Pub Date : 2024-11-05DOI: 10.1016/j.matchemphys.2024.130128
Nandini Robin Nadar , J. Deepak , S.C. Sharma , B.R. Radha Krushna , H. Nagabhushana , Augustine George , Pushparaj Samantsinghar , A. Banu , D.G. Anand
This study successfully synthesized pristine RGO-Gd2O3:Eu3+ nanocomposites (NCs) using a hydrothermal method, as confirmed by X-ray diffraction and TEM analysis. Cyclic voltammetry (CV) demonstrated that RGO-Gd2O3:Eu3+ NCs exhibited a superior specific capacitance (Csp) of 340 Fg⁻1 at a scan rate of 2 mV s⁻1. Impressively, the synthesized nanocomposites displayed high energy and power densities of 41 Wh/kg and 30000 W/kg, respectively, along with excellent capacity retention (91.12 %) and Coulombic efficiency (95.77 %). Modified glassy carbon electrodes (MGCEs) fabricated using these NCs showed promising electrochemical responses for dopamine (DA) detection at pH∼7. These findings highlight the potential of the developed electrode for both supercapacitor applications and DA sensing.
{"title":"Multifunctional RGO-Gd2O3:Eu3+ nanocomposites for supercapacitor and biosensor application","authors":"Nandini Robin Nadar , J. Deepak , S.C. Sharma , B.R. Radha Krushna , H. Nagabhushana , Augustine George , Pushparaj Samantsinghar , A. Banu , D.G. Anand","doi":"10.1016/j.matchemphys.2024.130128","DOIUrl":"10.1016/j.matchemphys.2024.130128","url":null,"abstract":"<div><div>This study successfully synthesized pristine RGO-Gd<sub>2</sub>O<sub>3</sub>:Eu<sup>3+</sup> nanocomposites (NCs) using a hydrothermal method, as confirmed by X-ray diffraction and TEM analysis. Cyclic voltammetry (CV) demonstrated that RGO-Gd<sub>2</sub>O<sub>3</sub>:Eu<sup>3+</sup> NCs exhibited a superior specific capacitance (Csp) of 340 Fg⁻<sup>1</sup> at a scan rate of 2 mV s⁻<sup>1</sup>. Impressively, the synthesized nanocomposites displayed high energy and power densities of 41 Wh/kg and 30000 W/kg, respectively, along with excellent capacity retention (91.12 %) and Coulombic efficiency (95.77 %). Modified glassy carbon electrodes (MGCEs) fabricated using these NCs showed promising electrochemical responses for dopamine (DA) detection at pH∼7. These findings highlight the potential of the developed electrode for both supercapacitor applications and DA sensing.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"329 ","pages":"Article 130128"},"PeriodicalIF":4.3,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142663548","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-03DOI: 10.1016/j.matchemphys.2024.130123
Shuaiqian Li, Zhaowen Du, Zhuoyue Wen
To investigate the corrosion resistance and failure process of various metal bolts within acidic environment. The comparative corrosion experiment was conducted on ordinary, zinc-immersed, and zinc-infiltrated bolts. The corrosion behavior and mechanism were analyzed in these three types of bolts. The results showed that within an acidic milieu, the corrosion resistance of ordinary bolt is notably inferior, succeeded by zinc-immersed bolts, and the zenith of corrosion resistance is observed in zinc-infiltrated bolts. The instantaneous corrosion rate constants for these bolts are found to be 0.25026, −0.19605, and −0.06209, respectively. After 100 days of corrosion, the degradation in mechanical properties for the three bolts manifested as the yield strength decreased by 6.50 %, 4.63 %, and 2.85 %, respectively, and the tensile strength decreased by 6.37 %, 3.99 %, and 1.45 %, respectively, and the elongation decreased by 15.85 %, 12.20 %, and 7.97 %, respectively. As the corrosion advanced, the tensile fracture behavior of ordinary bolt transitions from ductile fracture to ductile-brittle hybrid fracture, the tensile fracture behavior of zinc-immersed and zinc-infiltrated bolts remains ductile fracture. The corrosion process for the ordinary bolt follows dissolution-destruction mechanism, the zinc-immersed bolt follows dissolution-destruction-penetration mechanism, and the zinc-infiltrated bolt follows dissolution-transformation mechanism.
