Microcrystal Particles Behaviour in Inkjet Printing of Reactive Nylon Materials

2013 ◽  
Vol 135 (1) ◽  
Author(s):  
Saeed Fathi ◽  
Phill Dickens ◽  
Khosrow Khodabakhshi ◽  
Marianne Gilbert
Keyword(s):  
Inkjet Printing ◽  
Polarized Light ◽  
Magnesium Bromide ◽  
Catalyst Complex ◽  
Layer Manufacturing ◽  
Quantitative Image ◽  
Molten Materials ◽  
Manufacturing Applications ◽  
Individual Droplet ◽  
Kinetics Of

A novel process using inkjet printing of molten materials to produce nylon 6 for additive layer manufacturing applications was investigated. Different reactive mixtures of molten caprolactam with activator and catalyst were characterized for physical properties to understand their jettability in an inkjet system. Although it was found that the surface tension and viscosity of all materials were within the range suitable for inkjet technology according to the literature, microcrystals of undissolved salt of the catalyst complex (caprolactam magnesium bromide) were found to influence melt supply behavior. The influence of the process on the catalyst microcrystal consistency and agglomeration beyond the jetting system was investigated for purged, deposited multiple droplets and also individual droplet samples using hot-stage polarized light microscopy. Quantitative image analysis showed that although microcrystal agglomeration occurred within the accumulated droplets due to kinetics of droplet impact, this however was much less than with the purged samples. A generally consistent content and dispersion of the microcrystals existed within the consecutively deposited droplets.

Engineering the microstructure of milk fat by blending binary and ternary mixtures of its fractions

RSC Advances ◽  
2016 ◽  
Vol 6 (47) ◽  
pp. 41189-41194 ◽  
Author(s):  
Pere R. Ramel ◽  
Alejandro G. Marangoni
Keyword(s):  
Light Microscopy ◽  
Crystallization Kinetics ◽  
Isothermal Crystallization ◽  
Milk Fat ◽  
Polarized Light ◽  
Ternary Mixtures ◽  
Avrami Model ◽  
Binary And Ternary Mixtures ◽  
Milk Fat Fractions ◽  
Kinetics Of

The microstructure and crystallization kinetics of binary and ternary mixtures of milk fat fractions during isothermal crystallization at 5, 15, and 20 °C were characterized using polarized light microscopy and the Avrami model.

scholarly journals Non-Isothermal Crystallization Kinetics of Injection Grade PHBV and PHBV/Carbon Nanotubes Nanocomposites Using Isoconversional Method

2020 ◽  
Vol 4 (2) ◽  
pp. 52
Author(s):  
Thaís Larissa do Amaral Montanheiro ◽  
Beatriz Rossi Canuto de Menezes ◽  
Larissa Stieven Montagna ◽  
Cesar Augusto Gonçalves Beatrice ◽  
Juliano Marini ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Crystallization Kinetics ◽  
Isothermal Crystallization ◽  
Model Fitting ◽  
Polarized Light ◽  
Isoconversional Method ◽  
Degree Of Crystallinity ◽  
Gamma Aminobutyric Acid ◽  
Scanning Calorimetry ◽  
Kinetics Of

Carbon nanotubes (CNT)-reinforced polymeric composites are being studied as promising materials due to their enhanced properties. However, understanding the behavior of polymers during non-isothermal crystallization is important once the degree of crystallinity and crystallization processes are affected when nanoparticles are added to matrices. Usually, crystallization kinetics studies are performed using a model-fitting method, though the isoconversional method allows to obtain the kinetics parameter without assuming a crystallization model. Therefore, in this work, CNTs were oxidized (CNT-Ox) and functionalized with gamma-aminobutyric acid (GABA) (CNT-GB) and incorporated into a poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) matrix. The influence of the addition and functionalization of CNT in the crystallization kinetics of PHBV was evaluated using the isoconversional method with differential scanning calorimetry (DSC), and by polarized light optical microscopy (PLOM) and Shore D hardness. The incorporation and functionalization of CNT into PHBV matrix did not change the Šesták and Berggren crystallization model; however, the lowest activation energy was obtained for the composite produced with CNT-GB, suggesting a better dispersion into the PHBV matrix. PLOM and Shore D hardness confirmed the results obtained in the kinetics study, showing the smallest crystallite size for CNT-containing nanocomposites and the highest hardness value for the composite produced with CNT-GB.

