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Samaddar S, Strasdas J, Janßen K, Just S, Johnsen T, Wang Z, Uzlu B, Li S, Neumaier D, Liebmann M, Morgenstern M. Evidence for Local Spots of Viscous Electron Flow in Graphene at Moderate Mobility. NANO LETTERS 2021; 21:9365-9373. [PMID: 34734723 DOI: 10.1021/acs.nanolett.1c01145] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Dominating electron-electron scattering enables viscous electron flow exhibiting hydrodynamic current density patterns, such as Poiseuille profiles or vortices. The viscous regime has recently been observed in graphene by nonlocal transport experiments and mapping of the Poiseuille profile. Herein, we probe the current-induced surface potential maps of graphene field-effect transistors with moderate mobility using scanning probe microscopy at room temperature. We discover micrometer-sized large areas appearing close to charge neutrality that show current-induced electric fields opposing the externally applied field. By estimating the local scattering lengths from the gate dependence of local in-plane electric fields, we find that electron-electron scattering dominates in these areas as expected for viscous flow. Moreover, we suppress the inverted fields by artificially decreasing the electron-disorder scattering length via mild ion bombardment. These results imply that viscous electron flow is omnipresent in graphene devices, even at moderate mobility.
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Affiliation(s)
- Sayanti Samaddar
- 2nd Institute of Physics B and JARA-FIT, RWTH Aachen University, Otto-Blumenthal-Straße, 52074 Aachen, Germany
- National Physical Laboratory, Hampton Road, Teddington TW11 0LW, United Kingdom
| | - Jeff Strasdas
- 2nd Institute of Physics B and JARA-FIT, RWTH Aachen University, Otto-Blumenthal-Straße, 52074 Aachen, Germany
| | - Kevin Janßen
- 2nd Institute of Physics B and JARA-FIT, RWTH Aachen University, Otto-Blumenthal-Straße, 52074 Aachen, Germany
- Peter Grünberg Institute 6 & 9, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Sven Just
- 2nd Institute of Physics B and JARA-FIT, RWTH Aachen University, Otto-Blumenthal-Straße, 52074 Aachen, Germany
- Leibniz Institute for Solid State and Materials Research Dresden (IFW), 01171 Dresden, Germany
| | - Tjorven Johnsen
- 2nd Institute of Physics B and JARA-FIT, RWTH Aachen University, Otto-Blumenthal-Straße, 52074 Aachen, Germany
| | - Zhenxing Wang
- Advanced Microelectronic Center Aachen (AMICA), AMO GmbH, Otto-Blumenthal-Str. 25, 52074 Aachen, Germany
| | - Burkay Uzlu
- Advanced Microelectronic Center Aachen (AMICA), AMO GmbH, Otto-Blumenthal-Str. 25, 52074 Aachen, Germany
- Chair of Electronic Devices, RWTH Aachen University, 52074 Aachen, Germany
| | - Sha Li
- Advanced Microelectronic Center Aachen (AMICA), AMO GmbH, Otto-Blumenthal-Str. 25, 52074 Aachen, Germany
| | - Daniel Neumaier
- Advanced Microelectronic Center Aachen (AMICA), AMO GmbH, Otto-Blumenthal-Str. 25, 52074 Aachen, Germany
- University of Wuppertal, 42285 Wuppertal, Germany
| | - Marcus Liebmann
- 2nd Institute of Physics B and JARA-FIT, RWTH Aachen University, Otto-Blumenthal-Straße, 52074 Aachen, Germany
| | - Markus Morgenstern
- 2nd Institute of Physics B and JARA-FIT, RWTH Aachen University, Otto-Blumenthal-Straße, 52074 Aachen, Germany
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Li J, Liu M, Qiu Y, Gan Y, Jiang H, Liu B, Wei H, Ma N. Urchin-like Hydroxyapatite/Graphene Hollow Microspheres as pH-Responsive Bone Drug Carriers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:4137-4146. [PMID: 33813823 DOI: 10.1021/acs.langmuir.0c03640] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Hydroxyapatite (HA) is the main inorganic component of human bones and teeth. It has good biocompatibility and bioactivity, which promotes its good application prospects in the field of bone drug carriers. In this study, tetraethylenepentamine-graphene (rGO-TEPA)/CaCO3:HA composite microspheres were prepared via microwave hydrothermal synthesis using rGO-TEPA/CaCO3 solid microspheres as intermediates. Furthermore, the incompletely transformed CaCO3 was removed by soaking in a citric acid buffer to obtain rGO-TEPA/HA hollow composite microspheres. The two types of as-prepared composite microspheres exhibited sea urchin-like structures, large BET surface areas, and good dispersibility. Mouse preosteoblast cells (MC3T3-E1) were used for in vitro cytotoxicity experiments. The in vitro cell viability test showed that the two composite drug carriers exhibited noncytotoxicity. Moreover, the doxorubicin (DOX) loading and releasing investigations revealed that the two types of prepared carriers had mild storage-release behaviors and good pH responsiveness. Hence, these rGO-TEPA/HA hollow microspheres have promising applications as bone drug carriers.
