Preparation and Properties of PTFE/SA Blend Membrane

Poly (tetrafluoroethylene) (PTFE)/Salt alginate (SA) flat membranes were prepared from a mixture of PTFE concentrated dispersion and Sodium alginate (NaAlg) aqueous solution. The chemical constitutions of the PTFE/SA membranes before and after sintering were investigated with FTIR. Meanwhile, TGA and contact angle to water were utilized to analyze the thermal stability and hydrophobic property. Moreover, effects of sintering conditions on the properties and morphologies of the membranes were also investigated. Results showed that SA was decomposed in the sintering process, and the membranes maintained excellent thermal stability and strong hydrophobicity. In addition, it was beneficial for the membranes to obtain high air flux by short sintering time and the membranes had different surface morphologies by different cooling rates.

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Effect of Sintering Conditions on the Mechanical Strength of Cu-Sintered Joints for High-Power Applications

Materials ◽

10.3390/ma11112105 ◽

2018 ◽

Vol 11 (11) ◽

pp. 2105 ◽

Cited By ~ 8

Author(s):

Jeong-Won Yoon ◽

Jong-Hoon Back

Keyword(s):

Shear Strength ◽

Low Cost ◽

Sintering Process ◽

Bonding Pressure ◽

Sintering Time ◽

Sinter Bonding ◽

Sintering Conditions ◽

Metallic Bonding ◽

Mechanical Strengths ◽

Direct Bond Copper

In this study, the feasibility of low-cost Cu-sintering technology for power electronics packaging and the effect of sintering conditions on the bonding strength of the Cu-sintered joint have been evaluated. A Cu paste with nano-sized Cu powders and a metal content of ~78% as a high-temperature bonding material was fabricated. The sinter-bonding reactions and mechanical strengths of Cu-sintered joints were evaluated at different sinter bonding pressures, temperatures, and durations during the sintering process. The shear strength of the Cu-sintered joints increased with increasing sintering pressure. Good interfacial uniformity and stable metallurgical microstructures were observed in the Cu joints sintered at a high sintering pressure of 10 MPa, irrespective of the sintering time. It was confirmed that a high-pressure-assisted sintering process could create relatively dense sintered layers and good interfacial uniformity in the Cu-sintered joints, regardless of the sintering temperatures being in the range of 225–300 °C. The influence of the sinter bonding pressure on the shear strengths of the Cu-sintered joints was more significant compared to that of the sintering temperature. Durations of 10 min (at 300 °C) and 60 min (at 225 and 250 °C) are sufficient for complete sintering reactions between the Si chip and the direct bond copper (DBC) substrate. Relatively good metallic bonding and dense sintered microstructures created by a high sintering pressure of 10 MPa resulted in high shear strength in excess of 40 MPa of the Cu-sintered joints.

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Effect of carbonization on mechanical properties of halloysite nanotube-FRP nanocomposites with different morphological structures

Modern Physics Letters B ◽

10.1142/s0217984919400219 ◽

2019 ◽

Vol 33 (14n15) ◽

pp. 1940021

Author(s):

Yun-Hae Kim ◽

Ji-Su Choi ◽

Soo-Jeong Park

Keyword(s):

Thermal Stability ◽

Bonding Strength ◽

Basalt Fiber ◽

Morphological Structure ◽

Halloysite Nanotubes ◽

Interfacial Bonding ◽

Limiting Oxygen Index ◽

Excellent Thermal Stability ◽

Interfacial Bonding Strength ◽

Before And After

In this study, halloysite nanotubes (HNTs), an environmentally friendly inorganic nanomaterial, was added to epoxy matrix glass and basalt fiber reinforced plastics (GFRP and BFRP) by heat treatment of HNTs with crystalline and amorphous structure at [Formula: see text] and [Formula: see text]. Their interfacial bonding strength and effect of HNTs before and after carbonization by flame were analyzed. We found that the HNT/epoxy formed a physical barrier on the surface because of the char generated by carbonization. The barrier showed excellent thermal stability and limiting oxygen index in BFRP. The flexural strength after carbonization was low in the amorphous 1000HTHNT-BFRP with strong interfacial bonding. In other words, the morphological structure of the HNTs helped the improvement of the interfacial bonding strength; hence, the reinforcing effect of the HNTs on the thermal stability and mechanical strength before and after carbonization can be controlled.

