PREDICTION OF FUNCTIONAL PARAMETERS FOR A NANOSTRUCTURED POLYMER-CERAMIC COATING ON THE BASIS OF ANODIC OXIDES OF METALS

Strength and strain sensitivity of a thin polymer-ceramic coating in the form of a nanoporous anodic aluminum oxide impregnated with a piezoelectric polymer are studied. The coating is considered as a unidirectionally reinforced composite containing cylindrical polymer fibers oriented perpendicular to the coating surface. A three-phase micromechanical model of the specified material is proposed and the stress-strain state of the coating under the influence of uniformly distributed pressure is analyzed. As a result of solving the related problem of electroelasticity, calculated estimates of the specific piezoelectric sensitivity of the coating used as a pressure sensor and the maximum allowable pressure were obtained according to the strength criteria of the ceramic matrix and the plastic flow of the polymer filler. The article shows dependences of the indicated parameters on the volumetric content of the polymer for the coating, adhesively bonded to a non-deformable foundation and freely (without friction) lying on the foundation. At low volume content of polymer, the strength loss of coating is caused by local failure of matrix. At high filler content the transition of polymer into plastic state precedes to the beginning of matrix failure. After increasing the filler content above 80 % the value of maximal pressure according to yield criteria for polymer filler scarcely changes.

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Catheters for Thrombosis Sample Exfoliation in Blood Vessels Using Piezoelectric Polymer Fibers

Biomedical Applications of Electroactive Polymer Actuators ◽

10.1002/9780470744697.ch18 ◽

2009 ◽

pp. 357-368

Author(s):

Yoshiro Tajitsu

Keyword(s):

Blood Vessels ◽

Polymer Fibers ◽

Piezoelectric Polymer

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Thermodynamic approach to tailor porosity in piezoelectric polymer fibers for application in nanogenerators

Nano Energy ◽

10.1016/j.nanoen.2019.05.044 ◽

2019 ◽

Vol 62 ◽

pp. 594-600 ◽

Cited By ~ 12

Author(s):

Mohammad Mahdi Abolhasani ◽

Minoo Naebe ◽

Kamyar Shirvanimoghaddam ◽

Hossein Fashandi ◽

Hamid Khayyam ◽

...

Keyword(s):

Polymer Fibers ◽

Thermodynamic Approach ◽

Piezoelectric Polymer

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Poling and characterization of piezoelectric polymer fibers for use in textile sensors

Sensors and Actuators A Physical ◽

10.1016/j.sna.2013.08.011 ◽

2013 ◽

Vol 201 ◽

pp. 477-486 ◽

Cited By ~ 70

Author(s):

Erik Nilsson ◽

Anja Lund ◽

Christian Jonasson ◽

Christer Johansson ◽

Bengt Hagström

Keyword(s):

Polymer Fibers ◽

Piezoelectric Polymer ◽

Textile Sensors

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Impact of Conducting Polymer Filler on the Dielectric Properties of Nylon 11

Chemistry & Chemical Technology ◽

10.23939/chcht03.01.047 ◽

2009 ◽

Vol 3 (1) ◽

pp. 47-51

Author(s):

Shilpa Pande ◽

◽

Deepali Kelkar ◽

Dilip Peshwe ◽

◽

...

Keyword(s):

Dielectric Properties ◽

Dielectric Permittivity ◽

Conducting Polymer ◽

High Frequency ◽

Filler Content ◽

Dissipation Factor ◽

Polymer Filler ◽

Wide Range ◽

Conducting Filler ◽

Nylon 11

The dielectric studies of semi-crystalline Nylon 11 filled with a conducting polymer (PANI) were investigated in a wide range of frequency and temperature by using Impedance Analyzer. The main focus was on the effects of conducting filler content on dielectric properties of Nylon 11. The prominent factors such as dielectric permittivity, loss factor, and loss tangent were studied at high frequency. Two different concentrations (1 % and 5 % w/w) of the conducting filler were used. It was observed that with the increase of fillers concentration, the value of dielectric permittivity (ε’)б The dissipation factor (ε’’) and loss (tan ) decrease compared to pure Nylon 11.

