ENHANCEMENT OF THE SURFACE DIELECTRIC AND PHOTODIELECTRIC PROPERTIES OF LOW DENSITY POLYETHYLENE BY ADDING EMODIN

In this paper, we report surface dielectric and photodielectric properties of low density polyethylene (LDPE)/Emodin composite. Emodin was extracted from Fallopia japonica plant. The composite was obtained from the xylene solution. Dielectric measurements were performed in the frequency range from 240 Hz to 4 kHz and the temperature range from 20 °C – 70 °C. Irradiations of the sample were applied before and during measurement with selected wavelengths from UV to the visible range. Surface dielectric conductance and susceptance of the LDPE/Emodin composite is higher then value of conductance and susceptance of pure LDPE. We found an increase, by one order of magnitude, in conductance and susceptance of the LDPE/Emodin composite with increase of measurement frequency. Furthermore, the surface conductance and susceptance increase due to UV radiation in mentioned temperature range, but during visible radiation at frequency 1 kHz (except in the case green LED lamp) we observed the enhance of conductance only at temperature range up to 50 °C.

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Effect of thermal prehistory on the mechanical properties of mixtures of polypropylene with low-density polyethylene in a broad temperature range

Polymer Science U S S R ◽

10.1016/0032-3950(85)90210-2 ◽

1985 ◽

Vol 27 (8) ◽

pp. 1891-1896

Author(s):

N.S. Yenikolopyan ◽

A.M. Khachatryan ◽

N.M. Styrikovich ◽

V.G. Nikol'skii ◽

A.S. Kechek'yan

Keyword(s):

Mechanical Properties ◽

Broad Temperature Range ◽

Low Density Polyethylene ◽

Low Density ◽

Temperature Range ◽

Thermal Prehistory

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Mechanical energy losses in commercial crosslinked low-density polyethylene in the temperature range between 200 and 400 K

Journal of Applied Polymer Science ◽

10.1002/app.47605 ◽

2019 ◽

Vol 136 (23) ◽

pp. 47605

Author(s):

Osvaldo Agustín Lambri ◽

Federico Guillermo Bonifacich ◽

José Ángel García ◽

Enrique David Victor Giordano ◽

Griselda Irene Zelada ◽

...

Keyword(s):

Mechanical Energy ◽

Low Density Polyethylene ◽

Energy Losses ◽

Low Density ◽

Temperature Range

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Influence of the Thermomechanical Characteristics of Low-Density Polyethylene Substrates on the Thermoresistive Properties of Graphite Nanoplatelet Coatings

Coatings ◽

10.3390/coatings11030332 ◽

2021 ◽

Vol 11 (3) ◽

pp. 332

Author(s):

Ubaldo Coscia ◽

Angela Longo ◽

Mariano Palomba ◽

Andrea Sorrentino ◽

Gianni Barucca ◽

...

Keyword(s):

Flexible Electronics ◽

Low Density Polyethylene ◽

Gauge Factor ◽

Low Density ◽

Graphite Nanoplatelets ◽

Electrical Measurements ◽

Scanning Calorimetry ◽

Coating Films ◽

Linear Temperature ◽

Temperature Range

Morphological, structural, and thermoresistive properties of films deposited on low-density polyethylene (LDPE) substrates are investigated for possible application in flexible electronics. Scanning and transmission electron microscopy analyses, and X-ray diffraction measurements show that the films consist of overlapped graphite nanoplatelets (GNP) each composed on average of 41 graphene layers. Differential scanning calorimetry and dynamic-mechanical-thermal analysis indicate that irreversible phase transitions and large variations of mechanical parameters in the polymer substrates can be avoided by limiting the temperature variations between −40 and 40 °C. Electrical measurements performed in such temperature range reveal that the resistance of GNP films on LDPE substrates increases as a function of the temperature, unlike the behavior of graphite-based materials in which the temperature coefficient of resistance is negative. The explanation is given by the strong influence of the thermal expansion properties of the LDPE substrates on the thermo-resistive features of GNP coating films. The results show that, narrowing the temperature range from 20 to 40 °C, the GNP on LDPE samples can work as temperature sensors having linear temperature-resistance relationship, while keeping constant the temperature and applying mechanical strains in the 0–4.2 × 10−3 range, they can operate as strain gauges with a gauge factor of about 48.

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Near-field scanning optical microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100144644 ◽

1986 ◽

Vol 44 ◽

pp. 642-643

Author(s):

E. Betzig ◽

A. Harootunian ◽

M. Isaacson ◽

A. Lewis

Keyword(s):

Near Field ◽

Optical Microscope ◽

Visible Radiation ◽

Field Methods ◽

Optical Elements ◽

Optical Region ◽

Order Of Magnitude ◽

Nondestructive Imaging ◽

Scanning Optical Microscopy ◽

Near Field Scanning

In general, conventional methods of optical imaging are limited in spatial resolution by either the wavelength of the radiation used or by the aberrations of the optical elements. This is true whether one uses a scanning probe or a fixed beam method. The reason for the wavelength limit of resolution is due to the far field methods of producing or detecting the radiation. If one resorts to restricting our probes to the near field optical region, then the possibility exists of obtaining spatial resolutions more than an order of magnitude smaller than the optical wavelength of the radiation used. In this paper, we will describe the principles underlying such "near field" imaging and present some preliminary results from a near field scanning optical microscope (NS0M) that uses visible radiation and is capable of resolutions comparable to an SEM. The advantage of such a technique is the possibility of completely nondestructive imaging in air at spatial resolutions of about 50nm.

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