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Microstructure studies of tungsten silicide schottky contacts on Gaas

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100126445 ◽

1987 ◽

Vol 45 ◽

pp. 328-329

Author(s):

Yih-Cheng Shih ◽

E. L. Wilkie

Keyword(s):

Thermal Stability ◽

Field Effect Transistors ◽

Schottky Contact ◽

Schottky Contacts ◽

Excellent Thermal Stability ◽

Barrier Heights ◽

Gaas Substrates ◽

Film Adhesion ◽

Threshold Voltages ◽

Thermal Stability Of

Tungsten silicides (WSix) have been successfully used as the gate materials in self-aligned GaAs metal-semiconductor-field- effect transistors (MESFET). Thermal stability of the WSix/GaAs Schottky contact is of major concern since the n+ implanted source/drain regions must be annealed at high temperatures (∼ 800°C). WSi0.6 was considered the best composition to achieve good device performance due to its low stress and excellent thermal stability of the WSix/GaAs interface. The film adhesion and the uniformity in barrier heights and ideality factors of the WSi0.6 films have been improved by depositing a thin layer of pure W as the first layer on GaAs prior to WSi0.6 deposition. Recently WSi0.1 has been used successfully as the gate material in 1x10 μm GaAs FET's on the GaAs substrates which were sputter-cleaned prior to deposition. These GaAs FET's exhibited uniform threshold voltages across a 51 mm wafer with good film adhesion after annealing at 800°C for 10 min.

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Boosted piezoelectricity with excellent thermal stability in tetragonal NaNbO3-based ceramics

Journal of Materials Chemistry A ◽

10.1039/d0ta10470a ◽

2020 ◽

Author(s):

Lu Wang ◽

Shengdong Sun ◽

Huajie Luo ◽

Yang Ren ◽

Hui Liu ◽

...

Keyword(s):

Thermal Stability ◽

Temperature Stability ◽

Lead Free ◽

Excellent Thermal Stability ◽

Lead Free Ceramics ◽

Piezoelectric Performance

The realization of high piezoelectric performance and excellent temperature stability simultaneously in lead-free ceramics is the key for replacing Pb-containing perovskites in industry. In this study, large piezoelectric performance (d33...

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High quality upconversion luminescence and excellent thermal stability of Yb3+, Er3+ codoped Sr3NaY(PO4)3F phosphors

Materials Research Bulletin ◽

10.1016/j.materresbull.2021.111306 ◽

2021 ◽

pp. 111306

Author(s):

Shiping Wang ◽

Bingye Zhang ◽

Ying Li ◽

Jinsu Zhang ◽

Baojiu Chen

Keyword(s):

Thermal Stability ◽

Upconversion Luminescence ◽

High Quality ◽

Excellent Thermal Stability ◽

Thermal Stability Of

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Microwave Sintering and Microwave Dielectric Properties of (1–x)Ca0.61La0.26TiO3-xNd(Mg0.5Ti0.5)O3 Ceramics

Materials ◽

10.3390/ma14020438 ◽

2021 ◽

Vol 14 (2) ◽

pp. 438

Author(s):

Shuwei Yang ◽

Bingliang Liang ◽

Changhong Liu ◽

Jin Liu ◽

Caisheng Fang ◽

...

