Nanomaterials
·
2022
·Vol. 12
·期 19
·3403
·
IF 5.719
Dandan Yan,Zhi Yu,Tingting Zou,Yucai Lin,Wenchi Kong,Jianjun Yang
The acquiring of superhydrophilic surfaces attracts the strong interest in self-cleaning, anti-fogging and anti-icing fields based on the unique features. However, the persistent time of superhydrophilic surfaces is still facing a big challenge because of easily adsorbing hydrophobic groups. Here, we propose a strategy to achieve a superhydrophilicity persisting for an unprecedently long time on sapphire surfaces, by compounding the femtosecond laser-induced hierarchical structures and the subsequent varnish of TiO2. The superhydrophilic effect (with a contact angle of CA = 0°) created by our method can be well prolonged to at least 180 days, even for its storage in air without additional illumination of UV lights. Based on comprehensive investigations, we attribute the underlying mechanisms to the coordination of laser-induced metal ions on the material surface via TiO2doping, which not only prevents the adsorption of the nonpolar hydrocarbon groups, but also modulates the photo-response properties of TiO2. In addition, further experiments demonstrate the excellent anti-fogging properties of our prepared samples. This investigation provides a new perspective for further enhancing the durability of superhydrophilicity surfaces.Keywords:femtosecond laser;long-time superhydrophilicity;sapphire;TiO2
研究领域:
材料科学
·
表面工程学
✓ 已验证
DOI
PubMed
高影响因子
Materials
·
2024
·Vol. 17
·期 15
·3812
·
IF 3.1
Shaohong Liu,Hairui Liu,Limin Zhou,Hao Cui,Manmen Liu,Li Chen,Ming Wen,Haigang Dong,Feng Liu,Wei Wang,Song Li
A novel AgCuTi brazing foil with a unique microstructure was developed, which could achieve strong vacuum brazing of Ti6Al4V (TC4) and sapphire. The brazing foil was composed of Ag solid solution (Ag(s,s)), Cu solid solution (Cu(s,s)), and layered Ti-rich phases, and had a low liquidus temperature of 790 °C and a narrow melting range of 16 °C, facilitating the defect-free joining of TC4 and sapphire. The sapphire/TC4 joint fabricated by using this novel AgCuTi brazing foil exhibited an outstanding average shear strength of up to 132.2 MPa, which was the highest value ever reported. The sapphire/TC4 joint had a characteristic structure, featuring a brazing seam reinforced by TiCu particles and a thin Ti3(Cu,Al)3O reaction layer of about 1.3 μm. The fracture mechanism of the sapphire/TC4 joint was revealed. The crack originated at the brazing seam with TiCu particles, then propagated through the Ti3(Cu,Al)3O reaction layer, detached the reaction layer from the sapphire, and finally penetrated into the sapphire. This study offers valuable insights into the design of active brazing alloys and reliable metal–ceramic bonding.
