Study on dipolar orientation and relaxation characteristics of guest–host polymers affected by corona poling parameters

AbstractA new material for second-order nonlinear optics was synthesized, which was a copolymer of N-phenylmaleimide, 4-isopropenylphenol and 4'-[N-ethyl-N-(4-isopropenylphenoxyethyl) amino]-4”-nitroazobenzene (PMPD). PMPD films were poled by corona-poling technique. The optical nonlinearity of poled PMPD was measured by second harmonic generation (SHG) and electro-optic (EO) effect, and it was demonstrated that this polymer had large optical nonlinearity and a very long-time stability, as was expected. These properties were thought to be sufficient enough for practical EO devices. On the other hand, from the viewpoint of the sample preparation technique, poling conditions were investigated in order to achieve the highest possible dipolar orientation. As a result, it was found that the relationship between the electric resistance of polymer film and substrate was a critical factor for corona-poling efficiency. From a simple model, it was suggested that the poled PMPD film prepared onto the glass substrate with a resistance of ˜0.8 GΩ (at 160 °C) exhibits large SHG and EO coefficients, more than ˜500 × 10−9 e.s.u (d33 at λ = 1.064 μm) and ˜70 pm/V(r33 at λ = 632.8 nm), respectively. It should be noted that this expected values are approximately twice as much as obtained under conventional corona-poling conditions.

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ULTRONZE

Alloy Digest ◽

10.31399/asm.ad.cu0417 ◽

1981 ◽

Vol 30 (5) ◽

Keyword(s):

Corrosion Resistance ◽

Stress Relaxation ◽

Physical Properties ◽

Copper Alloy ◽

High Performance ◽

Copper Alloys ◽

Heat Treating ◽

Bend Strength ◽

Excellent Corrosion Resistance ◽

Relaxation Characteristics

Abstract ULTRONZE is a copper alloy also known as Olin Alloy 654. It bridges the gap between standard high-performance copper alloys and beryllium-copper alloys, thus enabling the design of parts with properties previously only attainable with more expensive materials. The alloy has superior stress-relaxation characteristics, good bend performance and excellent corrosion resistance. Among its typical uses are electrical connectors, fuse clips and relay springs. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and bend strength. It also includes information on corrosion resistance as well as forming, heat treating, and machining. Filing Code: Cu-417. Producer or source: Olin Brass.

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Research on the Stress-relaxation Characteristics of Cancer Cells Based on Atomic Force Microscope

Current Nanoscience ◽

10.2174/1573413711208010047 ◽

2012 ◽

Vol 8 (1) ◽

pp. 47-49

Author(s):

Jinghe Wang ◽

Miao Yu ◽

Zhichao Wu ◽

Yingchun Liang ◽

Shen Dong

Keyword(s):

Stress Relaxation ◽

Atomic Force Microscope ◽

Cancer Cells ◽

Atomic Force ◽

Relaxation Characteristics

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Flexible Multiscale Pore Hybrid Self-Powered Sensor for Heart Sound Detection

Sensors ◽

10.3390/s21134508 ◽

2021 ◽

Vol 21 (13) ◽

pp. 4508

Author(s):

Boyan Liu ◽

Liuyang Han ◽

Lyuming Pan ◽

Hongzheng Li ◽

Jingjing Zhao ◽

...

Keyword(s):

Piezoelectric Coefficient ◽

Heart Sound ◽

Piezoelectric Materials ◽

Ferroelectric Material ◽

Flexible Sensor ◽

Β Phase ◽

Short Processing Time ◽

Sound Detection ◽

Corona Poling ◽

Self Powered

This research introduces an idea of producing both nanoscale and microscale pores in piezoelectric material, and combining the properties of the molecular β-phase dipoles in ferroelectric material and the space charge dipoles in order to increase the sensitivity of the sensor and modulate the response frequency bandwidth of the material. Based on this idea, a bi-nano-micro porous dual ferro-electret hybrid self-powered flexible heart sound detection sensor is proposed. Acid etching and electrospinning were the fabrication processes used to produce a piezoelectric film with nanoscale and microscale pores, and corona poling was used for air ionization to produce an electret effect. In this paper, the manufacturing process of the sensor is introduced, and the effect of the porous structure and corona poling on improving the performance of the sensor is discussed. The proposed flexible sensor has an equivalent piezoelectric coefficient d33 of 3312 pC/N, which is much larger than the piezoelectric coefficient of the common piezoelectric materials. Experiments were carried out to verify the function of the flexible sensor together with the SS17L heart sound sensor (BIOPAC, Goleta, CA, USA) as a reference. The test results demonstrated its practical application for wearable heart sound detection and the potential for heart disease detection. The proposed flexible sensor in this paper could realize batch production, and has the advantages of flexibility, low production cost and a short processing time compared with the existing heart sound detection sensors.

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