Relevant bibliographies by topics / Polymeric Powders / Journal articles

Journal articles on the topic 'Polymeric Powders'

To see the other types of publications on this topic, follow the link: Polymeric Powders.
Author: Grafiati
Published: 10 December 2022
Last updated: 28 January 2023

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 journal articles for your research on the topic 'Polymeric Powders.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.

1

Вернигоров, Юрий, Yuriy Vernigorov, Валерий Лебедев, Valeriy Lebedev, Кирилл Лелетко, Kirill Leletko, Андрей Ширин, and Andrey Shirin. "Science intensive technology for manufacturing composite powders in magnetic vibrating layer." Science intensive technologies in mechanical engineering 2019, no. 5 (May 19, 2019): 3–8. http://dx.doi.org/10.30987/article_5ca303087cba57.59333232.

Full text
Abstract:
The paper reports the analysis of a problem current state connected with manufacturing high-quality composite powders. There is offered a device which allows obtaining a high uniformity of alloy addition distribution under conditions of a magnetic vibrating layer, and also metal polymeric composite powders. A designed model allowing the definition of a gradient interval of magnetic field induction is obtained, at which powder cluster destruction takes place and powder stable magnetic boiling is supported.
APA, Harvard, Vancouver, ISO, and other styles
2

Iwamoto, Yuji, Ko-ichi Kikuta, and Shin-ichi Hirano. "Microstructural development of Si3N4–SiC–Y2O3 ceramics derived from polymeric precursors." Journal of Materials Research 13, no. 2 (February 1998): 353–61. http://dx.doi.org/10.1557/jmr.1998.0047.

Full text
Abstract:
[Si–Y–O–C–N] amorphous powders were synthesized by the pyrolysis at 1000 °C in N2 of chemically modified perhydropolysilazane using n-decyl alcohol and yttrium tri-methoxide. [Si–Y–O–C–N] amorphous powders yielded a unique fibrous microstructure by heat treatment in N2 at 1800 °C. The fibrous microstructure was composed of β–Si3N4 whiskers of submicron in diameter and more than 10 μm in length. Fully dense Si3N4 –SiC–Y2O3 ceramics were also fabricated by heat treatment at 1800 °C followed by powder-vehicle hot pressing at 1700 °C. After these two-step processings, [Si–Y–O–C–N] amorphous powders yielded a unique fine-grained microstructure composed of submicron grains with high aspect ratio.
APA, Harvard, Vancouver, ISO, and other styles
3

Park, Tae-Min, Choong-Hwan Jung, Haejin Hwang, and Sang-Jin Lee. "Polymer Solution Route for Synthesis of Nano-Sized, SiO2 Based Ceramic Powders." Journal of Nanoscience and Nanotechnology 20, no. 7 (July 1, 2020): 4498–501. http://dx.doi.org/10.1166/jnn.2020.17568.

Full text
Abstract:
Nano-sized SiO2 based powders were fabricated by a polymer solution technique. Nitrate metal sources and Ludox series silica sol were dissolved in D.I. water and then polyvinyl alcohol solution was added as a polymeric carrier. The metal cations were dispersed well in the solution and a homogeneous polymeric network was formed. The organic–inorganic precursor gels were turned to a porous powder with expanded volume through an explosive oxidation reaction during calcination process. The polymer molecular weight, polymer content and heating rate affected the particle agglomeration and size. The reaction between oxygen and unstable metal cations resulted in a vigorous exothermic reaction and simultaneously the reaction created extensive voids, which accompanied soft powders. The porous powders were crystallized at relatively lower temperature, and easily ground to a very fine powder having nano-sized particles. The crystalline development was also dependent on the polymer type, and the weak hydrogen bonding by optimum polymer content promoted homogeneous entrapment between the –(OH) hydroxyl groups and cations, which are solvates by water molecules.
APA, Harvard, Vancouver, ISO, and other styles
4

Naqshbandi, Abreeq, Iis Sopyan, Gunawan, and Suryanto. "Sol-Gel Synthesis of Zn Doped HA Powders and their Conversion to Porous Bodies." Applied Mechanics and Materials 493 (January 2014): 603–8. http://dx.doi.org/10.4028/www.scientific.net/amm.493.603.

Full text
Abstract:
The present study was aimed at fabricating porous ceramic scaffolds via polymeric sponge method for biomedical applications using as synthesized Zinc doped Hydroxyapatite (ZnHA) powders. Zn doped HA powders were prepared via sol-gel method using diammonia hydrogen phosphate [(NH4)2HPO4] and calcium nitrate tetrahydrate [Ca (NO3)2.4H2 as starting materials. The obtained powders were then used for the preparation of porous ZnHA scaffolds via polymeric sponge method. The green porous bodies so developed by impregnating cellulosic sponges with HA slurries, were subjected to sintering process at a temperature of 1300 Field-emission scanning electron microscopy (FESEM) was used to observe the surface morphology of the powder and sintered porous sample. The structure and crystallinity of (Zn)HA powder and the sintered porous samples was analyzed using X-ray diffractometer whereas Fourier transform infrared spectroscopy (FTIR) was used to determine the presence of various phases in the powder. FESEM results showed the formation of agglomerates at an increased Zn concentration. The morphology of the porous samples showed high degree of fusion and densification with an increase in Zn concentration. Preliminary mechanical testing results show that maximum compression strength of HA porous bodies was 0.12 MPa.
APA, Harvard, Vancouver, ISO, and other styles
5

Brink, A. E., K. J. Jordens, and J. S. Riffle. "Sintering high performance semicrystalline polymeric powders." Polymer Engineering and Science 35, no. 24 (December 1995): 1923–30. http://dx.doi.org/10.1002/pen.760352403.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Costa, G. C. C. da, and R. Muccillo. "Synthesis of Lanthanum Beta Alumina by the Polymeric Precursor Technique." Materials Science Forum 530-531 (November 2006): 649–54. http://dx.doi.org/10.4028/www.scientific.net/msf.530-531.649.

Full text
Abstract:
Lanthanum beta alumina powders were obtained by the polymeric precursor technique using lanthanum nitrate, aluminum nitrate, ethylene glycol and citric acid. The transformations that occur during thermal treatment of the precursor solution were evaluated by thermogravimetric and differential thermal analysis. Fourier Transform Infrared analysis for residual carbon qualitative detection and gas adsorption analysis for evaluating specific surface area, BET method, were carried out in powder specimens heat treated at different temperatures. High calcination temperature leads to the formation of hard agglomerates. The powders calcined at 800°C for 4 h have high specific surface area, ~ 120 m2/g. All processed powders and green pellets sintered at different temperatures were analyzed by X-ray diffraction for structural phase determination. Single phase LaAl11O18 pellets have application as solid electrolytes in disposable electrochemical devices for monitoring dissolved oxygen species in molten steel at very high temperatures, > 1500 °C, during steel production.
APA, Harvard, Vancouver, ISO, and other styles
7

Mwania, Fredrick M., Maina Maringa, and Kobus van der Walt. "A Review of Methods Used to Reduce the Effects of High Temperature Associated with Polyamide 12 and Polypropylene Laser Sintering." Advances in Polymer Technology 2020 (August 4, 2020): 1–11. http://dx.doi.org/10.1155/2020/9497158.