研究领域:
材料科学
·
焊接工程
✓ 已验证
DOI
PubMed
高影响因子
Nanomaterials
·
2022
·Vol. 12
·期 18
·3238
·
IF 5.719
Long Xu,Yuehan Cao,Tianwei Song,Caixia Xu
In this work, low-threshold resonant lasing emission was investigated in undoped and Mg-doped GaN thin films on interfacial designed sapphire substrates. The scattering cross-section of the periodic resonant structure was evaluated by using the finite difference time domain (FDTD) method and was found to be beneficial for reducing the threshold and enhancing the resonant lasing emission within the periodic structures. Compared with undoped and Si-doped GaN thin films, p-type Mg-doped GaN thin films demonstrated a better lasing emission performance. The lasing energy level system and defect densities played vital roles in the lasing emission. This work is beneficial to the realization of multifunctional applications in optoelectronic devices.Keywords:gallium nitride;lasing action;resonant structure;patterned sapphire substrate
研究领域:
光学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Manufacturing Processes
·
2023
·
IF 6.2
Shuye Zhang,Jincheng Lin,Ce Wang,Peng He,Wei Wang,Xinfei Zhang,Tong Wu,Han Mei,Yue Liu,Panpan Lin,Tiesong Lin
The brazed joint of sapphire transparent ceramic and Kovar alloy was prepared using AgCuTi and AgCuTiB composite filler, and the main focus was the effect of B element on the wetting behavior, interface composition and joint mechanical performance. The reliable joint of sapphire transparent ceramic and Kovar alloy was obtained by vacuum brazing with AgCu28-6Ti-0.45B (wt%) composite filler. The typical interfacial structure of the joint brazed at 825 °C for 10 min was determined as sapphire/Ti 3 Cu 3 O/Ag(s,s) + Cu(s,s) + disperse TiB/TiFe 2 + TiNi 3 /Kovar. The results showed that the addition of B could contributed to an optimized interfacial structure via (i) in-situ forming fine TiB whisker reinforcement phase and refining the interface structure and (ii) reducing the diffusion degree of alloy side elements to inhibit the generation of brittle phase, and the maximum shear strength of the joint with AgCu28-6Ti-0.45B (wt%) reached 125 MPa more than twice the joint without B additive. On the other hand, the wetting experiment showed that the addition of B as a solid particle decreased the fluidity of the composite filler, and when the addition of B was excessive, no dense TiB whiskers were produced in the interface. This study provides ideas for the optimization and improvement of sapphire composite connection, and points out that the generation of reinforcing phase is accompanied by the reduction of fluidity, so it is necessary to reasonably control the proportion of reinforcing phase.
研究领域:
材料科学
·
焊接工程
✓ 已验证
产品关联
DOI
高影响因子
Smart Materials and Structures
·
2020
·Vol. 29
·期 11
·114003
·
IF 3.613
Jisheng Pan,Zhijun Chen,Qiusheng Yan
To study the rheological properties and polishing performance of magnetorheological fluids (MRFs) prepared with SiO2@carbonyl iron (CI) core-shell particles, SiO2@CI core-shell particles with different shell thicknesses were synthesized by an improved Stöber method controlling the amount of tetraethyl orthosilicate (TEOS). Then, four types of MRFs which dispersed with core-shell particles with thin shells, core-shell particles with thick shells, SiO2 particles, or carbonyl iron were prepared for sapphire polishing. The results show that the rheological properties of MRF based on thicker shell SiO2@CI are enhanced compared to those of MRFs prepared by dispersing abrasive and CI. Comparing with other MRFs, sapphire can obtain better surface quality when using thicker shell SiO2@CI. The MRF fabricated by SiO2@CI core-shell particles can increase the contact area between the abrasive and the workpiece and enhance the contact stress, which improves the solid-phase reaction rate and mechanical removal efficiency of silica and sapphire, thereby improve the polishing efficiency.
研究领域:
材料科学
·
机械工程
·
表面工程
✓ 已验证
DOI
高影响因子
CRYSTENGCOMM
·
2024
·Vol. 26
·期 19
·2544-2550
·
IF 2.6
Songhao Wu,Chicheng Ma,Han Yang,Zichun Liu,Yuanxiao Ma,Ran Yao,Yiyun Zhang,Hua Yang,Xiaoyan Yi,Junxi Wang,Yeliang Wang