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Polarized microbeam FT-IR analysis of single fibers

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100163496 ◽

1996 ◽

Vol 54 ◽

pp. 206-207

Author(s):

Liling Cho ◽

David L. Wetzel

Keyword(s):

Molecular Orientation ◽

Transition Point ◽

Polymer Fibers ◽

Single Fiber ◽

Wire Grid ◽

Polyester Fibers ◽

Ft Ir ◽

Ir Analysis ◽

The Relationship ◽

Wire Grid Polarizer

Polarized infrared microscopy has been used for forensic purposes to differentiate among polymer fibers. Dichroism can be used to compare and discriminate between different polyester fibers, including those composed of polyethylene terephthalate that are frequently encountered during criminal casework. In the fiber manufacturering process, fibers are drawn to develop molecular orientation and crystallinity. Macromolecular chains are oriented with respect to the long axis of the fiber. It is desirable to determine the relationship between the molecular orientation and stretching properties. This is particularly useful on a single fiber basis. Polarized spectroscopic differences observed from a single fiber are proposed to reveal the extent of molecular orientation within that single fiber. In the work presented, we compared the dichroic ratio between unstretched and stretched polyester fibers, and the transition point between the two forms of the same fiber. These techniques were applied to different polyester fibers. A fiber stretching device was fabricated for use on the instrument (IRμs, Spectra-Tech) stage. Tension was applied with a micrometer screw until a “neck” was produced in the stretched fiber. Spectra were obtained from an area of 24×48 μm. A wire-grid polarizer was used between the source and the sample.

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Characterization of thermal barrier coatings formed by electon-beam physical vapor deposition (EB-PVD)

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010015410x ◽

1989 ◽

Vol 47 ◽

pp. 426-427

Author(s):

Ozer Unal

Keyword(s):

Thermal Barrier Coatings ◽

Physical Vapor Deposition ◽

Ceramic Coating ◽

High Vacuum ◽

Ceramic Coatings ◽

High Energy ◽

Thermal Barrier ◽

Protective Oxide ◽

Barrier Coatings ◽

Energy Beam

Interest in ceramics as thermal barrier coatings for hot components of turbine engines has increased rapidly over the last decade. The primary reason for this is the significant reduction in heat load and increased chemical inertness against corrosive species with the ceramic coating materials. Among other candidates, partially-stabilized zirconia is the focus of attention mainly because ot its low thermal conductivity and high thermal expansion coefficient.The coatings were made by Garrett Turbine Engine Company. Ni-base super-alloy was used as the substrate and later a bond-coating with high Al activity was formed over it. The ceramic coatings, with a thickness of about 50 μm, were formed by EB-PVD in a high-vacuum chamber by heating the target material (ZrO2-20 w/0 Y2O3) above its evaporation temperaturef >3500 °C) with a high-energy beam and condensing the resulting vapor onto a rotating heated substrate. A heat treatment in an oxidizing environment was performed later on to form a protective oxide layer to improve the adhesion between the ceramic coating and substrate. Bulk samples were studied by utilizing a Scintag diffractometer and a JEOL JXA-840 SEM; examinations of cross-sectional thin-films of the interface region were performed in a Philips CM 30 TEM operating at 300 kV and for chemical analysis a KEVEX X-ray spectrometer (EDS) was used.

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Structure characterization of ground calcium carbonate flocs by fractal analysis and their effects on handsheet properties

TAPPI Journal ◽

10.32964/tj12.3.17 ◽

2013 ◽

Vol 12 (3) ◽

pp. 17-23 ◽

Cited By ~ 3

Author(s):

WANHEE IM ◽

HAK LAE LEE ◽

HYE JUNG YOUN ◽

DONGIL SEO

Keyword(s):