Microstuctural Evolution and Substrate Selectivity in Pecvd μc-Si

1992 ◽  
Vol 283 ◽  
Author(s):  
Gregory N. Parsons ◽  
John J. Boland ◽  
James C. Tsang
Keyword(s):  
Hydrogen Plasma ◽  
Chemical Vapor ◽  
Process Conditions ◽  
Microcrystalline Silicon ◽  
Selective Area ◽  
Initial Nucleation ◽  
Bond Strain ◽  
Manufacturing Applications ◽  
Kinetics Of ◽  
Area Deposition

ABSTRACTWe discuss a process for selective area deposition of microcrystalline silicon (μc-Si) using plasma enhanced chemical vapor deposition at low substrate temperature (<300°C) using time modulated silane flow in a hydrogen plasma. We discuss selectivity and deposition rate on a variety of substrates with process conditions important for manufacturing applications, and show a distinct microstructural evolution in the initial nucleation layers using Raman spectroscopy that correlates with the transition from selective to non-selective growth. Atomic hydrogen discriminates between different degrees of bond strain in the nucleii formed on different substrates, and can increase the crystallinity fraction in films deposited at low temperatures by modifying the kinetics of bulk-like bond formation.

scholarly journals Kinetics of Sucrose Inversion in Mixed Solvents

2017 ◽  
Vol 15 (1-2) ◽  
Author(s):  
Branko Škundrić ◽  
Bogoljub Antonić ◽  
Jelena Penavin-Škundrić ◽  
Rada Petrović ◽  
Ljubica Vasiljević
Keyword(s):  
Reaction Rate ◽  
Aqueous Ethanol ◽  
Mixed Solvents ◽  
Polarized Light ◽  
Sulfuric Acid Concentration ◽  
Pseudo First Order Reaction ◽  
First Order ◽  
Acid Environment ◽  
Acid Catalyzed ◽  
Kinetics Of

Sucrose solvolysis was observed under the same conditions in water and in mixed solvents of aqueous ethanol and aqueous dimethyl sulfoxide. The reaction is a specifically acid catalyzed one and occurs as a pseudo first order reaction. Influence of the catalyst (sulfuric acid) concentration was observed and spontaneous and catalytic constants of reaction rate were calculated. The reaction was observed by a polarimetric method of examining the angle of polarized light plane rotation in the course of the reaction in an acid environment at 298K. The obtained experimental results were interpreted based on the Hughes-Ingold theory of the effect of ionizing power of a solvent onto the reaction in the solvent.

Characterization and photoinduced properties of photo chromic polymers. 1. Polyesterimides with 4-amino 4´-nitro azobenzene moieties

e-Polymers ◽  
2006 ◽  
Vol 6 (1) ◽  
Author(s):  
Ewa Schab-Balcerzak ◽  
Beate Sapich ◽  
Joachim Stumpe ◽  
Anna Sobolewska ◽  
Andrzej Miniewicz
Keyword(s):  
Optical Anisotropy ◽  
Polarized Light ◽  
Ethyl Benzene ◽  
H Nmr ◽  
Azobenzene Group ◽  
Vis Spectroscopy ◽  
Different Types ◽  
Linearly Polarized ◽  
Kinetics Of ◽  
Dsc Thermograms

AbstractNovel photochromic polyesterimides (PEIs) with two different types of azobenzene units as side groups have been synthesized from 2,2’-{4-[(4- nitrophenyl)-azo} phenyl]iminobis(ethyl benzene-1,2-dicarboxylic acid anhydride-4- carboxylate) and diamines: 2,4-diamino-4’-methylazobenzene and 2,4-diamino-4’- (trifluoromethoxy)azobenzene. An analogous polyesterimide with one azobenzene group based on 1,3-phenylendiamine has been prepared to compare with these PEIs. Molecular structural characterization for these polymers has been achieved by FTIR, 1H NMR and UV-Vis spectroscopy. These amorphous polyesterimides are thermally stable up to 260°C as follows from the thermogravimetric analysis (TGA). The glass transition temperatures (Tg) for the resulting polyimides have been determined from DSC thermograms and are in the range of 141-210°C. The irradiation with linearly polarized light of an Ar+ laser results in the induction of optical anisotropy within the initially isotropic films. Light induced optical anisotropy in polymer films has been studied by examining the value of generated dichroism using Ar+ laser (λ = 488 nm) and by holographic polarization grating recording performed at λ = 514.5 nm. The value of photoinduced dichroism is in the range of 0.15-0.26. The induction of dichroism and kinetics of grating inscription have been investigated in relation to the presence of the second type of azobenzene group in the polymer and its substitution.

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