Full text
Abstract:
The polymer laser sintering (PLS) process is one of the most promising additive manufacturing (AM) technologies for polymeric materials. However, the technique has challenges because the physical, mechanical, and chemical properties of the polymeric powder deteriorate due to the high temperatures prevailing in the build chamber during manufacture. These high temperatures cause agglomeration of powder, which leads to a decrease in the flowability of powder. There is also a related drop in the coalescence of the powder granules during PLS, which results in porosity that undermines the mechanical integrity of printed parts. Moreover, the viscosity of the melt increases due to cross-linking of molecular chains. This, in turn, increases the tensile strength of the printed components at the expense of the percentage elongation at break. Thus, high prolonged processing temperatures decrease the reusability of polymeric materials used in PLS. In this paper, a review of the studies conducted to investigate ways of reducing the effects of high temperature on polymeric powders is presented.
APA, Harvard, Vancouver, ISO, and other styles
8

Mwania, Fredrick Mulinge, Maina Maringa, and Jacobus G. van der Walt. "A review of the techniques used to characterize laser sintering of polymeric powders for use and re-use in additive manufacturing." Manufacturing Review 8 (2021): 14. http://dx.doi.org/10.1051/mfreview/2021012.

Full text
Abstract:
Additive manufacturing (AM), is one of the key components of the 4th industrial revolution. Polymer laser sintering (PLS) is a subset of AM that is commonly used to process polymers, and which achieves good surface finish, good mechanical properties of finished products and for which there is no need for support structures. However, the requirements for polymeric powder for PLS are strident. Moreover, PLS subjects polymeric feed powders to high temperatures that lead to degradation of their thermal, rheological, and physical properties and is thus an impediment to their recyclability. Therefore, it is imperative to investigate the degree of polymer degradation or aging before re-using the material. This paper reviews the common techniques that are employed to characterize the suitability of polymeric powders for use and re-use in the PLS process. These include, but are not limited to, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), laser diffraction analysis, gas pycnometry, scanning electron microscopy (SEM), and melt flow index (MFI) testing.
APA, Harvard, Vancouver, ISO, and other styles
9

Lee, Sang Jin, Chung Hyo Lee, and S. Y. Chun. "Organic-Inorganic Solution Technique for Fabrication of Porous CaO-SiO2 Based Powders." Key Engineering Materials 287 (June 2005): 117–22. http://dx.doi.org/10.4028/www.scientific.net/kem.287.117.

Full text
Abstract:
Soft and porous CaO-SiO2 powders (CaSiO3, Ca2SiO4, Ca3SiO5) were fabricated by organic-inorganic solution technique. Calcium nitrate and Ludox SK silica sol were dissolved in D.I. water and then 5 wt% polyvinyl alcohol solution was added as a polymeric carrier. The metal cations were dispersed well in solution and a homogeneous polymeric network was formed. The organic-inorganic precursor gels were turned to porous powder having volume expansion through an explosive oxidation reaction during calcination process. The polyvinyl alcohol content and heating rate were affected on the explosive reaction behavior. It may be speculated that the reaction between oxygen and unstable calcium cations resulted in the vigorous exothermic reaction and simultaneously the reaction made extensive void, which is accompanied with volume expansion in the powder structure, by the thermal decomposition in a moment of organic substance, polyvinyl alcohol. The porous powders were crystallized at relatively lower temperatures, and the crystalline development was dependent on the polymer content.
APA, Harvard, Vancouver, ISO, and other styles
10

Put, S., C. Bertels, and A. Vanhulsel. "Atmospheric pressure plasma treatment of polymeric powders." Surface and Coatings Technology 234 (November 2013): 76–81. http://dx.doi.org/10.1016/j.surfcoat.2013.02.006.

Full text
APA, Harvard, Vancouver, ISO, and other styles
11

Lee, Biing-Lin. "Thermo-mechanical test methods for polymeric powders." Powder Technology 63, no. 1 (October 1990): 97–101. http://dx.doi.org/10.1016/0032-5910(90)80012-n.

Full text
APA, Harvard, Vancouver, ISO, and other styles
12

Qiu, X., A. K. Datye, T. T. Borek, and R. T. Paine. "Development of Crystallinity in Turbostratic Boron Nitride Derived from Polymeric Precursors." Proceedings, annual meeting, Electron Microscopy Society of America 49 (August 1991): 954–55. http://dx.doi.org/10.1017/s0424820100089081.

Full text
Abstract:
Boron nitride derived from polymer precursors is of great interest for applications such as fibers, coatings and novel forms such as aerogels. The BN is prepared by the polymerization of functionalized borazine and thermal treatment in nitrogen at 1200°C. The BN powders obtained by this route are invariably trubostratic wherein the sheets of hexagonal BN are randomly oriented to yield the so-called turbostratic modification. Fib 1a and 1b show images of BN powder with the corresponding diffraction pattern in fig. 1c. The (0002) reflection from BN is seen as a diffuse ring with occational spots that come from crystals of BN such as those shown in fig. 1b. The (0002) lattice fringes of BN seen in these powders are the most characteristic indication of the crystallinity of the BN.
APA, Harvard, Vancouver, ISO, and other styles
13

da Silva, Margarete Soares, Alberto A. Cavalheiro, Maria Aparecida Zaghete, Mário Cilense, Guilhermina F. Teixeira, Gustavo F. Cavenago, Rafael Gomes Dias, and Lucas L. Silva. "Parameters Optimization of Heat Treatment for Obtaining Luminescent PZT Powders." Materials Science Forum 805 (September 2014): 519–24. http://dx.doi.org/10.4028/www.scientific.net/msf.805.519.

Full text
Abstract:
Low crystalline PZT powder samples were successfully synthesized using polymeric precursor method and slow decomposition steps. The polymeric resin precursor was thermal treated in a muffle type oven varying the temperature from 250 °C to 700 °C and the time from 3 to 24 hours in order to investigate the order/disorder mechanism toward the amorphous powders. Powder samples with low crystalline phases were obtained at lower temperatures and long time of thermal treatment, demonstrating a kinetic dependence for organic removal and a thermodynamic barrier for crystallization processes. Through XRD and FTIR spectroscopy characterizations the long time thermal treated samples showed to be composed of the solid solution of metal oxides in absent of organic matter, originating broad XRD peaks profiles and no carbonaceous bands in FTIR spectra. A Photoluminescence characterization showed that the peak emission is higher for disordered and homogeneous phases, which only can be reached through the long time of thermal treatment.
APA, Harvard, Vancouver, ISO, and other styles
14

Ecker, J. V., K. Dobrezberger, J. Gonzalez-Gutierrez, M. Spoerk, Ch Gierl-Mayer, and H. Danninger. "Additive Manufacturing of Steel and Copper Using Fused Layer Modelling: Material and Process Development." Powder Metallurgy Progress 19, no. 2 (December 1, 2019): 63–81. http://dx.doi.org/10.1515/pmp-2019-0007.