{"title":"Experimental study on corrosion behavior and failure mechanism of bolts in acidic environment","authors":"Shuaiqian Li, Zhaowen Du, Zhuoyue Wen","doi":"10.1016/j.matchemphys.2024.130123","DOIUrl":"10.1016/j.matchemphys.2024.130123","url":null,"abstract":"<div><div>To investigate the corrosion resistance and failure process of various metal bolts within acidic environment. The comparative corrosion experiment was conducted on ordinary, zinc-immersed, and zinc-infiltrated bolts. The corrosion behavior and mechanism were analyzed in these three types of bolts. The results showed that within an acidic milieu, the corrosion resistance of ordinary bolt is notably inferior, succeeded by zinc-immersed bolts, and the zenith of corrosion resistance is observed in zinc-infiltrated bolts. The instantaneous corrosion rate constants for these bolts are found to be 0.25026, −0.19605, and −0.06209, respectively. After 100 days of corrosion, the degradation in mechanical properties for the three bolts manifested as the yield strength decreased by 6.50 %, 4.63 %, and 2.85 %, respectively, and the tensile strength decreased by 6.37 %, 3.99 %, and 1.45 %, respectively, and the elongation decreased by 15.85 %, 12.20 %, and 7.97 %, respectively. As the corrosion advanced, the tensile fracture behavior of ordinary bolt transitions from ductile fracture to ductile-brittle hybrid fracture, the tensile fracture behavior of zinc-immersed and zinc-infiltrated bolts remains ductile fracture. The corrosion process for the ordinary bolt follows dissolution-destruction mechanism, the zinc-immersed bolt follows dissolution-destruction-penetration mechanism, and the zinc-infiltrated bolt follows dissolution-transformation mechanism.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"329 ","pages":"Article 130123"},"PeriodicalIF":4.3,"publicationDate":"2024-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142586224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-02DOI: 10.1016/j.matchemphys.2024.130119
Fujia Ben , Dan Xu , Xinyuan Zhou , Taolin Yu , Jiale Wei , Wenjie Zhao
Based on the synergistic roles of defect dipoles and MnO2 sintering aid, 0.8BaTiO3-0.2BiScO3 (BTBS0.2) ceramics with and without 0.3 wt% MnO2 were prepared by a solid-phase reaction route. The impacts of MnO2 dopant and sintering conditions on the crystalline structure, micro-morphology, dielectric, and energy storage properties were investigated in detail. The X-ray diffraction (XRD) and Raman results demonstrate the coexistence of tetragonal (T) and pseudo-cubic (pC) phases. The increased pC phase content caused by MnO2 modification is beneficial for the improvement of the relaxation degree. The O 1s fine spectra of X-ray photoelectron spectroscopy (XPS) confirms a remarkable increase in the concentration of oxygen vacancy due to the acceptor Mn dopant, indicating the valence changes of Mn ions from Mn4+ to Mn3+/Mn2+. The reduced dielectric loss is induced by the improved density and the pinning effect from the defect dipoles, thereby yielding a higher Eb. An optimal energy density of Wrec = 0.70 J/cm3 with a high energy efficiency of η = 95.8 % at 140 kV/cm was realized in the BTBS0.2+Mn ceramic composition sintered at 1300 °C. Moreover, the ceramic also exhibits good temperature stability (30–120 °C). Therefore, the BTBS0.2+Mn ceramics have a promising application prospect in the energy storage field.
{"title":"Crystalline structure and dielectric relaxor behavior of MnO2-modified 0.8BaTiO3-0.2BiScO3 ceramics for energy storage application","authors":"Fujia Ben , Dan Xu , Xinyuan Zhou , Taolin Yu , Jiale Wei , Wenjie Zhao","doi":"10.1016/j.matchemphys.2024.130119","DOIUrl":"10.1016/j.matchemphys.2024.130119","url":null,"abstract":"<div><div>Based on the synergistic roles of defect dipoles and MnO<sub>2</sub> sintering aid, 0.8BaTiO<sub>3</sub>-0.2BiScO<sub>3</sub> (BTBS<sub>0.2</sub>) ceramics with and without 0.3 wt% MnO<sub>2</sub> were prepared by a solid-phase reaction route. The impacts of MnO<sub>2</sub> dopant and sintering conditions on the crystalline structure, micro-morphology, dielectric, and energy storage properties were investigated in detail. The X-ray diffraction (XRD) and Raman results demonstrate the coexistence of tetragonal (T) and pseudo-cubic (pC) phases. The increased pC phase content caused by MnO<sub>2</sub> modification is beneficial for the improvement of the relaxation degree. The O 1s fine spectra of X-ray photoelectron spectroscopy (XPS) confirms a remarkable increase in the concentration of oxygen vacancy due to the acceptor Mn dopant, indicating the valence changes of Mn ions from Mn<sup>4+</sup> to Mn<sup>3+</sup>/Mn<sup>2+</sup>. The reduced dielectric loss is induced by the improved density and the pinning effect from the defect dipoles, thereby yielding a higher <em>E</em><sub>b</sub>. An optimal energy density of <em>W</em><sub>rec</sub> = 0.70 J/cm<sup>3</sup> with a high energy efficiency of <em>η</em> = 95.8 % at 140 kV/cm was realized in the BTBS<sub>0.2</sub>+Mn ceramic composition sintered at 1300 °C. Moreover, the ceramic also exhibits good temperature stability (30–120 °C). Therefore, the BTBS<sub>0.2</sub>+Mn ceramics have a promising application prospect in the energy storage field.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"329 ","pages":"Article 130119"},"PeriodicalIF":4.3,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142571471","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-02DOI: 10.1016/j.matchemphys.2024.130109
I.Z. Al-Yahmadi, A. Gismelseed, H.M. Widatallah, F. Bzour, F. Al Ma'Mari, A. Al-Rawas, M. ElZain
The influence of Gd3+ doping on the magnetocaloric properties of Nd0.6-xGdxSr0.4MnO3 (0.02 ≤ x ≤ 0.1) compounds, prepared using auto-combustion sol-gel technique, has been studied. Rietveld refinement of the X-ray diffraction (XRD) data has shown all compounds to be nanocrystalline with single-phased orthorhombic structures that index to the Pnma space group. The unit cell volumes reduce as the Gd3+ ions gradually substitute the Nd3+ones. The tuning Mn4+/Mn3+ ratio for all compounds, which are slightly lower than that of the Gd-free compound, demonstrates almost equal amounts of both ions. A ferromagnetic-to-paramagnetic transition is observed with rising temperature wherein the Curie temperature (TC) gradually drops with increasing Gd3+ concentration (x). All materials exhibit ferromagnetism at 2 K, with saturation magnetization values that increase slightly with x. Both the calculated maximum magnetic entropies () and relative cooling powers (RCP) increase to relatively large values with increasing temperature and x values. The values obtained for and RCP for Nd0.6-xGdxSr0.4MnO3 (0.02 ≤ x ≤ 0.1) are comparable with those of standard pure Gd revealing their potential as magnetic refrigeration systems.
