The Experts below are selected from a list of 10488 Experts worldwide ranked by ideXlab platform
Linmao Qian - One of the best experts on this subject based on the ideXlab platform.
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simple and low cost nanofabrication process of nanoimprint templates for high quality master gratings friction induced Selective Etching
Applied Surface Science, 2018Co-Authors: Hongbo Wang, Shulan Jiang, Cheng Chen, Linmao QianAbstract:Abstract Gratings are core components in biochemical analysis, ultra-precision machine tools, and astronomy. However, the high complexity and cost of conventional fabrication processes severely prevent its wide commercial application. Here, we report a simple and inexpensive fabrication process based on friction-induced Selective Etching. A series of crucial technological issues in the fabrication process were systematically investigated and optimized to obtain high precision and practical master gratings. Compared with the conventional surface cleaning method, the magnetic stirring-assisted KOH Etching process can nondestructively and completely remove chemical sediments. Moreover, the sharp and smooth diamond tip is less sensitive to the tip profile and can easily fabricate high-quality grating structures compared with the blunt diamond tip. Particularly, the line width/density and micromorphology of grating structures can be effectively controlled by the scratching load and Etching time. By integrating the mature UV nanoimprint lithography technology, the master gratings fabricated by this improved process can be excellently replicated on the polymer surface. This work presents a solid progress toward the simple and inexpensive fabrication of Si-based master gratings and also provides detailed reference for fabricating intractable blazed and circular gratings.
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temperature dependent nanofabrication on silicon by friction induced Selective Etching
Nanoscale Research Letters, 2016Co-Authors: Chenning Jin, Chen Xiao, Lei Chen, Linmao QianAbstract:Friction-induced Selective Etching provides a convenient and practical way for fabricating protrusive nanostructures. A further understanding of this method is very important for establishing a controllable nanofabrication process. In this study, the effect of Etching temperature on the formation of protrusive hillocks and surface properties of the etched silicon surface was investigated. It is found that the height of the hillock produced by Selective Etching increases with the Etching temperature before the collapse of the hillock. The temperature-dependent Selective Etching rate can be fitted well by the Arrhenius equation. The Etching at higher temperature can cause rougher silicon surface with a little lower elastic modulus and hardness. The contact angle of the etched silicon surface decreases with the Etching temperature. It is also noted that no obvious contamination can be detected on silicon surface after Etching at different temperatures. As a result, the optimized condition for the Selective Etching was addressed. The present study provides a new insight into the control and application of friction-induced Selective nanofabrication.
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maskless and low destructive nanofabrication on quartz by friction induced Selective Etching
Nanoscale Research Letters, 2013Co-Authors: Chenfei Song, Bingjun Yu, Xiaoying Li, Hanshan Dong, Linmao QianAbstract:A low-destructive friction-induced nanofabrication method is proposed to produce three-dimensional nanostructures on a quartz surface. Without any template, nanofabrication can be achieved by low-destructive scanning on a target area and post-Etching in a KOH solution. Various nanostructures, such as slopes, hierarchical stages and chessboard-like patterns, can be fabricated on the quartz surface. Although the rise of Etching temperature can improve fabrication efficiency, fabrication depth is dependent only upon contact pressure and scanning cycles. With the increase of contact pressure during scanning, Selective Etching thickness of the scanned area increases from 0 to 2.9 nm before the yield of the quartz surface and then tends to stabilise after the appearance of a wear. Refabrication on existing nanostructures can be realised to produce deeper structures on the quartz surface. Based on Arrhenius fitting of the Etching rate and transmission electron microscopy characterization of the nanostructure, fabrication mechanism could be attributed to the Selective Etching of the friction-induced amorphous layer on the quartz surface. As a maskless and low-destructive technique, the proposed friction-induced method will open up new possibilities for further nanofabrication.