Fractal Analysis ◽

Structural Characteristics ◽

Fractal Dimensions ◽

Strength Loss ◽

Structure Characterization ◽

Uniform Size ◽

Cross Sectional ◽

Floc Size ◽

Mass Fractal ◽

Handsheet Properties

Preflocculation of filler particles before their addition to pulp stock provides the most viable and practical solution to increase filler content while minimizing strength loss. The characteristics of filler flocs, such as floc size and structure, have a strong influence on preflocculation efficiency. The influence of flocculant systems on the structural characteristics of filler flocs was examined using a mass fractal analysis method. Mass fractal dimensions of filler flocs under high shear conditions were obtained using light diffraction spectroscopy for three different flocculants. A single polymer (C-PAM), a dual cationic polymer (p-DADMAC/C-PAM) and a C-PAM/micropolymer system were used as flocculants, and their effects on handsheet properties were investigated. The C-PAM/micropolymer system gave the greatest improvement in tensile index. The mass fractal analysis showed that this can be attributed to the formation of highly dense and spherical flocs by this flocculant. A cross-sectional analysis of the handsheets showed that filler flocs with more uniform size were formed when a C-PAM/micropolymer was used. The results suggest that a better understanding of the characteristics of preflocculated fillers and their influence on the properties of paper can be gained based on a fractal analysis.

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Upscaling of foam forming technology for pilot scale

TAPPI Journal ◽

10.32964/tj18.8.461 ◽

2019 ◽

Vol 18 (8) ◽

Cited By ~ 1

Author(s):

JANI LEHMONEN ◽

TIMO RANTANEN ◽

KARITA KINNUNEN-RAUDASKOSKI

Keyword(s):

Production Efficiency ◽

Strength Loss ◽

Pilot Scale ◽

Foam Density ◽

Forming Process ◽

Production Scale ◽

Forming Technology ◽

Wet Pressing ◽

Foam Forming ◽

Board Industry

The need for production cost savings and changes in the global paper and board industry during recent years have been constants. Changes in the global paper and board industry during past years have increased the need for more cost-efficient processes and production technologies. It is known that in paper and board production, foam typically leads to problems in the process rather than improvements in production efficiency. Foam forming technology, where foam is used as a carrier phase and a flowing medium, exploits the properties of dispersive foam. In this study, the possibility of applying foam forming technology to paper applications was investigated using a pilot scale paper forming environment modified for foam forming from conventional water forming. According to the results, the shape of jet-to-wire ratios was the same in both forming methods, but in the case of foam forming, the achieved scale of jet-to-wire ratio and MD/CD-ratio were wider and not behaving sensitively to shear changes in the forming section as a water forming process would. This kind of behavior would be beneficial when upscaling foam technology to the production scale. The dryness results after the forming section indicated the improvement in dewatering, especially when foam density was at the lowest level (i.e., air content was at the highest level). In addition, the dryness results after the pressing section indicated a faster increase in the dryness level as a function of foam density, with all density levels compared to the corresponding water formed sheets. According to the study, the bonding level of water- and foam-laid structures were at the same level when the highest wet pressing value was applied. The results of the study show that the strength loss often associated with foam forming can be compensated for successfully through wet pressing.

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Starch-modified fillers for linerboard and paper grades: A perspective review

TAPPI Journal ◽

10.32964/tj9.4.31 ◽

2010 ◽

Vol 9 (4) ◽

pp. 31-36 ◽

Cited By ~ 11

Author(s):

YULIN DENG ◽

PHIL JONES ◽

LESLIE MCLAIN ◽

ART J. RAGAUSKAS

Keyword(s):

Filler Content ◽

Product Platform ◽

Laboratory Studies ◽

The Past ◽

Development Opportunity ◽

Laboratory Results ◽

Addition Rate ◽

Institute Of Technology ◽

Paper Product ◽

Detrimental Impact

High-filler-content paper is a growing research and development opportunity in papermaking. These new products must address traditional paper product properties while providing papermakers with distinct product platform benefits. Over the past decade, a research team involving researchers from the Institute of Paper Science and Technology at Georgia Institute of Technology and from Imerys have significantly advanced the application of starch-encapsulated papermaking fillers. This review summarizes these accomplishments from initial laboratory studies to mill trials. Laboratory results have illustrated that starch-encapsulated fillers can facilitate a near-doubling of filler content over conventional levels at equal tensile and z-direction tensile (ZDT) values. Equally important is that the use of starch-encapsulated kaolin (SEK) filler has been shown to facilitate a doubling of filler addition rate without any detrimental impact on ring crush compared with control studies with filler. Pilot-plant and mill trials have shown that SEK can function as a fiber extender, reduce steam demand for drying by 10%, and increase papermaking speeds and production rates.

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