Full text
Abstract:
AbstractFused Layer Modelling (FLM) is one out of several material extrusion (ME) additive manufacturing (AM) methods. FLM usually deals with processing of polymeric materials but can also be used to process metal-filled polymeric systems to produce metallic parts. Using FLM for this purpose helps to save costs since the FLM hardware is cheap compared to e.g. direct metal laser processing hardware, and FLM offers an alternative route to the production of metallic components.To produce metallic parts by FLM, the methodology is different from direct metal processing technologies, and several processing steps are required: First, filaments consisting of a special polymer-metal composition are produced. The filament is then transformed into shaped parts by using FLM process technology. Subsequently the polymeric binder is removed (”debinding”) and finally the metallic powder body is sintered. Depending on the metal powder used, the binder composition, the FLM production parameters and also the debinding and sintering processes must be carefully adapted and optimized.The focal points of this study are as following:1. To confirm that metallic parts can be produced by using FLM plus debinding and sintering as an alternative route to direct metal additive manufacturing.2. Determination of process parameters, depending on the used metal powders (steel and copper) and optimization of each process step.3. Comparison of the production paths for the different metal powders and their debinding and sintering behavior as well as the final properties of the produced parts.The results showed that both materials were printable after adjusting the FLM parameters, metallic parts being produced for both metal powder systems. The production method and the sintering process worked out well for both powders. However there are specific challenges in the sintering process that have to be overcome to produce high quality metal parts. This study serves as a fundamental basis for understanding when it comes to the processing of steel and copper powder into metallic parts using FLM processing technology.
APA, Harvard, Vancouver, ISO, and other styles
15

Tao, Xue Yu, Wen Feng Qiu, and Hao Li. "Synthesis of Nanosized Zirconium Carbide (ZrC) by a Polymeric Precursor Route." Advanced Materials Research 393-395 (November 2011): 373–76. http://dx.doi.org/10.4028/www.scientific.net/amr.393-395.373.

Full text
Abstract:
Based on the basic principle of carbothermal reduction reactions in the ZrO2-C system, nanosized ZrC powders were synthesized by the preceramic method using Polyzirconoxane (PZO) and salicyl alcohol (SA) as sources of zirconia and carbon respectively. The obtained polymeric precursor exhibited excellent solubility and rheology for the processing of ceramic matrix composites. Thermal dynamic change process, phase composition, crystallite size and morphology of the synthesized powders were characterized by Thermogravimetric analysis (TGA)、 Scanning electron microscopy (SEM) and X-ray powder diffraction (XRD). When heat-treated at 900 °C under flowing argon, precursors transformed into intimately mixed amorphous carbon and nanosized tetragonal ZrO2. Further heat treatments (1300 °C) led to the formation of zirconium carbide with a yield of 70.6 %. The obtained ZrC particles exhibit cubic morphology with size ranged in 50-100 nm. This study displays the preparation of nanosized ZrC materials from the preceramic polymers.
APA, Harvard, Vancouver, ISO, and other styles
16

Prado, Fabíola Stahlke, Tânia Cristina Simões, and Alejandra Hortencia Miranda González. "Synthesis and characterization of an experimental 3Y-TZP dental ceramic prepared by polymeric precursors method." Research, Society and Development 9, no. 10 (October 18, 2020): e7919109123. http://dx.doi.org/10.33448/rsd-v9i10.9123.

Full text
Abstract:
The aim of the investigation was to synthesize 3 mol% yttria-stabilized zirconia (3Y-TZP) powders via polymeric precursor method (PPM). The precursor solution was preheated at 350ºC for 3h, subsequently thermally treated at 500ºC for 3h and 800ºC for 6h. The obtained materials were analyzed by Thermogravimetry-Derivative Thermogravimetry (TG/DTG), Differential Thermal Analysis (DTA), powder X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). Two commercially available Y-TZP ceramic systems were chosen for comparison. XRD analysis of the synthesized 3Y-TZP powders revealed the crystallization of the tetragonal phase, while both commercial systems showed the coexistence of the monoclinic and tetragonal phases. SEM analysis showed that the powders thermally treated at 800°C consist of agglomerated spherical nanoparticles. Morphology of commercial systems also revealed nanosized spherical particles. Results revealed that the PPM led to ceramics with structural and morphological properties comparable to commercially available reinforced dental ceramics.
APA, Harvard, Vancouver, ISO, and other styles
17

Brink, A. E., S. Gutzeit, T. Lin, H. Marand, K. Lyon, T. Hua, R. Davis, and J. S. Riffle. "Fine polymeric powders from poly(aryleneether ketone)s." Polymer 34, no. 4 (February 1993): 825–29. http://dx.doi.org/10.1016/0032-3861(93)90369-l.

Full text
APA, Harvard, Vancouver, ISO, and other styles
18

Vijatovic, Mirjana, Milos Vasic, Jelena Bobic, Ljiljana Zivkovic, and Biljana Stojanovic. "Effect of powder synthesis method on BaTiO3 ceramics." Processing and Application of Ceramics 2, no. 1 (2008): 27–31. http://dx.doi.org/10.2298/pac0801027v.

Full text
Abstract:
Barium titanate (BaTiO3) has been of practical interest for more than 60 years because of its attractive properties. BaTiO3 can be prepared using different methods, which can have significant influence on the structure and properties of barium titanate ceramics. In this paper powder of BaTiO3 powders were prepared by two methods. The first was synthesis from polymeric precursors through Pechini process which was carried out as a three-stage process from an oganometallic complex, producing cubic BaTiO3 powders with 40-80 nm primary particles. The second was a mechanochemical synthesis from powder mixture of BaO and TiO2, producing cubic BaTiO3 but with primary particles 200-250 nm. In both cases BaTiO3 ceramics were produced by sintering for 2h at 1300?C without a pre-calcination step. The phases formed and the crystal structure of BaTiO3 prepared by both methods was carried out by XRD analysis. The morphology and microstructure of obtained powders and sintered samples were examined by SEM.
APA, Harvard, Vancouver, ISO, and other styles
19

Muccillo, R., and J. R. Carmo. "Synthesis and Characterization of Strontium and Calcium Titanate Polycrystalline Powders by a Modified Polymeric Precursor Technique." Materials Science Forum 727-728 (August 2012): 904–8. http://dx.doi.org/10.4028/www.scientific.net/msf.727-728.904.