High-quality β-(AlxGa1−x)2O3 thin films are fabricated through face-to-face annealing on sapphire substrates covered with epitaxial Ga2O3. Al atoms during high-temperature annealing are uniformly diffused from the sapphire substrate into the overlying Ga2O3 for (AlxGa1−x)2O3 formation. The transformation of the (−201) crystal facet into the (300) crystal facet is observed, which is likely due to the lowest E(hkl)surf of the (100) surface. The crystallinity can be further improved with increasing the annealing temperatures and the duration of the thermal treatment under a tolerance limit of 1400 °C, which also increases the Al content to 0.68 in β-(AlxGa1−x)2O3 with a bandgap of up to 6.0 eV. As a result, highly-crystalline (300)-plane β-(AlxGa1−x)2O3 is obtained with a low X-ray diffraction (XRD) full width at half maximum (FWHM) at around 0.08° (288 arcsec). These findings contribute to the understanding of the preparation of high-quality β-(AlxGa1−x)2O3 films on sapphire substrates.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
Chen Zhou,Xiangyang Xu,Lei Dai,Haiming Gong,Shuntian Lin
Driven by electrostatic attraction, Ce 4+ ions or/and positively charged detonation nanodiamond (DND) particles can absorb onto negatively charged polystyrene (PS) spherical colloids. Three types of core-shell structured composite abrasives, PS@CeO 2 , PS@DND and PS@CeO 2 /DND, can thus be assembled. When PS@CeO 2 and PS@DND were used to polish sapphire wafer at pad rotating speed of 120–150 r/min and load pressure of ~3 kg, the material removing rate (MRR) exceeded 1.0 μm h −1 , 10–20 % higher than unitary abrasives. The surface profile roughness (Ra) for wafer polished by these two composite abrasives was respectively 1.25 and 0.63 nm, which is superior to CeO 2 (Ra = 1.38 nm) and DND (Ra = 1.29 nm). When using PS@CeO 2 /DND, the polishing interface area can be increased owing to the combined effect of elastic PS spheres and intensively coated CeO 2 and DND. Meanwhile, the synergistic mechanism of sapphire-CeO 2 chemical reaction and the strong mechanical abrasion of DND particles benefit the polishing efficiency. MRR for this ternary composite abrasive attained 1.4–1.7 μm h −1 while sapphire can be smoothed to a sub-nanoscale roughness.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
CARBON
·
2020
·
IF 8.821
Yang Chen,Ke Jiang,Hang Zang,Jianwei Ben,Shanli Zhang,Zhiming Shi,Yuping Jia,Wei Lü,Dabing Li,Xiaojuan Sun
Growth of graphene on dielectric substrates is crucial for its use in various electronic and optoelectronic devices , which may avoid the additional extrinsic defects and residual pollution originating from the essential transfer process of graphene grown by chemical vapor deposition on metal foils. However, the growth of high-quality and wafer-scale graphene on dielectric substrates is now still a challenge. Herein, we report the growth of graphene from solid polymer carbon source on various substrates under the assistance of Nickel/SiO 2 capping layer. The wafer-scale graphene with excellent uniformity and continuity was achieved on 2 inch sapphire substrates . The dynamics of the graphene growth were proposed, which mainly consist of polymer carbonization , carbon dissolution, segregation and precipitation. The graphene was also grown on undoped GaN to serve as the carrier transport channel of ultraviolet photodetectors , exhibiting a 4 A/W response. The growth of high-quality and wafer-scale graphene on dielectric substrates reported by present work would promote commercial application of the graphene-based electronic and optoelectronic devices.
研究领域:
材料科学
·
光电子学
·
半导体器件
✓ 已验证
DOI
高影响因子
LANGMUIR
·
2018
·
IF 3.789
Tianyi Han,Chenhui Zhang,Jianbin Luo
Superlubricity based on hydration lubrication provides a near-frictionless lubrication state for the extreme reduction of friction in aqueous conditions. Nevertheless, how to obtain the hydration superlubricity under macroscale conditions with higher load-carrying capacity still remains a challenge and the mechanisms governing macroscale superlubricity with hydrated ions are still not well comprehended. Here, we demonstrate that macroscale superlubricity based on hydrated alkali metal ions (Li+, Na+, K+) can be realized under high contact pressure between the Si3N4 ball and sapphire disk. The ultralow friction coefficients of 0.005 are obtained under average contact pressure up to 0.25 GPa by a universal micro-tribometer after a running-in period with acid solutions. The results reveal that running-in stage with acid solutions can not only make the worn region smoother but also generate a silica layer that is easy to shear, which provides excellent boundary lubrication. The hydration superlubricity occurs because hydration shells surrounding the alkali metal ions could generate the hydration repulsive force to sustain a large normal load and have a fluid response to shear simultaneously. These findings pave the way to the scale-up of hydration superlubricity and thus to the wide application of new water-based lubricants.