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fabrication mechanism of friction induced Selective Etching on si 100 surface
Nanoscale Research Letters, 2012Co-Authors: Chenfei Song, Bingjun Yu, Xiaoying Li, Linmao Qian, Hanshan Dong, Zhongrong ZhouAbstract:As a maskless nanofabrication technique, friction-induced Selective Etching can easily produce nanopatterns on a Si(100) surface. Experimental results indicated that the height of the nanopatterns increased with the KOH Etching time, while their width increased with the scratching load. It has also found that a contact pressure of 6.3 GPa is enough to fabricate a mask layer on the Si(100) surface. To understand the mechanism involved, the cross-sectional microstructure of a scratched area was examined, and the mask ability of the tip-disturbed silicon layer was studied. Transmission electron microscope observation and scanning Auger nanoprobe analysis suggested that the scratched area was covered by a thin superficial oxidation layer followed by a thick distorted (amorphous and deformed) layer in the subsurface. After the surface oxidation layer was removed by HF Etching, the residual amorphous and deformed silicon layer on the scratched area can still serve as an Etching mask in KOH solution. The results may help to develop a low-destructive, low-cost, and flexible nanofabrication technique suitable for machining of micro-mold and prototype fabrication in micro-systems.
Jianlin Shi - One of the best experts on this subject based on the ideXlab platform.
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a facile in situ hydrophobic layer protected Selective Etching strategy for the synchronous synthesis modification of hollow or rattle type silica nanoconstructs
Journal of Materials Chemistry, 2012Co-Authors: Kun Zhang, Yu Chen, Hangrong Chen, Yuanyi Zheng, Xia Wang, Lijun Wang, Deping Zeng, Jianlin ShiAbstract:A novel and general in situ hydrophobic shell-protected Selective Etching strategy has been developed to synchronously synthesize and modify hollow mesoporous silica nanoparticles (HMSNs) and rattle-type mesoporous silica nanoparticles (RMSNs) with well-defined morphology, effectively avoiding the drawbacks of post-modification. The key point of the strategy lies in the hydrophilicity differences between the pure silica inner core and the organic hybrid silica shell, which results in the preferential Etching of the pure silica inner core. Except that amino group functionalized HMSNs (amino-HMSNs) can be synthesized via this strategy, it can be readily applied for the synthesis of HMSNs and RMSNs synchronously grafted with different kinds of functional groups by employing other silane coupling agents, directly indicating the generality of this strategy. Furthermore, adding no additional reduction agents, the amino-HMSNs can be regarded as nanoreactors, and a distinctively heterogeneous rattle-type structure, Au@HMSN/Au, with an entrapped size-tunable Au nanoparticle and some small Au nanocrystals embedded in the hollow cavity and shell of each nanoparticle, respectively, is obtained. As hybrid ultrasound contrast agents (UCAs), unlike micro-sized organic UCAs merely confined to blood pool imaging, the as-synthesized nano-sized amino-HMSNs can achieve excellent in vitro ultrasound imaging, and potentially be applied in cell-level imaging. More importantly, relying on the process merits of our strategy, such as the doping of silane coupling agents and no calcination treatment, amino-HMSNs exhibit enhanced ultrasound imaging to some certain extent compared to the calcined ones.
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hollow rattle type mesoporous nanostructures by a structural difference based Selective Etching strategy
ACS Nano, 2010Co-Authors: Yu Chen, Hangrong Chen, Limin Guo, Qianjun He, Feng Chen, Jian Zhou, Jingwei Feng, Jianlin ShiAbstract:A novel “structural difference-based Selective Etching” strategy has been developed to fabricate hollow/rattle-type mesoporous nanostructures, which was achieved by making use of the structural differences, rather than traditional compositional differences, between the core and the shell of a silica core/mesoporous silica shell structure to create hollow interiors. Highly dispersed hollow mesoporous silica spheres with controllable particle/pore sizes could be synthesized by this method, which show high loading capacity (1222 mg/g) for anticancer drug (doxorubicin). Hemolyticity and cytotoxicity assays of hollow mesoporous silica spheres were conducted, and the synthesized hollow mesoporous silica spheres with large pores show ultrafast immobilization of protein-based biomolecules (hemoglobin). On the basis of this strategy, different kinds of heterogeneous rattle-type nanostructures with inorganic nanocrystals, such as Au, Fe2O3, and Fe3O4 nanoparticles, as the core and mesoporous silica as the shell wer...