研究人员利用自燃烧溶胶-凝胶技术制备了 Nd0.6-xGdxSr0.4MnO3 (0.02 ≤ x ≤ 0.1) 化合物，研究了掺杂 Gd3+ 对其磁致性的影响。对 X 射线衍射（XRD）数据进行的里特维尔德细化表明，所有化合物都是纳米晶体，具有单相正交菱形结构，属于 Pnma 空间群。随着 Gd3+ 离子逐渐取代 Nd3+ 离子，单胞体积减小。所有化合物的 Mn4+/Mn3+ 比率都略低于无 Gd 的化合物，这表明这两种离子的含量几乎相等。随着温度的升高，可观察到铁磁性向顺磁性的转变，居里温度（TC）随着 Gd3+ 浓度（x）的增加而逐渐降低。随着温度和 x 值的增加，计算得出的最大磁熵（|ΔSMMax|）和相对冷却功率（RCP）都会增加到相对较大的值。Nd0.6-xGdxSr0.4MnO3（0.02 ≤ x ≤ 0.1）的|ΔSMMax|和 RCP 值与标准纯 Gd 的值相当，这揭示了它们作为磁制冷系统的潜力。
{"title":"Enhancement of the magnetocaloric effect in Nd0.6-xGdxSr0.4MnO3 (0.02 ≤ x ≤ 0.1) perovskite manganites: The role of Gd3+ ionic substitution","authors":"I.Z. Al-Yahmadi, A. Gismelseed, H.M. Widatallah, F. Bzour, F. Al Ma'Mari, A. Al-Rawas, M. ElZain","doi":"10.1016/j.matchemphys.2024.130109","DOIUrl":"10.1016/j.matchemphys.2024.130109","url":null,"abstract":"<div><div>The influence of Gd<sup>3+</sup> doping on the magnetocaloric properties of Nd<sub>0.6-<em>x</em></sub>Gd<sub><em>x</em></sub>Sr<sub>0.4</sub>MnO<sub>3</sub> (0.02 ≤ <em>x</em> ≤ 0.1) compounds, prepared using auto-combustion sol-gel technique, has been studied. Rietveld refinement of the X-ray diffraction (XRD) data has shown all compounds to be nanocrystalline with single-phased orthorhombic structures that index to the <em>Pnma</em> space group. The unit cell volumes reduce as the Gd<sup>3+</sup> ions gradually substitute the Nd<sup>3+</sup>ones. The tuning Mn<sup>4+</sup>/Mn<sup>3+</sup> ratio for all compounds, which are slightly lower than that of the Gd-free compound, demonstrates almost equal amounts of both ions. A ferromagnetic-to-paramagnetic transition is observed with rising temperature wherein the Curie temperature (T<sub>C</sub>) gradually drops with increasing Gd<sup>3+</sup> concentration (<em>x</em>). All materials exhibit ferromagnetism at 2 K, with saturation magnetization values that increase slightly with <em>x</em>. Both the calculated maximum magnetic entropies (<span><math><mrow><mo>|</mo><mrow><mo>Δ</mo><msubsup><mi>S</mi><mi>M</mi><mi>Max</mi></msubsup></mrow><mo>|</mo></mrow></math></span>) and relative cooling powers (RCP) increase to relatively large values with increasing temperature and <em>x</em> values. The values obtained for <span><math><mrow><mo>|</mo><mrow><mo>Δ</mo><msubsup><mi>S</mi><mi>M</mi><mi>Max</mi></msubsup></mrow><mo>|</mo></mrow></math></span> and RCP for Nd<sub>0.6-<em>x</em></sub>Gd<sub><em>x</em></sub>Sr<sub>0.4</sub>MnO<sub>3</sub> (0.02 ≤ <em>x</em> ≤ 0.1) are comparable with those of standard pure Gd revealing their potential as magnetic refrigeration systems.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"329 ","pages":"Article 130109"},"PeriodicalIF":4.3,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142663455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-02DOI: 10.1016/j.matchemphys.2024.130108
Neha Patni, Shibu G. Pillai
The photovoltaic study of the fabricated dye sensitized solar cells is revealed in this paper. To provide indium free approach, fluorine doped tin oxide (FTO) and aluminium doped zinc oxide (AZO) glass substrate were used as charge collectors for counter electrodes and photoanode respectively. Also, a novel and natural mixed dye was used as sensitizer and mixture of doped polymer (polyaniline with metallic oxides of tin, vanadium and cerium) and iodide-triiodide couple was utilized as electrolyte for the cell. Optical band gap and light absorption performance of dyes were studied by ultraviolet–visible (UV–vis) spectroscopy. Surface morphology and elemental composition of polymer composites was studied using scanning electron microscopic (SEM) with energy dispersive X ray (EDX) analysis. Phase analysis of the composites was determined by X-ray diffraction and thermal behavior with the help of thermogravimetric analysis (TGA). Photovoltaic characteristics (I–V) and induced photon to current efficiency (IPCE) measurements were also investigated. Highest IPCE of 17.7 % was observed when polyaniline was doped with oxide of vanadium. Hence an efficient, green, indium free and novel cell is fabricated by the usage of different charge collector substrate, natural dye sensitizer and quasi solid-state electrolyte.