Full text
Abstract:
SrTi0,65Fe0,35O3-δ, Ca0,5Sr0,5Ti0,65Fe0,35O3-δ, CaTi0,65Fe0,35O3-δceramic powders were synthesized by the polymeric precursor technique using CaCO3, SrCO3, C12H28O4Ti and Fe (NO3)3.9H2O. After calcination, each powder was heat treated at temperatures chosen according to data collected on thermogravimetric-differential thermal analysis experiments. The compositions were analyzed by X-ray diffraction for structural phase evaluation (either perovskite cubic or orthorhombic), laser scattering for determination of particle size distribution and average particle size, transmission electron microscopy (TEM) for observation of particle shape and average true size. Pressed powders sintered at 1250°C were analyzed by X-ray diffraction and X-ray fluorescence; their surfaces were observed by scanning probe microscopy (SPM) for topographical analysis of grains and grain boundaries. TEM results show that the powders consist of agglomerated nanoparticles. Sr-based compounds have cubic perovskite phases whereas Ca-based compounds are orthorhombic. SPM images show intergranular features which might be responsible for reported blocking of charge carriers observed in impedance spectroscopy diagrams.
APA, Harvard, Vancouver, ISO, and other styles
20

Wieczorek, Jakub, Agata Blacha-Grzechnik, Jerzy Łabaj, and Grzegorz Siwiec. "Tribological Properties of Polymer Composites Reinforced with Silver Particles." Advanced Materials Research 1036 (October 2014): 65–70. http://dx.doi.org/10.4028/www.scientific.net/amr.1036.65.

Full text
Abstract:
The paper presents results of investigations on a potential for utilisation of waste materials, containing silver powders, ceramics and polymer, for production of PTFE-matrix composites. The waste is a mix of Ag powders (10 – 15%), SiC and Al2O3 powders (20 – 50%) and polymeric powders (20 –50%). For composite production, high-temperature press moulding method was applied. Reinforcing materials and the matrix powder were mixed and subjected to the pressing process in a graphite mould at 350oC. Composite specimens containing 25% Ag, 50% Ag and 75% Ag were obtained. For the obtained composites, density, HB hardness and a friction coefficient were determined. The friction coefficient was evaluated in the “pin-on-block” test with the sliding distance of 2500 m and a load of 25 N with no lubrication. Wear of the composites was assessed based on a profilometry analysis. The obtained results suggest that the composites may be applied for manufacturing of components resistant to abrasive wear with a required, low friction coefficient.
APA, Harvard, Vancouver, ISO, and other styles
21

Liang, Bing Liang, Xing Hua Zheng, De Ping Tang, and Yun Long Ai. "Synthesis and Characterization of Ln(Mg0.5Ti0.5)O3 (Ln=La, Nd, Sm) Obtained by the Polymeric Precursor Method." Advanced Materials Research 335-336 (September 2011): 940–43. http://dx.doi.org/10.4028/www.scientific.net/amr.335-336.940.

Full text
Abstract:
Ln(Mg0.5Ti0.5)O3 (Ln=La, Nd, Sm) powders were prepared by polymeric precursor method. After calcined at the temperature range of 600 °C to 1300 °C, the powders were characterized by XRD, SEM and FT-IR. The results indicated that Ln(Mg0.5Ti0.5)O3 perovskite crystal phases were formed when the precursor powders were calcined at 800 °C and the crystallization of Ln(Mg0.5Ti0.5)O3 powders increased gradually with the increasing calcining temperature.
APA, Harvard, Vancouver, ISO, and other styles
22

WÖHRLE, D., R. BENTERS, O. SUVOROVA, G. SCHNURPFEIL, N. TROMBACH, and T. BOGDAHN-RAI. "Syntheses of structurally uniform polymeric phthalocyanines." Journal of Porphyrins and Phthalocyanines 04, no. 05 (August 2000): 491–97. http://dx.doi.org/10.1002/1099-1409(200008)4:5<491::aid-jpp265>3.0.co;2-6.

Full text
Abstract:
Very few papers describe the synthesis of structurally uniform polymeric phthalocyanines. Owing to their insolubility, it is difficult to get information on the structural uniformity, kind of end groups and molecular weight. The reaction conditions are severe to get well-defined polymeric phthalocyanines. In this paper, four methods are described to get pure polymeric phthalocyanines as powders by bulk or solution reactions and as thin films or coatings on carriers.
APA, Harvard, Vancouver, ISO, and other styles
23

Mineiro, Sergio Luiz, Maria do Carmo de Andrade Nono, and Carlos Kuranaga. "Sintering Properties of ZrO2 - 3 Mol % Y2O3 Obtained from Mixture of Nano and Microcrystalline Powders." Materials Science Forum 530-531 (November 2006): 456–60. http://dx.doi.org/10.4028/www.scientific.net/msf.530-531.456.

Full text
Abstract:
The polymeric precursor route based on the Pechini process was used to prepare a mixture of nano and microcrystalline powders. The zirconia powder was stabilized with 3 mol% of yttria. Powder characteristics were evaluated by the BET technique determined the specific area and the BJH method supplied the pore size distribution. The X-ray diffraction results and SEM observations were carried out to characterize both the powder mixture and the microstructures of the ceramic bodies. The sintering behavior shown in this work was studied by dilatometric experiment, being considered the shrinkage rate and densification of the microstructure.
APA, Harvard, Vancouver, ISO, and other styles
24

Berretta, S., O. Ghita, and K. E. Evans. "Morphology of polymeric powders in Laser Sintering (LS): From Polyamide to new PEEK powders." European Polymer Journal 59 (October 2014): 218–29. http://dx.doi.org/10.1016/j.eurpolymj.2014.08.004.

Full text
APA, Harvard, Vancouver, ISO, and other styles
25

Nascimento, G. C., D. M. Cechinel, R. Piletti, Erlon Mendes, M. M. S. Paula, Humberto Gracher Riella, and M. A. Fiori. "Effect of Different Concentrations and Sizes of Particles of Rice Husk Ash - RHS in the Mechanical Properties of Polypropylene." Materials Science Forum 660-661 (October 2010): 23–28. http://dx.doi.org/10.4028/www.scientific.net/msf.660-661.23.

Full text
Abstract:
The minerals powders are much applied on polymeric materials to better its properties and to promote new applications. The rice husk ash powder - RHS is a mineral compound has been applied on polymeric compounds to increase the stiffness. This work presents studies of different sizes of particles of RHS applied at different concentrations in polypropylene. To study the mechanical properties were applied techniques of Charpy Impact Resistance and Uniaxial Tensile Analysis. The morphology was observed using the optical microscope. The results showed that the CCA may be an alternative in the incorporation of mineral loads in polypropylene, since this is a waste product generated in the production of rice, thus the complete closure of the production cycle of the cereal.
APA, Harvard, Vancouver, ISO, and other styles
26

Cavalheiro, A. A., Juliana C. Bruno, M. A. Zaghete, and José Arana Varela. "Physical Characterization of K-Doped 0.9PMN-0.1PT Synthesized by an Association of the Columbite Route and the Polymeric Precursor Method." Materials Science Forum 498-499 (November 2005): 669–75. http://dx.doi.org/10.4028/www.scientific.net/msf.498-499.669.