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hollow rattle type mesoporous nanostructures by a structural difference based Selective Etching strategy
ACS Nano, 2010Co-Authors: Yu Chen, Hangrong Chen, Limin Guo, Feng Chen, Jian Zhou, Jingwei Feng, Jianlin ShiAbstract:A novel "structural difference-based Selective Etching" strategy has been developed to fabricate hollow/rattle-type mesoporous nanostructures, which was achieved by making use of the structural differences, rather than traditional compositional differences, between the core and the shell of a silica core/mesoporous silica shell structure to create hollow interiors. Highly dispersed hollow mesoporous silica spheres with controllable particle/pore sizes could be synthesized by this method, which show high loading capacity (1222 mg/g) for anticancer drug (doxorubicin). Hemolyticity and cytotoxicity assays of hollow mesoporous silica spheres were conducted, and the synthesized hollow mesoporous silica spheres with large pores show ultrafast immobilization of protein-based biomolecules (hemoglobin). On the basis of this strategy, different kinds of heterogeneous rattle-type nanostructures with inorganic nanocrystals, such as Au, Fe(2)O(3), and Fe(3)O(4) nanoparticles, as the core and mesoporous silica as the shell were also prepared. This strategy could be extended as a general approach to synthesize various hollow/rattle-type nanostructures by creating adequate structural differences between cores and shells in core/shell structures in nanoscale.
Shaoming Huang - One of the best experts on this subject based on the ideXlab platform.
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Selective Etching induces Selective growth and controlled formation of various platinum nanostructures by modifying seed surface free energy
ACS Nano, 2012Co-Authors: Nini Fan, Yun Yang, Wenfang Wang, Lijie Zhang, Wei Chen, Chao Zou, Shaoming HuangAbstract:We present a strategy to achieve heterogeneous seeded growth on nanoparticle (NP) surfaces and construct various Pt nanostructures (cage- and ring-like) by using Selective Etching as surface-free-energy-distribution modifier. Preprepared Au polyhedron NPs (octahedron, decahedron, nanorod, and nanoplate) are mixed with KI, H2PtCl6, and surfactant. Under heating, KI is first oxidized to I2, which then Selectively etches the edges of Au polyhedrons. Consequently, the partial removal of surface Au atoms creates highly active sites (exposed high-index facets, atom steps, and kinks) on the etched edges. Then the reduced Pt0 atoms deposit on the etched edges preferentially and grow further, generating bimetallic nanostructures, Au octahedrons, or decahedrons with edges coated by Pt. The Pt layer protects the Au on the etched edges against further Etching, changing the Etching route and causing the Au on {111} facets without a Pt layer to be etched. After the Au is removed completely from the bimetallic nanostruc...
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Selective Etching induces Selective growth and controlled formation of various platinum nanostructures by modifying seed surface free energy
ACS Nano, 2012Co-Authors: Nini Fan, Yun Yang, Wenfang Wang, Lijie Zhang, Wei Chen, Chao Zou, Shaoming HuangAbstract:We present a strategy to achieve heterogeneous seeded growth on nanoparticle (NP) surfaces and construct various Pt nanostructures (cage- and ring-like) by using Selective Etching as surface-free-energy-distribution modifier. Preprepared Au polyhedron NPs (octahedron, decahedron, nanorod, and nanoplate) are mixed with KI, H(2)PtCl(6), and surfactant. Under heating, KI is first oxidized to I(2), which then Selectively etches the edges of Au polyhedrons. Consequently, the partial removal of surface Au atoms creates highly active sites (exposed high-index facets, atom steps, and kinks) on the etched edges. Then the reduced Pt(0) atoms deposit on the etched edges preferentially and grow further, generating bimetallic nanostructures, Au octahedrons, or decahedrons with edges coated by Pt. The Pt layer protects the Au on the etched edges against further Etching, changing the Etching route and causing the Au on {111} facets without a Pt layer to be etched. After the Au is removed completely from the bimetallic nanostructures, ring-like, frame-like, and octahedral cage-like Pt nanostructures form. The evolution from Au polyhedrons to Pt ring or octahedron cage is investigated systematically by high-resolution transmission electron microscopy, transmission electron microscopy, scanning electron microscopy, energy-dispersive X-ray, scanning transmission electron microscopy, and high-angle annular dark field.