本文对所制造的染料敏化太阳能电池进行了光伏研究。为了提供无铟方法，掺氟氧化锡（FTO）和掺铝氧化锌（AZO）玻璃基板分别用作反电极和光阳极的电荷收集器。此外，一种新型天然混合染料被用作敏化剂，掺杂聚合物（含有锡、钒和铈金属氧化物的聚苯胺）和碘-三碘化物对的混合物被用作电池的电解质。通过紫外-可见（UV-vis）光谱研究了染料的光带隙和光吸收性能。利用扫描电子显微镜（SEM）和能量色散 X 射线（EDX）分析法研究了聚合物复合材料的表面形态和元素组成。通过 X 射线衍射和热重分析（TGA）确定了复合材料的相分析和热行为。此外，还对光伏特性（I-V）和诱导光子电流效率（IPCE）进行了测量。当聚苯胺掺杂氧化钒时，IPCE 最高，达到 17.7%。因此，通过使用不同的电荷收集基底、天然染料敏化剂和准固态电解质，制造出了一种高效、绿色、无铟的新型电池。
{"title":"Improvement in the performance of indium free dye sensitized solar cell by the use of polyaniline composite","authors":"Neha Patni, Shibu G. Pillai","doi":"10.1016/j.matchemphys.2024.130108","DOIUrl":"10.1016/j.matchemphys.2024.130108","url":null,"abstract":"<div><div>The photovoltaic study of the fabricated dye sensitized solar cells is revealed in this paper. To provide indium free approach, fluorine doped tin oxide (FTO) and aluminium doped zinc oxide (AZO) glass substrate were used as charge collectors for counter electrodes and photoanode respectively. Also, a novel and natural mixed dye was used as sensitizer and mixture of doped polymer (polyaniline with metallic oxides of tin, vanadium and cerium) and iodide-triiodide couple was utilized as electrolyte for the cell. Optical band gap and light absorption performance of dyes were studied by ultraviolet–visible (UV–vis) spectroscopy. Surface morphology and elemental composition of polymer composites was studied using scanning electron microscopic (SEM) with energy dispersive X ray (EDX) analysis. Phase analysis of the composites was determined by X-ray diffraction and thermal behavior with the help of thermogravimetric analysis (TGA). Photovoltaic characteristics (I–V) and induced photon to current efficiency (IPCE) measurements were also investigated. Highest IPCE of 17.7 % was observed when polyaniline was doped with oxide of vanadium. Hence an efficient, green, indium free and novel cell is fabricated by the usage of different charge collector substrate, natural dye sensitizer and quasi solid-state electrolyte.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"329 ","pages":"Article 130108"},"PeriodicalIF":4.3,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142663492","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-02DOI: 10.1016/j.matchemphys.2024.130092
Xiangfen Li , Yelong Tong , Zhongyi Yin , Hui Jia , Xi Yan , Xiaoyue Guo , Shiwen Lei , Long Gao , Jinxing Liu , Zechao Tao , Zhanjun Liu
The present work tries to explore the evolution process of electro-magnetic interference shielding effectiveness and thermal conductivity of graphene film. There is an obvious promotion of electrical conductivity (from 3.51 × 10−3 to 769.20 S m−1) when GO is thermally reduced at 1100 °C. Correspondingly, the reduced graphene oxide (rGO) achieves the highest EMI shielding effectiveness (∼54.84 dB) at 1100 °C which is a synergetic result of electrical conductivity and porous structure with rich defects. The rGO is furtherly graphitized at 2800 °C (G-rGO) to repair the defects and C–C network and then mechanically rolled to a densified film with bulk density of 1.64 g cm−3 (called as DG-rGO). The thermal conductivity of DG-rGO membrane increases to 720.56 W m−1 K−1 after graphitization and rolling. Porous structure and defects are beneficial to higher EMI shielding effectiveness while dense structure without defects lead to higher thermal conductivity. Therefore, the highest EMI shielding effectiveness and thermal conductivity cannot be obtained simultaneously. A reference range is provided to fulfill the request of EMI shielding and thermal conductivity.