Full text
Abstract:
The solid solution 0.9PbMg1/3Nb2/3O3-0.1PbTiO3 is one of the most widely investigated relaxor ceramic, because of its high dielectric constant and low sintering temperatures. PMN-PT powders containing single perovskite phase were prepared by using a Ti-modified columbite precursor obtained by the polymeric precursor method. Such precursor reacts directly with stoichiometric amount of PbO to obtain pyrochlore-free PMNPT powders. The structural effects of K additive included in the columbite precursor and 0.9PMN-0.1PT powders were also studied. The phase formation at each processing step was verified by XRD analysis, being these results used for the structural refinement by the Rietveld method. It was verified the addition of K in the columbite precursor promotes a slight increasing in the powder crystallinity. There was not a decrease in the amount of perovskite phase PMN-PT for 1mol% of K, and the particle and grain size were reduced, making this additive a powerful tool for grain size control.
APA, Harvard, Vancouver, ISO, and other styles
27

Thongsamrit, Wannisa, Thanida Charoensuk, Panissa Saetang, Pongsakorn Jantaratana, Chesta Ruttanapun, and Chitnarong Sirisathitkul. "Effects of Carbon Doping and Annealing Temperature on Magnetic MnAl Powders and MnAl Polymeric Composites." Applied Sciences 11, no. 5 (February 26, 2021): 2067. http://dx.doi.org/10.3390/app11052067.

Full text
Abstract:
Process parameters leading to magnetic polymer composites, an essential ingredient in the additive manufacturing of rare-earth-free magnets, are investigated. The induction melting of manganese (Mn) and aluminum (Al), and subsequent annealing at 450, 500, or 550 °C for 20 min, gave rise to ferromagnetic τ–MnAl phase, as well as other phases. The nonmagnetic Al4C3 and oxide phases were then removed by the magnetic separation. Magnetic powders from the magnetic separation were incorporated in polylactic acid (PLA) matrix via a solution route. The remanent magnetization as high as 4.3 emu/g in the powder form was reduced to 2.3–2.6 emu/g in the composites. The reduction in coercivity was minimal, and the largest value of 814 Oe was obtained when the powder annealed at 450 °C was loaded in the composite. The phase composition and hence magnetic properties were even more sensitive to the carbon (C) doping. Interestingly, the addition of 3% C led to coercivity as high as 1445 Oe in MnAl–C powders without further annealing. The enhanced coercivity was attributed to the domain wall pinning by the AlMn3C phase, and magnetizations are likely increased by this phase.
APA, Harvard, Vancouver, ISO, and other styles
28

Tai, Lone-Wen, and Paul A. Lessing. "Modified resin–intermediate processing of perovskite powders: Part I. Optimization of polymeric precursors." Journal of Materials Research 7, no. 2 (February 1992): 502–10. http://dx.doi.org/10.1557/jmr.1992.0502.

Full text
Abstract:
The formation of a polyester between citric acid (CA) and ethylene glycol (EG) was found to be a decisive factor for the foaming of resin intermediates in a Pechini-type powder process. This process was modified by changing the organic mass ratio of CA/EG which results in ceramic powders with different morphologies. The most porous resin intermediate (with or without chelated cations) was prepared using a polymeric gel made of equimolar citric acid and ethylene glycol. It was also found that a premixing of organic components, prior to adding constituent nitrate solutions, makes the whole process more controllable.
APA, Harvard, Vancouver, ISO, and other styles
29

Arzhakov, M. S., and S. A. Arzhakov. "Physical and Mechanical Behavior of Polymer Glasses: Polymeric Powders." International Journal of Polymeric Materials 40, no. 1-2 (April 1998): 1–16. http://dx.doi.org/10.1080/00914039808050138.

Full text
APA, Harvard, Vancouver, ISO, and other styles
30

Ruggi, David, Marco Lupo, Daniele Sofia, Claire Barrès, Diego Barletta, and Massimo Poletto. "Flow properties of polymeric powders for selective laser sintering." Powder Technology 370 (June 2020): 288–97. http://dx.doi.org/10.1016/j.powtec.2020.05.069.

Full text
APA, Harvard, Vancouver, ISO, and other styles
31

Li, Jiamao, and Tai Qiu. "Synthesis of SmAlO3 nanocrystalline powders by polymeric precursor method." Applied Physics A 104, no. 1 (January 26, 2011): 465–69. http://dx.doi.org/10.1007/s00339-011-6263-x.

Full text
APA, Harvard, Vancouver, ISO, and other styles
32

Barbosa, Graciele Vieira, Sabrina Vitor Gonçalves, Creuza Kimito Caceres Kawahara, Rafael Aparecido Ciola Amoresi, Margarete Soares da Silva, Jusinei Meireles Stropa, Lincoln Carlos Silva de Oliveira, and Alberto Adriano Cavalheiro. "Phase Formation in Copper and Calcium Titanate Dielectric Ceramic Obtained by Polymeric Precursor Method." Materials Science Forum 930 (September 2018): 20–25. http://dx.doi.org/10.4028/www.scientific.net/msf.930.20.

Full text
Abstract:
The polycrystalline ceramic named calcium and copper titanate is a dielectric ceramic with very high dielectric constant applicable in several electronic devices. The powder form for that advanced ceramic can be synthesized through chemical route, like the Polymeric Precursor Method at relative lower temperatures the presence of alkaline earth cations harms the structural homogenization during the crystallization process. In this work, the calcium and copper titanate powder was obtained by Polymeric Precursors Method by imposing a slow thermal decomposition of polymeric precursor and several crushing steps before the calcination at 800 °C for 4 hours. The entire process was observed by thermogravimetric analysis and FTIR spectrometry, including the nitrogen adsorption-desorption isotherms and X-ray diffractometry techniques for calcined power samples. It was observed the crystallization of the cubic Im-3 Ca1/4Cu3/4TiO3phase only starts after organics removal and full calcium carbonate elimination above 700 oC, which is followed by pore elimination and particle sintering. The chemical synthetic route used in this work shows the ability to prepare CCT powders sample with very structural homogeneity, which characteristics are required to manufacturing many electronic devices.
APA, Harvard, Vancouver, ISO, and other styles
33

Busuioc, Cristina, Andrada-Elena Alecu, Claudiu-Constantin Costea, Mihaela Beregoi, Mihaela Bacalum, Mina Raileanu, Sorin-Ion Jinga, and Iuliana-Mihaela Deleanu. "Composite Fibers Based on Polycaprolactone and Calcium Magnesium Silicate Powders for Tissue Engineering Applications." Polymers 14, no. 21 (October 30, 2022): 4611. http://dx.doi.org/10.3390/polym14214611.