Keyword(s):

Dielectric Properties ◽

Mobile Communications ◽

Sintering Temperature ◽

Microwave Sintering ◽

Microwave Dielectric Properties ◽

Conventional Heating ◽

Sintering Process ◽

Microwave Dielectric ◽

Sintering Time ◽

Frequency Temperature

The (1–x)Ca0.61La0.26TiO3-xNd(Mg0.5Ti0.5)O3 [(1–x)CLT-xNMT, x = 0.35~0.60] ceramics were prepared via microwave sintering. The effects of sintering temperature and composition on the phase formation, microstructure, and microwave dielectric properties were investigated. The results show that the microwave sintering process requires a lower sintering temperature and shorter sintering time of (1–x)CLT-xNMT ceramics than conventional heating methods. All of the (1–x)CLT-xNMT ceramics possess a single perovskite structure. With the increase of x, the dielectric constant (ε) shows a downward trend; the quality factor (Qf) drops first and then rises significantly; the resonance frequency temperature coefficient (τf) keeps decreasing. With excellent microwave dielectric properties (ε = 51.3, Qf = 13,852 GHz, τf = −1.9 × 10−6/°C), the 0.65CLT-0.35NMT ceramic can be applied to the field of mobile communications.

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Synthesis of Novel Arginine-Based Flame Retardant and Its Application in Lyocell Fabric

Molecules ◽

10.3390/molecules26123588 ◽

2021 ◽

Vol 26 (12) ◽

pp. 3588

Author(s):

Jiayi Chen ◽

Yansong Liu ◽

Jiayue Zhang ◽

Yuanlin Ren ◽

Xiaohui Liu

Keyword(s):

Fourier Transform ◽

Heat Release ◽

Flame Retardant ◽

Photoelectron Spectroscopy ◽

Fourier Transform Infrared ◽

Ftir Analysis ◽

Excellent Thermal Stability ◽

X Ray ◽

Cone Calorimeter Test ◽

Before And After

Lyocell fabrics are widely applied in textiles, however, its high flammability increases the risk of fire. Therefore, to resolve the issue, a novel biomass-based flame retardant with phosphorus and nitrogen elements was designed and synthesized by the reaction of arginine with phosphoric acid and urea. It was then grafted onto the lyocell fabric by a dip-dry-cure technique to prepare durable flame-retardant lyocell fabric (FR-lyocell). X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FTIR) analysis demonstrated that the flame retardant was successfully introduced into the lyocell sample. Thermogravimetric (TG) and Raman analyses confirmed that the modified lyocell fabric featured excellent thermal stability and significantly increased char residue. Vertical combustion results indicated that FR-lyocell before and after washing formed a complete and dense char layer. Thermogravimetric Fourier-transform infrared (TG-FTIR) analysis suggested that incombustible substances (such as H2O and CO2) were produced and played a significant fire retarding role in the gas phase. The cone calorimeter test corroborated that the peak of heat release rate (PHRR) and total heat release (THR) declined by 89.4% and 56.4%, respectively. These results indicated that the flame retardancy of the lyocell fabric was observably ameliorated.

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The influence of an ultra-high resistivity Ta underlayer on perpendicular magnetic anisotropy in Ta/Pt/Co/Pt heterostructures

RSC Advances ◽

10.1039/d0ra00459f ◽

2020 ◽

Vol 10 (19) ◽

pp. 11219-11224

Author(s):

Wei Zhang ◽

Xiaoxiong Jia ◽

Rui Wang ◽

Huihui Liu ◽

Zhengyu Xiao ◽

...

Keyword(s):

Thin Films ◽

Thermal Stability ◽

Magnetic Anisotropy ◽

High Stability ◽

Essential Role ◽

Perpendicular Magnetic Anisotropy ◽

Low Energy ◽

High Resistivity ◽

Excellent Thermal Stability ◽

Low Energy Consumption

Thin films with perpendicular magnetic anisotropy (PMA) play an essential role in the development of technologies due to their excellent thermal stability and potential application in devices with high density, high stability, and low energy consumption.

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