本研究试图探索石墨烯薄膜的电磁干扰屏蔽效果和热导率的演变过程。在 1100 °C 下对 GO 进行热还原时，导电率明显提高（从 3.51 × 10-3 提高到 769.20 S m-1）。相应地，还原氧化石墨烯（rGO）在 1100 ℃ 时达到了最高的电磁干扰屏蔽效果（54.84 dB），这是导电性和富含缺陷的多孔结构协同作用的结果。rGO 在 2800 ℃ 时进一步石墨化（G-rGO）以修复缺陷和 C-C 网络，然后机械轧制成体积密度为 1.64 g cm-3 的致密薄膜（称为 DG-rGO）。经过石墨化和滚压后，DG-rGO 膜的热导率增加到 720.56 W m-1 K-1。多孔结构和缺陷有利于提高 EMI 屏蔽效果，而无缺陷的致密结构则会导致更高的热导率。因此，不可能同时获得最高的 EMI 屏蔽效果和热导率。为满足 EMI 屏蔽和热导率的要求，我们提供了一个参考范围。
{"title":"Revealing synergistic relationship of thermal conduction and electromagnetic shielding of reduced graphene oxide film","authors":"Xiangfen Li , Yelong Tong , Zhongyi Yin , Hui Jia , Xi Yan , Xiaoyue Guo , Shiwen Lei , Long Gao , Jinxing Liu , Zechao Tao , Zhanjun Liu","doi":"10.1016/j.matchemphys.2024.130092","DOIUrl":"10.1016/j.matchemphys.2024.130092","url":null,"abstract":"<div><div>The present work tries to explore the evolution process of electro-magnetic interference shielding effectiveness and thermal conductivity of graphene film. There is an obvious promotion of electrical conductivity (from 3.51 × 10<sup>−3</sup> to 769.20 S m<sup>−1</sup>) when GO is thermally reduced at 1100 °C. Correspondingly, the reduced graphene oxide (rGO) achieves the highest EMI shielding effectiveness (∼54.84 dB) at 1100 °C which is a synergetic result of electrical conductivity and porous structure with rich defects. The rGO is furtherly graphitized at 2800 °C (G-rGO) to repair the defects and C–C network and then mechanically rolled to a densified film with bulk density of 1.64 g cm<sup>−3</sup> (called as DG-rGO). The thermal conductivity of DG-rGO membrane increases to 720.56 W m<sup>−1</sup> K<sup>−1</sup> after graphitization and rolling. Porous structure and defects are beneficial to higher EMI shielding effectiveness while dense structure without defects lead to higher thermal conductivity. Therefore, the highest EMI shielding effectiveness and thermal conductivity cannot be obtained simultaneously. A reference range is provided to fulfill the request of EMI shielding and thermal conductivity.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"329 ","pages":"Article 130092"},"PeriodicalIF":4.3,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142663457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-02DOI: 10.1016/j.matchemphys.2024.130105
Omar R. Soliman , Ahmed F. Mabied , Saber A. Ibrahim , Ahmad M. Labeeb
Several simple methods were performed to recycle compact discs (CDs) using an alkaline solution. The hydrophilic silica nanoparticles were incorporated into the recycled deinked polycarbonate CDs, and these particles affected the dielectric, structure, and thermal properties of the recycled polycarbonates. The thermal properties of recycled CDs were studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). No significant change in the thermal stability of polycarbonate/silica nanocomposites was observed with the mechanical/chemical modifications. X-ray diffraction (XRD) revealed the structural aspects, showing a correlation between crystallinity, silica nanoparticles, and modification methods. The mechanically treated sample after chemical handling had the lowest degree of crystallinity (48 %), showing that the modification methods enhanced the formation of the amorphous state, thus affecting its dielectric properties. Scanning electron microscopy (SEM) characterized the CD samples' microstructure and morphology. Finally, the dielectric properties were studied using broadband dielectric spectroscopy (BDS) in the 101–106 Hz range. The samples prepared using chemical and mechanical treatments were of low dielectric loss. This increases its importance when such samples are used as antistatic charge materials. For these reasons, recycled PC/SiO2 nanocomposites are recommended as effective packaging materials for electronic components.