Full text
Abstract:
The present work reports the synthesis and characterization of polycaprolactone fibers loaded with particulate calcium magnesium silicates, to form composite materials with bioresorbable and bioactive properties. The inorganic powders were achieved through a sol–gel method, starting from the compositions of diopside, akermanite, and merwinite, three mineral phases with suitable features for the field of hard tissue engineering. The fibrous composites were fabricated by electrospinning polymeric solutions with a content of 16% polycaprolactone and 5 or 10% inorganic powder. The physico-chemical evaluation from compositional and morphological points of view was followed by the biological assessment of powder bioactivity and scaffold biocompatibility. SEM investigation highlighted a significant reduction in fiber diameter, from around 3 μm to less than 100 nm after the loading stage, while EDX and FTIR spectra confirmed the existence of embedded mineral entities. The silicate phases were found be highly bioactive after 4 weeks of immersion in SBF, enriching the potential of the polymeric host that provides only biocompatibility and bioresorbability. Moreover, the cellular tests indicated a slight decrease in cell viability over the short-term, a compromise that can be accepted if the overall benefits of such multifunctional composites are considered.
APA, Harvard, Vancouver, ISO, and other styles
34

Chiririwa, H. "Characterization of Polymer Powders and Effects of Powder Reuse in Selective Laser Sintering." Asian Journal of Chemistry 33, no. 3 (2021): 658–64. http://dx.doi.org/10.14233/ajchem.2021.23065.

Full text
Abstract:
Selective laser sintering (SLS) had been recognized as production expertise (additive manufacturing). The complication restricting the use of SLS in additive manufacturing in an extensive range of industrial scope is the limited selection of usable polymers as it is only limited to polyamide 12. Other polymeric materials such as polypropylene and polyethylene are needed to establish pristine market avenues in industry. In selective laser sintering, the powder is reused in consecutive cycles of the route for the reason that it is sustainable and cost effective. Characterization procedures, including the many available techniques has been proposed to determine changes in chemical microstructures, morphology along with flowability. Subtle disimilarities linking virgin and used powder have been identified through characterization.
APA, Harvard, Vancouver, ISO, and other styles
35

Nguyen, My H., Sang-Jin Lee, and Waltraud M. Kriven. "Synthesis of oxide powders by way of a polymeric steric entrapment precursor route." Journal of Materials Research 14, no. 8 (August 1999): 3417–26. http://dx.doi.org/10.1557/jmr.1999.0462.

Full text
Abstract:
A polymerized organic–inorganic complexion route is introduced for the synthesis of yttrium aluminum garnet, YAG (Y3Al5O12) and cordierite (Mg2Al4Si5O18) powders. Long-chain polymers such as polyvinyl alcohol (–[CH2–CHOH]-n or PVA) or polyethylene glycol (H[O–CH2–CH2]nOH or PEG) were used as the organic carriers for a precursor ceramic gel. Calcined powders were very porous and homogeneous in distribution of components. Experimental studies by differential thermal analysis and thermogravimetric analysis, x-ray diffraction, solid-state nuclear magnetic resonance, and Fourier transform infrared spectrometry indicated that metal-ion chelation is not the primary mechanism for obtaining molecularly homogeneous precursor powders. Water-soluble cations of mixed oxides in the PVA or PEG process were sterically entrapped in the entangled network and resulted in fine and pure, mixed oxide powders.
APA, Harvard, Vancouver, ISO, and other styles
36

Gaki, Anna, C. Karavangelis, Glykeria Kakali, R. J. Wiglusz, and W. Strek. "Synthesis of La1-xSrxCoO3-δ by a Polymeric Precursor Route Using Microwave Heating." Materials Science Forum 636-637 (January 2010): 901–7. http://dx.doi.org/10.4028/www.scientific.net/msf.636-637.901.

Full text
Abstract:
La1-xSrxCoO3-δ (x=0, 0.2, 0.5) powders were prepared by a polymeric precursor route, with the application of microwave heating for the precursor preparation. Single-phase oxide powders are obtained after calcination at 700°C for x=0, 0.2 and 1300 °C for x=0.5. XRD, FTIR and TG-DTG measurements were used to examine the powder precursors as well as the intermediate and final products. SEM images indicated the small grain size of samples with x=0, 0.2. Conductivity and thermal expansion were measured by means of DC method and dilatometry respectively. The end member LaCoO3-δ showed a semiconducting behaviour, while doped samples showed a metallic behaviour at high temperatures. La0.8Sr0.2CoO3-δ showed the highest conductivity of all samples investigated, at temperatures higher than 300 °C.
APA, Harvard, Vancouver, ISO, and other styles
37

Scurati, Alberto, Ica Manas-Zloczower, and Donald L. Feke. "Influence of Powder Surface Treatment on the Dispersion Behavior of Silica into Polymeric Materials." Rubber Chemistry and Technology 75, no. 4 (September 1, 2002): 725–37. http://dx.doi.org/10.5254/1.3544998.

Full text
Abstract:
Abstract The effect of surface treatment on silica agglomerate dispersibility was investigated. Precipitated silica powders were treated with a commercially available coupling agent Bis-(triethoxysilylpropyl)-tetrasulphane (TESPT) in a blender. Spherical agglomerates of known density were prepared and dispersed in styrene butadiene rubber (SBR) under controlled flow conditions. The erosion kinetics was monitored by measuring the reduction in size of parent agglomerate with time. Silica dispersibility was greatly enhanced upon surface treatment. The coupling agent used in surface treatment is known to reduce filler—filler interactions and therefore affects the intrinsic cohesivity of the powder. However powder surface treatment can also induce changes in agglomerate morphology and filler-liquid interactions. The work presented in this paper evidences such changes.
APA, Harvard, Vancouver, ISO, and other styles
38

Zivkovic, Ljiljana, Biljana Stojanovic, C. R. Foschini, Vesna Paunovic, and Dragan Mancic. "Effects of powder preparation and sintering procedure on microstructure and dielectric properties of PLZT ceramics." Science of Sintering 35, no. 3 (2003): 133–40. http://dx.doi.org/10.2298/sos0303133z.