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Affiliation(s)
- Jie Li
- College of Light Industry Science and Engineering, Tianjin University of Science and Technology, 300222 Tianjin, China
| | - Miaomiao Liu
- College of Light Industry Science and Engineering, Tianjin University of Science and Technology, 300222 Tianjin, China
| | - Yujuan Qiu
- College of Light Industry Science and Engineering, Tianjin University of Science and Technology, 300222 Tianjin, China
| | - Yuanjing Gan
- College of Light Industry Science and Engineering, Tianjin University of Science and Technology, 300222 Tianjin, China
| | - Hongkun Jiang
- Key Laboratory of Superlight Material and Surface Technology of Ministry of Education, College of Material Science and Chemical Engineering, Harbin Engineering University, 150001 Harbin, China
| | - Boyue Liu
- School of Environmental and Municipal Engineering, Tianjin Chengjian University, 300384 Tianjin, China
| | - Hao Wei
- Key Laboratory of Superlight Material and Surface Technology of Ministry of Education, College of Material Science and Chemical Engineering, Harbin Engineering University, 150001 Harbin, China
| | - Ning Ma
- Key Laboratory of Superlight Material and Surface Technology of Ministry of Education, College of Material Science and Chemical Engineering, Harbin Engineering University, 150001 Harbin, China
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Li J, Jiang H, Ouyang X, Han S, Wang J, Xie R, Zhu W, Ma N, Wei H, Jiang Z. CaCO 3/Tetraethylenepentamine-Graphene Hollow Microspheres as Biocompatible Bone Drug Carriers for Controlled Release. ACS APPLIED MATERIALS & INTERFACES 2016; 8:30027-30036. [PMID: 27753474 DOI: 10.1021/acsami.6b10697] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
CaCO3 is one kind of important biological mineral, which widely exists in coral, shell, and other organisms. Since it is similar to bone tissue elements and has good biocompatibility, it was very suitable as a candidates for bone drug carriers. In this work, we used tetraethylenepentamine-graphene (rGO-TEPA) sheet matrices induction of CaCO3 mineralization and successfully constructed CaCO3/rGO-TEPA drug carriers with a hollow structure and rough surface. As potential drug carriers, doxorubicin (DOX) loading and release measurements were carried out. It showed that load efficiency was 94.7% and the release efficiencies were 13.8% and 91.7% at values of pH 7.4 and 5.0. The as-prepared drug carriers showed some appealing advantages, such as the pH-sensitive release characteristics and mild storage-release behaviors. The excellent biocompatibility and nontoxicity of CaCO3/rGO-TEPA hybrid microspheres were tested by the cell viability of mouse preosteoblast cells (MC3T3-E1). And cytotoxicity with human osteosarcoma cells (MG-63) was carried out to demonstrate the drug release effect in the cells system. Therefore, the CaCO3/rGO-TEPA hybrid microspheres would be a competitive alternative in bone drug carriers.
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Affiliation(s)
- Jie Li
- Key Laboratory of Superlight Material and Surface Technology of Ministry of Education, College of Material Science and Chemical Engineering, Harbin Engineering University , Harbin 150001, China
- Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University , Tianjin 300072, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) , Tianjin 300072, China
| | - Hongkun Jiang
- Key Laboratory of Superlight Material and Surface Technology of Ministry of Education, College of Material Science and Chemical Engineering, Harbin Engineering University , Harbin 150001, China
| | - Xiao Ouyang
- Key Laboratory of Superlight Material and Surface Technology of Ministry of Education, College of Material Science and Chemical Engineering, Harbin Engineering University , Harbin 150001, China
| | - Shihui Han
- Key Laboratory of Superlight Material and Surface Technology of Ministry of Education, College of Material Science and Chemical Engineering, Harbin Engineering University , Harbin 150001, China
| | - Jun Wang
- Key Laboratory of Superlight Material and Surface Technology of Ministry of Education, College of Material Science and Chemical Engineering, Harbin Engineering University , Harbin 150001, China
| | - Rui Xie
- Tumor Hospital of Harbin Medical University , Harbin 150081, China
| | - Wenting Zhu
- Tumor Hospital of Harbin Medical University , Harbin 150081, China
| | - Ning Ma
- Key Laboratory of Superlight Material and Surface Technology of Ministry of Education, College of Material Science and Chemical Engineering, Harbin Engineering University , Harbin 150001, China
| | - Hao Wei
- Key Laboratory of Superlight Material and Surface Technology of Ministry of Education, College of Material Science and Chemical Engineering, Harbin Engineering University , Harbin 150001, China
| | - Zhongyi Jiang
- Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University , Tianjin 300072, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) , Tianjin 300072, China
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