研究领域:
材料科学
·
摩擦学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
OPTICS AND LASER TECHNOLOGY
·
2025
·
IF 5
Zhuo-Yu Jin,Chu Cao,Nuerguli Kari,Dian-Yun Zhang,Qi Wang
Surface plasmon resonance (SPR) sensors are currently applied in various fields, driving the development of precise detection technologies. However, few designs effectively balance ease of fabrication, high detection performance, and structural stability. To address this challenge, we developed an SPR sensor with a sapphire prism-Au/Gallium Nitride (GaN)/Au composite film structure. The GaN thin film enhances sensitivity, while the coupling between the dual Au layers and sapphire reduces the full width at half maximum (FWHM) and improves sensor stability. Simulation results indicate a significant increase in the electric field intensity at the sensor surface. Experimental results demonstrate that the structure exhibits excellent long-term stability. Compared with conventional Au film sapphire prism SPR sensors, this design achieves a 3.14-fold increase in sensitivity and a 5.43-fold improvement in the figure of merit (FOM). This study presents a novel approach to further enhancing SPR sensor performance and highlights the potential applications of this structure in detection technologies.
研究领域:
光学传感
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
WEAR
·
2025
·
IF 6.1
Guangen Zhao,Jianxiong Chen,Yongchao Xu,Cheng Peng,Qianting Wang
It is a great challenge to produce ultra-smooth surface of sapphire wafers at high material removal rate (MRR) using green slurry in semi-fixed abrasive polishing. A novel environmentally friendly polishing slurry was developed by preparing abrasives and complexing agents to improve surface quality and polishing efficiency. The SiO 2 and diamond/SiO 2 composite abrasives were successfully prepared by a simplified sol-gel strategy, exhibiting high purity, homogeneous particle size, and excellent dispersibility. Based on the semi-fixed polishing technology, the green polishing performance of sapphire wafers using different types of abrasives alone and in combination with complexing agents was investigated. The experimental results demonstrated that the novel slurry containing triisopropanolamine (TIPA) and diamond/SiO 2 composite abrasive had superior polishing performance. Compared with the traditional diamond slurry, the surface roughness of the novel slurry was reduced by 24.4 % to 6.2 nm (Ra), while the MRR was increased by 65.4 %. Through electrochemical experiments, molecular simulations, and infrared analysis, the improved polishing performance of the composite abrasives with TIPA may be attributed to the complexation of TIPA and the optimization of interfacial contact behavior. The analysis of wear debris and polished sapphire wafer surface further pointed out that the deformation reduced the indentation depth while enhancing the reactivity of the friction chemistry. The diamond/SiO 2 composite abrasives with TIPA slurry accelerated the generation and removal of the reaction layer consisting of AlOOH, Al-OH, and Al 2 Si 2 O 7 , realizing the optimal synergy between mechanical wear and tribochemistry, which significantly improved the polishing quality.
研究领域:
材料科学
·
表面工程
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2019
·
IF 2.781
Hong Lei,Tingting Liu,Lei Xu
SiO 2 abrasive is one of the most effective abrasives used in chemical mechanical polishing (CMP) due to its uniform size, good dispersibility and good chemical reactivity. In this paper, a series of novel Sm-doped colloidal SiO 2 composite abrasives were synthesized by seed-induced growth method. The composite abrasives were characterized by using scanning electron microscopy, time-of-flight secondary ion mass spectrometry analysis (TOF-SIMS) and X-ray photoelectron spectroscopy (XPS). The structure of the composite abrasive is core-shell type with silica as a core and a coated growth layer (including SiO 2 , Sm 2 Si 2 O 7 and Sm(OH) 3 as shell via chemical bonds and hydrogen bonds . The CMP properties of the composite abrasives on sapphire substrates were further studied and the results show that the Sm-doped colloidal SiO 2 composite abrasives give lower polished surface roughness (Ra) and higher MRR than that of the pure colloidal SiO 2 abrasive under the same polishing conditions. By TOF-SIMS and XPS analyses on the polished slurries, the acting mechanisms of Sm-doped colloidal SiO 2 composite abrasives on sapphire were explored also.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）