Full text
Abstract:
PLZT ceramics belong to one of the very important groups of functional materials that make a basis for the production of a large range of electronic devices. The microstructure and properties of ceramics depend on the powder preparation and thermal processing conditions. Various techniques have been used to obtain chemically homogeneous and fine starting powders PLZT powders have been prepared by two different production routes: by a modified Pechini method, using a polymeric precursor method (PMM) and by a partial oxalate method. A two-step sintering process, including a hot pressing, was carried out at 1100 and 1200?C. Distinct phases obtained during the sintering process have been investigated by SEM and EDS techniques and dielectric properties such as permittivity and dielectric loss were measured in a frequency range from 1 to 20 kHz. A significant difference in microstructure and dielectric properties, depending on powder origin and sintering procedure, has been noticed.
APA, Harvard, Vancouver, ISO, and other styles
39

Zhang, Jian Qiang, Hui Xia Feng, and Jian Hui Qiu. "Preparation and Properties Study on the Composites of Polypropylene and Polyphenylene Sulfide Filled by Modified Molybdenum Disulfide." Advanced Materials Research 87-88 (December 2009): 345–50. http://dx.doi.org/10.4028/www.scientific.net/amr.87-88.345.

Full text
Abstract:
The wet surface modification process were used in this work to get the well lipophilic molybdenum disulfide (MoS2) powders and the modified MoS2 were filled into the polyphenylene sulfide (PPS) and polypropylene (PP) powders with different proportions to make polymeric based composites through hot-press molding equipment. The Fourier transform infrared spectrometer (FT-IR) analysis showed that the modification agents of stearic acid (SA), orγ-Methacryloxypropyl trimethoxy silane(KH570 or A-174), could react with the adsorption hydroxyl(−OH) of the MoS2 powders and finally form chemical coatings, the SA could form a layer of physics wrap too. The powder X-ray diffraction (XRD) analysis reveled that the SA or KH570 could not change the laminated structure of MoS2. The wearability testing showed that the composites filled by modified MoS2 owned the better wearable performances than the filled not one. From minimum to maximum, the wear mass rates of SA/MoS2/PP/PPS, KH570/MoS2/PP/PPS, PP/PPS were 0.7216, 5.4187 and 7.3198 percent in turns. Scanning electronic microscope (SEM) analysis showed the surface modification could uniformize the modified MoS2 to disperse in the polymeric based composites, and also reflect the abrasion mechanism which the particles and the adhering wear modes could all make the mass loss of the testing samples and they coexisted and could transform each other, the former would produce higher loss rates than the later and their leader status would gradually change from the particles wear to the adhering wear during the course of wearing-resisting tests.
APA, Harvard, Vancouver, ISO, and other styles
40

da Silva, Margarete Soares, Lucas L. da Silva, Eliane F. de Souza, Talita Cuenca Pina Moreira Ramos, Igor Silva de Sá, Graciele Vieira Barbosa, Elson Longo, and Alberto Adriano Cavalheiro. "Structural Effects on Perovskite Phase Formation for PZT Powders Obtained by Polymeric Precursor Method." Materials Science Forum 930 (September 2018): 101–6. http://dx.doi.org/10.4028/www.scientific.net/msf.930.101.

Full text
Abstract:
Many synthesis methods are available to obtain a set of specific characteristics for lead zirconate titanate (PZT) piezoelectric ceramic powders. In this work, we have successfully prepared PZT powder samples through the Polymeric Precursor Method with x = 0.6, according the general formula Pb (ZrxTi1-x)O3. The powders were thermally treated from 380 to 550 oC and characterized by Raman spectroscopy and X-ray diffraction (DRX) in order to evaluate the effects of thermal treatment on the phase formation and the crystallization processes. The results obtained by Raman spectroscopy were compared to refined crystal data obtained by Rietveld method, leading to coherent conclusions about the structural effects occurring along the temperature of calcination. It was possible to characterize the tetragonal perovskite phase as predominant phase occurs only after 500 oC, but its crystallinity is already determined by synthesis method. Thus, no ordering process is verified for perovskite as a function of the temperature increasing during thermal treatment, in spite of the continuous pyrochlore-to-perovskite phase transition. The pyrochlore secondary phase starts to vanish before its proper crystallization process, changing the tetragonality of previously formed perovskite phase.
APA, Harvard, Vancouver, ISO, and other styles
41

Miranda, Margarida S., Márcia T. Rodrigues, Rui M. A. Domingues, Egídio Torrado, Rui L. Reis, Jorge Pedrosa, and Manuela E. Gomes. "Exploring inhalable polymeric dry powders for anti-tuberculosis drug delivery." Materials Science and Engineering: C 93 (December 2018): 1090–103. http://dx.doi.org/10.1016/j.msec.2018.09.004.

Full text
APA, Harvard, Vancouver, ISO, and other styles
42

Tavora Weber, Ingrid, Nathalie Audebrand, Valérie Bouquet, Maryline Guilloux-Viry, and André Perrin. "KTaO3 powders and thin films prepared by polymeric precursor method." Solid State Sciences 8, no. 6 (June 2006): 606–12. http://dx.doi.org/10.1016/j.solidstatesciences.2006.01.011.

Full text
APA, Harvard, Vancouver, ISO, and other styles
43

Lopes, K. P., L. S. Cavalcante, A. Z. Simões, J. A. Varela, E. Longo, and E. R. Leite. "NiTiO3 powders obtained by polymeric precursor method: Synthesis and characterization." Journal of Alloys and Compounds 468, no. 1-2 (January 2009): 327–32. http://dx.doi.org/10.1016/j.jallcom.2007.12.085.

Full text
APA, Harvard, Vancouver, ISO, and other styles
44

De Girolamo Del Mauro, Anna, Giuseppe Nenna, Riccardo Miscioscia, Cesare Freda, Sabrina Portofino, Sergio Galvagno, and Carla Minarini. "Nonvolatile RRAM Cells from Polymeric Composites Embedding Recycled SiC Powders." Langmuir 30, no. 41 (October 7, 2014): 12421–28. http://dx.doi.org/10.1021/la503060v.

Full text
APA, Harvard, Vancouver, ISO, and other styles
45

Martínez, Jesús Mauricio González, Rodrigo Arabey Muñoz Meneses, and Cosme Roberto Moreira da Silva. "Synthesis of Gadolinium Doped Ceria Ceramic Powder by Polymeric Precursor Method (Pechini)." Materials Science Forum 798-799 (June 2014): 182–88. http://dx.doi.org/10.4028/www.scientific.net/msf.798-799.182.

Full text
Abstract:
The synthesis by polymeric precursors method (Pechini) was used to acquire gadolinium doped ceria forming Ce0,8Gd0,2O1,9 system, reaching high stoichiometric control features and nanosized particles to form dense solid electrolyte of high ionic conductivity. The synthesis was performed with cerium and gadolinium nitrates hexahydrates, citric acid and ethylene glycol. After the pre-calcination at 250°C/18h a resin was obtained like an expanded foam (puff). According to the iterature, this fact indicates that there is a reduction of agglomerates amount in a ceramic powder. A thermogravimetry-differential thermal analysis evaluated the thermal behavior of the resin. Infrared spectroscopy determined the organic matter and nitrates presence, before and after the calcination process. The X-ray diffraction identified the fluorite-type structure and was determined the crystallite size by the Scherrer equation in 22 and 46 nm for the powder calcined respectively at 600 and 800°C. The scanning electron microscopy evaluated the agglomeration degree and the morphology of the powders.
APA, Harvard, Vancouver, ISO, and other styles
46

Abbinante, Vincenzo Mirco, Gonzalo García-Espejo, Gabriele Calabrese, Silvia Milita, Luisa Barba, Diego Marini, Candida Pipitone, Francesco Giannici, Antonietta Guagliardi, and Norberto Masciocchi. "Conformationally rigid molecular and polymeric naphthalene-diimides containing C6H6N2 constitutional isomers." Journal of Materials Chemistry C 9, no. 33 (2021): 10875–88. http://dx.doi.org/10.1039/d1tc00564b.