{"title":"Nanosilica/recycled polycarbonate composites for electronic packaging","authors":"Omar R. Soliman , Ahmed F. Mabied , Saber A. Ibrahim , Ahmad M. Labeeb","doi":"10.1016/j.matchemphys.2024.130105","DOIUrl":"10.1016/j.matchemphys.2024.130105","url":null,"abstract":"<div><div>Several simple methods were performed to recycle compact discs (CDs) using an alkaline solution. The hydrophilic silica nanoparticles were incorporated into the recycled deinked polycarbonate CDs, and these particles affected the dielectric, structure, and thermal properties of the recycled polycarbonates. The thermal properties of recycled CDs were studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). No significant change in the thermal stability of polycarbonate/silica nanocomposites was observed with the mechanical/chemical modifications. X-ray diffraction (XRD) revealed the structural aspects, showing a correlation between crystallinity, silica nanoparticles, and modification methods. The mechanically treated sample after chemical handling had the lowest degree of crystallinity (48 %), showing that the modification methods enhanced the formation of the amorphous state, thus affecting its dielectric properties. Scanning electron microscopy (SEM) characterized the CD samples' microstructure and morphology. Finally, the dielectric properties were studied using broadband dielectric spectroscopy (BDS) in the 10<sup>1</sup>–10<sup>6</sup> Hz range. The samples prepared using chemical and mechanical treatments were of low dielectric loss. This increases its importance when such samples are used as antistatic charge materials. For these reasons, recycled PC/SiO<sub>2</sub> nanocomposites are recommended as effective packaging materials for electronic components.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"329 ","pages":"Article 130105"},"PeriodicalIF":4.3,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142663448","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-02DOI: 10.1016/j.matchemphys.2024.130094
Fatma Chergui , Adel Mokhtar , Soumia Abdelkrim , Amina Sardi , Mohammed Hachemaoui , Bouhadjar Boukoussa , Amal Djelad , Mohammed Sassi , Gianluca Viscusi , Mohamed Abboud
This article presents a sustainable method for the catalytic reduction of both simple and binary dye systems using magnetic activated carbon (Fe3O4@AC) synthesized from almond shells, an agricultural waste biomass. The reduction of methylene blue (MB) and Congo red (CR) was investigated in the presence of NaBH4, and a series of physical-chemical experiments were conducted to elucidate the mechanism of dye conversion and its performance. The results confirmed the successful synthesis of Fe3O4 nanoparticles on the activated carbon surface. The calculated rate constants in a simple system were 0.34 min⁻1 for MB and 0.25 min⁻1 for CR, in the binary system, the Fe3O4@AC catalyst demonstrated enhanced selectivity for the cationic MB dye, attributable to the robust, attractive surface charge. The study aimed to enhance catalytic performance by employing optimization curves generated from a three-level Box-Behnken Design (BBD) simulation. Experimental results indicated that the optimal catalyst dose, dye concentration, and reaction duration were 4–7 mg, 80–120 mg/L, and 5–20 min, respectively. Response surface methodology (RSM) was developed by processing the findings from 17 replicated experiments using a two-quadratic polynomial model, establishing a functional link between the experimental parameters and MB conversion. Optimal conditions for MB conversion were determined to be 7 mg of catalyst, 80 mg/L of MB concentration, and a reaction time of 12.5 minutes, resulting in an estimated conversion rate of 99.99 %. This prediction was validated by experimental findings, with regression analysis confirming a high correlation (R2 > 0.99) between the predicted and observed values. Additionally, the Fe3O4@AC catalyst demonstrated good recyclability and stable performance over three consecutive cycles, maintaining high conversion efficiency without loss of performance. These findings demonstrate that Fe3O4@AC is a viable approach for the rapid and efficient remediation of dyes in water.
{"title":"Optimizing catalytic performance: Reduction of organic dyes using synthesized Fe3O4@AC magnetic nano-catalyst","authors":"Fatma Chergui , Adel Mokhtar , Soumia Abdelkrim , Amina Sardi , Mohammed Hachemaoui , Bouhadjar Boukoussa , Amal Djelad , Mohammed Sassi , Gianluca Viscusi , Mohamed Abboud","doi":"10.1016/j.matchemphys.2024.130094","DOIUrl":"10.1016/j.matchemphys.2024.130094","url":null,"abstract":"<div><div>This article presents a sustainable method for the catalytic reduction of both simple and binary dye systems using magnetic activated carbon (Fe<sub>3</sub>O<sub>4</sub>@AC) synthesized from almond shells, an agricultural waste biomass. The reduction of methylene blue (MB) and Congo red (CR) was investigated in the presence of NaBH<sub>4</sub>, and a series of physical-chemical experiments were conducted to elucidate the mechanism of dye conversion and its performance. The results confirmed the successful synthesis of Fe<sub>3</sub>O<sub>4</sub> nanoparticles on the activated carbon surface. The calculated rate constants in a simple system were 0.34 min⁻<sup>1</sup> for MB and 0.25 min⁻<sup>1</sup> for CR, in the binary system, the Fe<sub>3</sub>O<sub>4</sub>@AC catalyst demonstrated enhanced selectivity for the cationic MB dye, attributable to the robust, attractive surface charge. The study aimed to enhance catalytic performance by employing optimization curves generated from a three-level Box-Behnken Design (BBD) simulation. Experimental results indicated that the optimal catalyst dose, dye concentration, and reaction duration were 4–7 mg, 80–120 mg/L, and 5–20 min, respectively. Response surface methodology (RSM) was developed by processing the findings from 17 replicated experiments using a two-quadratic polynomial model, establishing a functional link between the experimental parameters and MB conversion. Optimal conditions for MB conversion were determined to be 7 mg of catalyst, 80 mg/L of MB concentration, and a reaction time of 12.5 minutes, resulting in an estimated conversion rate of 99.99 %. This prediction was validated by experimental findings, with regression analysis confirming a high correlation (R<sup>2</sup> > 0.99) between the predicted and observed values. Additionally, the Fe<sub>3</sub>O<sub>4</sub>@AC catalyst demonstrated good recyclability and stable performance over three consecutive cycles, maintaining high conversion efficiency without loss of performance. These findings demonstrate that Fe<sub>3</sub>O<sub>4</sub>@AC is a viable approach for the rapid and efficient remediation of dyes in water.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"329 ","pages":"Article 130094"},"PeriodicalIF":4.3,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142663494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-02DOI: 10.1016/j.matchemphys.2024.130122
D.T. Yu , R. Wang , C.L. Wu , Z.Z. Wang , S. Zhang , C.H. Zhang , H.T. Chen , X.P. Tao
FeCrNiMnAl high entropy alloy (HEA) coatings are prepared on the surface of 304 stainless steel (304 SS) by laser cladding. The effects of laser energy density on the residual stress, microstructure, nanoindentation behavior, the resistance to wear, corrosion and cavitation erosion (CE) of FeCrNiMnAl HEA coatings are studied. Experimental results shows that when the laser energy density decreases from 40 J/mm2 to 24 J/mm2, the phase composition of the FeCrNiMnAl HEA coatings remains unchanged with a single BCC solid solution and the elements are uniformly distributed without obvious segregation. The average grain size of the HEA coatings is refined from 73.5 to 41.7 μm. When the laser energy density is 28 J/mm2 for S3 sample, the coating displays good forming quality and excellent comprehensive performance. The specific wear rate is only 8.2 % that of the 304 SS substrate. In addition, S3 exhibits the highest corrosion resistance as indicated by the highest corrosion potential (Ecorr) and the lowest corrosion current density (Icorr) in 3.5 wt% NaCl solution. After 10-h CE, the mean depth erosion rate (MDER) of S3 is the lowest (1.69 ± 0.03 μm/h), which is much lower than that of 304 SS (4.96 ± 0.13 μm/h), and the pure mechanical damage plays a dominant role in CE, followed by the synergistic damage effect. The excellent CE resistance of S3 is attributed to its excellent combination of corrosion resistance, mechanical properties and the self-recovery ability of passivation film.
通过激光熔覆在 304 不锈钢（304 SS）表面制备了铁铬镍锰铝高熵合金（HEA）涂层。研究了激光能量密度对铁铬镍锰铝高熵合金涂层的残余应力、微观结构、纳米压痕行为、抗磨损性、抗腐蚀性和气蚀性（CE）的影响。实验结果表明，当激光能量密度从 40 J/mm2 降低到 24 J/mm2 时，FeCrNiMnAl HEA 涂层的相组成保持不变，为单一 BCC 固溶体，元素分布均匀，无明显偏析。HEA 涂层的平均晶粒尺寸从 73.5 微米细化到 41.7 微米。当 S3 样品的激光能量密度为 28 J/mm2 时，涂层显示出良好的成型质量和优异的综合性能。比磨损率仅为 304 SS 基材的 8.2%。此外，在 3.5 wt% 的 NaCl 溶液中，S3 具有最高的腐蚀电位（Ecorr）和最低的腐蚀电流密度（Icorr），显示出最高的耐腐蚀性。10 h CE 后，S3 的平均深度侵蚀速率（MDER）最低（1.69 ± 0.03 μm/h），远低于 304 SS（4.96 ± 0.13 μm/h），纯机械损伤在 CE 中起主导作用，其次是协同损伤效应。S3 优异的抗 CE 性能得益于其出色的耐腐蚀性能、机械性能和钝化膜自恢复能力。
{"title":"Effects of laser energy density on the resistance to wear and cavitation erosion of FeCrNiMnAl high entropy alloy coatings by laser cladding","authors":"D.T. Yu , R. Wang , C.L. Wu , Z.Z. Wang , S. Zhang , C.H. Zhang , H.T. Chen , X.P. Tao","doi":"10.1016/j.matchemphys.2024.130122","DOIUrl":"10.1016/j.matchemphys.2024.130122","url":null,"abstract":"<div><div>FeCrNiMnAl high entropy alloy (HEA) coatings are prepared on the surface of 304 stainless steel (304 SS) by laser cladding. The effects of laser energy density on the residual stress, microstructure, nanoindentation behavior, the resistance to wear, corrosion and cavitation erosion (CE) of FeCrNiMnAl HEA coatings are studied. Experimental results shows that when the laser energy density decreases from 40 J/mm<sup>2</sup> to 24 J/mm<sup>2</sup>, the phase composition of the FeCrNiMnAl HEA coatings remains unchanged with a single BCC solid solution and the elements are uniformly distributed without obvious segregation. The average grain size of the HEA coatings is refined from 73.5 to 41.7 μm. When the laser energy density is 28 J/mm<sup>2</sup> for S3 sample, the coating displays good forming quality and excellent comprehensive performance. The specific wear rate is only 8.2 % that of the 304 SS substrate. In addition, S3 exhibits the highest corrosion resistance as indicated by the highest corrosion potential (<em>E</em><sub><em>corr</em></sub>) and the lowest corrosion current density (<em>I</em><sub><em>corr</em></sub>) in 3.5 wt% NaCl solution. After 10-h CE, the mean depth erosion rate (MDER) of S3 is the lowest (1.69 ± 0.03 μm/h), which is much lower than that of 304 SS (4.96 ± 0.13 μm/h), and the pure mechanical damage plays a dominant role in CE, followed by the synergistic damage effect. The excellent CE resistance of S3 is attributed to its excellent combination of corrosion resistance, mechanical properties and the self-recovery ability of passivation film.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"329 ","pages":"Article 130122"},"PeriodicalIF":4.3,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142586226","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-01DOI: 10.1016/j.matchemphys.2024.130114
M.A. Hussein , A. Madhan Kumar , M.A. Azeem , N. Ankah , S. Saravanan
This study presents a new biological high-entropy alloy (Bio-HEA) composed of 35Ti-35Zr-20Nb-5Ta-5Ag (at. %) for potential dental implant applications. The Bio-HEA underwent processing for various durations of mechanical alloying, followed by compaction and sintering. The processed Bio-HEA was tested for corrosion resistance in an artificial saliva medium, antibacterial properties, and surface characteristics. Surface topography and wettability were investigated using atomic force microscopy, surface profilometry, and contact angle measurements. Mechanical alloying, X-ray diffraction, and scanning electron microscopy revealed the formation of a solid-solution Bio-HEA with body-centered cubic crystal structures, with phase variations depending on the processing conditions. The Bio-HEA exhibited significantly higher microhardness values (4.38 GPa and 5.35 GPa) than commercial pure titanium (CPTi) and Ti-6Al-4V alloy, respectively. An increased ball-milling time resulted in higher microhardness for Bio-HEA and enhanced in vitro corrosion resistance in artificial saliva compared to CPTi. This was evidenced by a significant nobler shift of approximately 200 mV in the corrosion potential, with a prominent decrease of approximately two orders of magnitude in the corrosion current density and a higher charge transfer resistance. Additionally, the Bio-HEA demonstrated a lower contact angle compared to that of the Ti-6Al-4V alloy and CPTi. The Bio-HEA achieved antibacterial efficiencies of 91.76 % and 93.0 % compared to Ti-6Al-4V alloy and CPTi, respectively. The enhanced microhardness, antibacterial properties, in vitro corrosion resistance in artificial saliva, and wettability of Bio-HEA compared to commercial Ti-6Al-4V alloy and CPTi makes it a promising candidate for dental bioimplant applications.
{"title":"Development of Ti-Zr-Nb-Ta-Ag high entropy alloy for dental implants: In vitro corrosion behavior, antibacterial effect, and surface characteristics","authors":"M.A. Hussein , A. Madhan Kumar , M.A. Azeem , N. Ankah , S. Saravanan","doi":"10.1016/j.matchemphys.2024.130114","DOIUrl":"10.1016/j.matchemphys.2024.130114","url":null,"abstract":"<div><div>This study presents a new biological high-entropy alloy (Bio-HEA) composed of 35Ti-35Zr-20Nb-5Ta-5Ag (at. %) for potential dental implant applications. The Bio-HEA underwent processing for various durations of mechanical alloying, followed by compaction and sintering. The processed Bio-HEA was tested for corrosion resistance in an artificial saliva medium, antibacterial properties, and surface characteristics. Surface topography and wettability were investigated using atomic force microscopy, surface profilometry, and contact angle measurements. Mechanical alloying, X-ray diffraction, and scanning electron microscopy revealed the formation of a solid-solution Bio-HEA with body-centered cubic crystal structures, with phase variations depending on the processing conditions. The Bio-HEA exhibited significantly higher microhardness values (4.38 GPa and 5.35 GPa) than commercial pure titanium (CPTi) and Ti-6Al-4V alloy, respectively. An increased ball-milling time resulted in higher microhardness for Bio-HEA and enhanced in vitro corrosion resistance in artificial saliva compared to CPTi. This was evidenced by a significant nobler shift of approximately 200 mV in the corrosion potential, with a prominent decrease of approximately two orders of magnitude in the corrosion current density and a higher charge transfer resistance. Additionally, the Bio-HEA demonstrated a lower contact angle compared to that of the Ti-6Al-4V alloy and CPTi. The Bio-HEA achieved antibacterial efficiencies of 91.76 % and 93.0 % compared to Ti-6Al-4V alloy and CPTi, respectively. The enhanced microhardness, antibacterial properties, in vitro corrosion resistance in artificial saliva, and wettability of Bio-HEA compared to commercial Ti-6Al-4V alloy and CPTi makes it a promising candidate for dental bioimplant applications.</div></div>","PeriodicalId":18227,"journal":{"name":"Materials Chemistry and Physics","volume":"329 ","pages":"Article 130114"},"PeriodicalIF":4.3,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142594105","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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