Chenfei Song - One of the best experts on this subject based on the ideXlab platform.
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maskless and low destructive nanofabrication on quartz by friction induced Selective Etching
Nanoscale Research Letters, 2013Co-Authors: Chenfei Song, Bingjun Yu, Xiaoying Li, Hanshan Dong, Linmao QianAbstract:A low-destructive friction-induced nanofabrication method is proposed to produce three-dimensional nanostructures on a quartz surface. Without any template, nanofabrication can be achieved by low-destructive scanning on a target area and post-Etching in a KOH solution. Various nanostructures, such as slopes, hierarchical stages and chessboard-like patterns, can be fabricated on the quartz surface. Although the rise of Etching temperature can improve fabrication efficiency, fabrication depth is dependent only upon contact pressure and scanning cycles. With the increase of contact pressure during scanning, Selective Etching thickness of the scanned area increases from 0 to 2.9 nm before the yield of the quartz surface and then tends to stabilise after the appearance of a wear. Refabrication on existing nanostructures can be realised to produce deeper structures on the quartz surface. Based on Arrhenius fitting of the Etching rate and transmission electron microscopy characterization of the nanostructure, fabrication mechanism could be attributed to the Selective Etching of the friction-induced amorphous layer on the quartz surface. As a maskless and low-destructive technique, the proposed friction-induced method will open up new possibilities for further nanofabrication.
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fabrication mechanism of friction induced Selective Etching on si 100 surface
Nanoscale Research Letters, 2012Co-Authors: Chenfei Song, Bingjun Yu, Xiaoying Li, Linmao Qian, Hanshan Dong, Zhongrong ZhouAbstract:As a maskless nanofabrication technique, friction-induced Selective Etching can easily produce nanopatterns on a Si(100) surface. Experimental results indicated that the height of the nanopatterns increased with the KOH Etching time, while their width increased with the scratching load. It has also found that a contact pressure of 6.3 GPa is enough to fabricate a mask layer on the Si(100) surface. To understand the mechanism involved, the cross-sectional microstructure of a scratched area was examined, and the mask ability of the tip-disturbed silicon layer was studied. Transmission electron microscope observation and scanning Auger nanoprobe analysis suggested that the scratched area was covered by a thin superficial oxidation layer followed by a thick distorted (amorphous and deformed) layer in the subsurface. After the surface oxidation layer was removed by HF Etching, the residual amorphous and deformed silicon layer on the scratched area can still serve as an Etching mask in KOH solution. The results may help to develop a low-destructive, low-cost, and flexible nanofabrication technique suitable for machining of micro-mold and prototype fabrication in micro-systems.
Herbe Hornsolle - One of the best experts on this subject based on the ideXlab platform.
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micro and nanostructures inside sapphire by fs laser irradiation and Selective Etching
Optics Express, 2008Co-Authors: D Wortma, Jens Gottma, N And, Herbe HornsolleAbstract:The fabrication of microchannels and self-assembled nanostructures in the volume of sapphire was performed by femtosecond laser irradiation followed by chemical Etching with aqueous solution of HF acid. Depending on the focusing conditions self-organized nanostructures or elliptical microchannels are produced. While the dimensions in two directions are on a micro- respectively nanoscale, feature lengths of up to 1 mm are achieved. This comes out to aspect ratios of more than 1000. This fabrication technique is potentially usable for photonic crystal based integrated optical elements or microfluidic devices for applications in life science, biology or chemistry.