Full text
Abstract:
New molecular and polymeric NDI-based materials, containing constitutional isomers of aromatic amines, have been prepared as powders and thin films, studied by XRD and grazing-incidence diffraction methods, and compared to n-alkyl aliphatic congeners.
APA, Harvard, Vancouver, ISO, and other styles
47

Gaspar, J., P. J. Bártolo, and Fernando M. Duarte. "Cure and Rheological Analysis of Reinforced Resins for Stereolithography." Materials Science Forum 587-588 (June 2008): 563–67. http://dx.doi.org/10.4028/www.scientific.net/msf.587-588.563.

Full text
Abstract:
The rising of consumers’ demands and an ever increasing pressure of international markets imposed a deep change in the product development process to respond to an increasing product complexity and higher quality, as well to the need to promptly introduce products into the market. Stereolithography plays an important role on this new product development context. This technology produces models for thermosetting resins through a polymerisation process that transforms liquid resins into solid materials. In this work, a new route to produce metallic parts through stereolithography is explored. The curing analysis of hybrid reinforced polymeric systems, polymerised through radicalar or/and cationic mechanisms, is investigated. The rheological behaviour of these polymeric systems is also evaluated due to its importance for recoating. The influence of other processing and material characteristics like light intensity, initiator concentration, low powder size of metallic powders, degree of dilution, etc. is also investigated.
APA, Harvard, Vancouver, ISO, and other styles
48

Bobbala, Sharan, Michael P. Vincent, and Evan A. Scott. "Just add water: hydratable, morphologically diverse nanocarrier powders for targeted delivery." Nanoscale 13, no. 26 (2021): 11349–59. http://dx.doi.org/10.1039/d1nr02188e.

Full text
Abstract:
We present a storage-stable carbohydrate-based powder technology that forms monodisperse polymeric nanocarriers of diverse morphology upon simple hydration. This platform loads a wide range of cargoes and is capable of targeted delivery.
APA, Harvard, Vancouver, ISO, and other styles
49

Gorbunov, A. V., O. G. Devoino, V. A. Gorbunova, O. K. Yatskevitch, and V. A. Koval. "Thermodynamic Estimation of the Parameters for the C–H–O–N–Me-Systems as Operating Fluid Simulants for New Processes of Powder Thermal Spraying and Spheroidizing." Science & Technique 20, no. 5 (October 7, 2021): 390–98. http://dx.doi.org/10.21122/2227-1031-2021-20-5-390-398.

Full text
Abstract:
Over the past few years, a group of new processes was developed for high-temperature, including plasma electric arc spraying (at ambient pressure) and spheroidizing of some ceramic and metal powder materials with the use of gaseous hydrocarbons in the heat carriers as well as with feeding of organic additions into a high-temperature jet, in particular, polymeric ones, to control porosity of sprayed metallic functional coatings. The paper considers the possibility to modify such technological processes by introducing solid fuel additions of a polymer type into the operating fluid of an apparatus for gasthermal (plasma or other) treatment, which provides melting of metal or oxide powders. For this, with the help of thermodynamic analysis, the processes have been evaluated at temperatures (300–3000) K for the set of such reacting five component systems as C–H–O–N–Me (at ambient pressure 0.101 MPa) with five variants of Ме – aluminum, titanium, chrome, copper, nickel. This makes it possible to consider these systems as simulants for potential technologies for the treatment of oxide powders (Al2O3, TiO2, Cr2O3) as well as metallic ones (Cu, Ni and their alloys). In order to obtain high exothermic contribution to the heating of powders, the combination “air + polymeric addition (polyethylene) of LDPE grade” was chosen as mixed heat carrier (operating fluid) for the basic version of simulated process. During the analysis of equilibria for the considered multicomponent systems (17 variants), a set of following parameters has been used to characterize the energy intensity of the target powder heating process: the equivalence ratio for reacting mixture and its adiabatic temperature; the energy efficiency of material heating with and without taking into account the effect of fuel addition; specific energy consumption for the powder melting; autothermicity degree of the process during the combined heating (electrothermal heating by the arc of plasma torch and heat flux from the “air + solid fuel additions” mixture) of refractory powders. As a result of the assessment, the preferred (from thermodynamic standpoint) regimes of the considered processes have been found and the possibility to realize an energy-efficient heating of these oxide and metal materials (without oxidation of the latter to CuOx, NiO) with a reduced part of the electric channel of energy transfer, resulted from the carrying out of appreciable effect of the fuel-initiated mechanism of heating in the analyzed C–H–O–N–Mesystems, has been shown in the paper.
APA, Harvard, Vancouver, ISO, and other styles
50

Firmino, H. C. T., A. J. M. Araújo, R. P. S. Dutra, R. M. Nascimento, S. Rajesh, and D. A. Macedo. "One-step synthesis and microstructure of CuO-SDC composites." Cerâmica 63, no. 365 (March 2017): 52–57. http://dx.doi.org/10.1590/0366-69132017633652088.

Full text
Abstract:
Abstract An in situ one step synthesis route based on the polymeric precursor method was used to produce dual phase CuO-samaria doped ceria (SDC) nanocomposite powders. This chemical route allowed to obtain composite powders with reduced particle size and uniform distribution of Cu, Ce and Sm elements. The particulate material was characterized by powder X-ray diffraction (XRD) combined with Rietveld refinement. CuO-SDC sintered in air between 950 to 1050 °C and subsequently reduced to Cu-SDC cermets were further characterized by XRD and scanning electron microscopy. The open porosity was measured using the Archimedes’ principle. Suitable microstructures for both charge transfer and mass transport processes (30 to 45% porosity) were attained in Cu-SDC cermets previously fired at 1000 to 1050 °C. Overall results indicated that CuO-SDC composites and Cu-SDC cermets with potential application as anodes for solid oxide fuel cells (SOFCs) can be obtained by microstructural design. An anode supported half-cell was prepared by co-pressing and co-firing gadolinia doped ceria (CGO) and the herein synthesized CuO-SDC nanocomposite powder.
APA, Harvard, Vancouver, ISO, and other styles
You might also be interested in the bibliographies on the topic 'Polymeric Powders' for other source types:
Dissertations / Theses Books
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography