples decrease as the borate polyester to water ratio increases; the most suitable ratio is found to be 0.4. Relative to those of samples anodized in boric acid solution, the specific capacitances of the samples anodized in the borate polyester electrolyte with a 0.4 mixing ratio are increased by 12.7%, 8.9%, and 43.3% for 700, 800, and 900V, respectively.</P> <P><B>Highlights</B></P> <P> <UL> <LI> After anodization of the ZrO<SUB>2</SUB> coated foils, Al<SUB>2</SUB>O<SUB>3</SUB>-ZrO<SUB>2</SUB> composite oxide is formed. </LI> <LI> The most suitable mixing ratio of borate polyester to water is 0.4. </LI> <LI> Increasing the ratio of borate polyester to water enhances the withstanding voltage. </LI> <LI> The specific capacitance of the sample anodized at 900V is increased by 43.3%. </LI> </UL> </P>

Tailorable Topologies for Selectively Controlling Crystals of Expanded Prussian Blue Analogues

Zhang, Kaiqiang,Lee, Tae Hyung,Noh, Hyunho,Farha, Omar K.,Jang, Ho Won,Choi, Ji-Won,Shokouhimehr, Mohammadreza American Chemical Society 2019 Crystal Growth & Design Vol.19 No.12

<P>Chemical manipulations of Prussian blues and Prussian blue analogues (PBAs) beyond first-row transition-metal cations have remained quite preliminary to this day. The presented report demonstrates the feasibility of using different types of cations, including general transition-metal ions, p region elements in the periodic table, lanthanide elements, and overlooked cations such as Al<SUP>3+</SUP> and Mo<SUP>3+</SUP> to build unique PBAs. A systematic study of the different types of PBAs is provided in terms of physical and chemical features by means of transition electron microscopy, X-ray photoelectron spectroscopy, and X-ray absorption near-edge structure. Diverse PBAs can be synthesized with different morphologies. The [Ni(CN)<SUB>4</SUB>]<SUP>2-</SUP>-based PBAs mainly exhibited layered products owing to their 4-fold-coordinated anions. The 6-fold-coordinated anion-based PBAs displayed cubic or distorted cubic crystal structures following the same method of ion arrangements with conventional [Fe(CN)<SUB>6</SUB>]<SUP>2-/3-</SUP>-based PBAs. Furthermore, bonding conditions are greatly affected by the introduced cations. In addition, the PBAs constructed using cations with more unpaired free electrons displayed intense paramagnetic performance. This study provides discoveries regarding innovative PBAs and gives new insights into materials exploration for different target applications.</P><P>Crystal growth and performances of the expanded Prussian blue analogues.</P> [FIG OMISSION]</BR>

Effects of 2-methyl-1, 3-propanediol in boric acid solution on the anodizing behavior and electrical properties of ZrO₂-coated Al foil

Zhang, Kaiqiang,Park, Sang-Shik Elsevier 2017 Surface & Coatings Technology Vol.310 No.-

<P><B>Abstract</B></P> <P>Zr-Al<SUB>2</SUB>O<SUB>3</SUB> composite oxide films are promising dielectric materials for future use in aluminum (Al) electrolytic capacitors. The films were prepared on etched Al foil samples by ZrO<SUB>2</SUB> sol-gel coating and anodizing. To inhibit O<SUB>2</SUB> evolution during anodization, 2-methyl-1, 3-propanediol (MPD) was used with boric acid solution as an electrolyte. In this study, we investigated the effects of the ratio of MPD in boric acid solution on the anodizing behaviors and electrical properties of ZrO<SUB>2</SUB>-coated Al foil. The thickness of the Al<SUB>2</SUB>O<SUB>3</SUB> layer decreased as the MPD ratio increased. The MPD-boric acid solution effectively inhibited O<SUB>2</SUB> evolution. The samples anodized in MPD-boric acid electrolyte with a ratio of 3:10 (volume %) exhibited the highest specific capacitance. Relative to those of samples anodized in boric acid solution, the specific capacitances of samples analyzed in the MPD-boric acid electrolyte increased by 45.5% at 700V, 40.0% at 800V, and 66.7% at 900V.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The total thickness of the oxide layer decreased as the MPD-boric acid electrolyte ratio increased. </LI> <LI> The crystallinities of the Zr-Al<SUB>2</SUB>O<SUB>3</SUB> composite layer decreased as the MPD-boric acid ratio increased. </LI> <LI> Increasing the MPD-boric acid electrolyte ratio effectively enhanced the withstanding voltage. </LI> <LI> The specific capacitance of sample was maximized by anodization in 3:10 MPD-boric acid electrolyte. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>