Graphene edges with a zigzag-type atomic structure can theoretically produce spontaneous spin polarization despite being a critical-metal-free material. We have demonstrated this in graphene nanomeshes (GNMs) with hon...Graphene edges with a zigzag-type atomic structure can theoretically produce spontaneous spin polarization despite being a critical-metal-free material. We have demonstrated this in graphene nanomeshes (GNMs) with honeycomb-like arrays of low-defect hexagonal nanopores by observing room-temperature ferromagnetism and spin-based phenomena arising from the zigzag-pore edges. Here, we apply extremely high electric fields to the ferromagnetic (FM) GNMs using an ionic-liquid gate. A large on/off-ratio for hole current is observed for even small applied ionic-liquid gate voltages (Vig). Observations of the magnetoresistance behavior reveal high carrier densities of ~1013 cm-2 at large Vig values. We find a maximum conductance peak in the high -Vig region and its separation into two peaks upon applying a side-gate (in-plane external) voltage (Vex). It is discussed that localized edge-π band with excess-density electrons induced by Vig and its spin splitting for majority and minority of spins by Vex (half-metallicity model) lead to these phenomena. The results must realize critical-element-free novel spintronic devices.展开更多
Five new tetrasubstituted imidazoles were designed with outstanding yields(83%-92%)in the occurrence of ionic liquid-based-pyridinium as a catalyst.The constructions of all synthesized derivatives were established by ...Five new tetrasubstituted imidazoles were designed with outstanding yields(83%-92%)in the occurrence of ionic liquid-based-pyridinium as a catalyst.The constructions of all synthesized derivatives were established by spectral tools and their purities were verified using thin-layer chromatography(TLC),displaying single-spot.The performance of corrosion protection of the prepared imidazole derivatives was examined theoretically and practically for acid steel corrosion.The experimental study was conducted by electrochemical(electrochemical impedance spectroscopy(EIS)and Tafel polarization(PPS))tools.The findings from the used approaches concluded that the synthesized compounds were wellorganized inhibitors with an efficiency of 90.7%-98.5%at 50℃and 0.7 mmol·L^(-1).The Tafel polarization results indicate the protective action of the additives was under mixed-monitoring.The additive adsorption on the electrode interface performed as a distinguished aspect for protection.The surface exploration on the blank and protected metal was completed by field emission scanning electron microscopy(FESEM).Computational studies by Monte Carlo(MC)simulation and quantum chemical calculation(DFT)were related to practical findings.The corrosion protection adsorption mechanism was reinforced by the preferable fitted Langmuir isotherm model.All findings from the applied-inspected approaches alternately confirm each other.展开更多
In this present paper, the result of C6-C12 α-olefins oligomerizaton in the presence of recyclable chloroaluminate type ionic-liquid catalysts and their combination with Ti-containing complexes is presented. By diffe...In this present paper, the result of C6-C12 α-olefins oligomerizaton in the presence of recyclable chloroaluminate type ionic-liquid catalysts and their combination with Ti-containing complexes is presented. By different methods of analysis the composition and structure of oligoalkylnaphtenic products obtained in the presence of ionic-liquid catalysts and Ti-containing modifiers have been studied.展开更多
Asparagus(Asparagus officinalis)is a high-value low-calorie vegetable with array of bioactive compounds.Asparagus processing nevertheless generates substantial quantity of by-products;their valorization is of utmost i...Asparagus(Asparagus officinalis)is a high-value low-calorie vegetable with array of bioactive compounds.Asparagus processing nevertheless generates substantial quantity of by-products;their valorization is of utmost importance for the sustainability of the industry.Here,feasibility of using four imidazolium-based ionic liquids and their combinations as well as water and methanol to extract bioactive compounds from asparagus leafy by-product was investigated.Effectiveness of ultrasound-microwave-assisted heating to augment extraction was also assessed.1-ethyl-3-methylimidazolium-bromide(EMIMBr)resulted in the highest extraction yield of rutin(25.7 mg/g),which is the most abundant compound in the by-product;such a yield was comparable to that achievable via methanol extraction.Ultrasound-microwave-assisted extraction did not show significant improvement in rutin yield when EMIMBr was used.Interestingly,although methanolic extract exhibited slightly higher content of rutin,it also contained the higher number of impurities;EMIMBr extract contained less impurities with higher relative content of rutin(70.9%)than that in methanolic extract(67.7%).This could be a milestone in extraction work for an efficient purification.展开更多
文摘Graphene edges with a zigzag-type atomic structure can theoretically produce spontaneous spin polarization despite being a critical-metal-free material. We have demonstrated this in graphene nanomeshes (GNMs) with honeycomb-like arrays of low-defect hexagonal nanopores by observing room-temperature ferromagnetism and spin-based phenomena arising from the zigzag-pore edges. Here, we apply extremely high electric fields to the ferromagnetic (FM) GNMs using an ionic-liquid gate. A large on/off-ratio for hole current is observed for even small applied ionic-liquid gate voltages (Vig). Observations of the magnetoresistance behavior reveal high carrier densities of ~1013 cm-2 at large Vig values. We find a maximum conductance peak in the high -Vig region and its separation into two peaks upon applying a side-gate (in-plane external) voltage (Vex). It is discussed that localized edge-π band with excess-density electrons induced by Vig and its spin splitting for majority and minority of spins by Vex (half-metallicity model) lead to these phenomena. The results must realize critical-element-free novel spintronic devices.
基金supported through the Annual Funding track by the Deanship of Scientific Research,Vice Presidency for Graduate Studies and Scientific Research,King Faisal University,Saudi Arabia[GRANT-415]。
文摘Five new tetrasubstituted imidazoles were designed with outstanding yields(83%-92%)in the occurrence of ionic liquid-based-pyridinium as a catalyst.The constructions of all synthesized derivatives were established by spectral tools and their purities were verified using thin-layer chromatography(TLC),displaying single-spot.The performance of corrosion protection of the prepared imidazole derivatives was examined theoretically and practically for acid steel corrosion.The experimental study was conducted by electrochemical(electrochemical impedance spectroscopy(EIS)and Tafel polarization(PPS))tools.The findings from the used approaches concluded that the synthesized compounds were wellorganized inhibitors with an efficiency of 90.7%-98.5%at 50℃and 0.7 mmol·L^(-1).The Tafel polarization results indicate the protective action of the additives was under mixed-monitoring.The additive adsorption on the electrode interface performed as a distinguished aspect for protection.The surface exploration on the blank and protected metal was completed by field emission scanning electron microscopy(FESEM).Computational studies by Monte Carlo(MC)simulation and quantum chemical calculation(DFT)were related to practical findings.The corrosion protection adsorption mechanism was reinforced by the preferable fitted Langmuir isotherm model.All findings from the applied-inspected approaches alternately confirm each other.
文摘In this present paper, the result of C6-C12 α-olefins oligomerizaton in the presence of recyclable chloroaluminate type ionic-liquid catalysts and their combination with Ti-containing complexes is presented. By different methods of analysis the composition and structure of oligoalkylnaphtenic products obtained in the presence of ionic-liquid catalysts and Ti-containing modifiers have been studied.
基金We acknowledge the financial supports from National Key R&D Program of China(Contract No.2017YFD0400901)Jiangsu Province(China)Agricultural Project(Contract No.BE2018329)+1 种基金Jiangsu Province Key Laboratory Project of Advanced Food Manufacturing Equipment and Technology(No.FMZ202003)National First-Class Discipline Program of Food Science and Technology(No.JUFSTR 20180205),all of which had enabled us to carry out this study.
文摘Asparagus(Asparagus officinalis)is a high-value low-calorie vegetable with array of bioactive compounds.Asparagus processing nevertheless generates substantial quantity of by-products;their valorization is of utmost importance for the sustainability of the industry.Here,feasibility of using four imidazolium-based ionic liquids and their combinations as well as water and methanol to extract bioactive compounds from asparagus leafy by-product was investigated.Effectiveness of ultrasound-microwave-assisted heating to augment extraction was also assessed.1-ethyl-3-methylimidazolium-bromide(EMIMBr)resulted in the highest extraction yield of rutin(25.7 mg/g),which is the most abundant compound in the by-product;such a yield was comparable to that achievable via methanol extraction.Ultrasound-microwave-assisted extraction did not show significant improvement in rutin yield when EMIMBr was used.Interestingly,although methanolic extract exhibited slightly higher content of rutin,it also contained the higher number of impurities;EMIMBr extract contained less impurities with higher relative content of rutin(70.9%)than that in methanolic extract(67.7%).This could be a milestone in extraction work for an efficient purification.
