Spherulitic crystallization

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WebMar 23, 2014 · The crystal growth proceeds as the stacks of lamellar crystals and amorphous layers in between. (c, e, f) When polymers are crystallized from the melt, … WebIt is established that phase field methods naturally account for diffusional instabilities that are responsible for dendritic single-crystal growth. However, a generalization of this …

Spherulitic Crystallization in Polypropylene: Journal of Applied ...

WebJul 20, 2004 · (III) A discussion is given concerning the shape of the bulk‐crystallization isotherms associated with spherulitic growth, including stage‐1 and stage‐2 crystallization, and the presence of amorphous material in the spherulites. REFERENCES 1. P. H. Geil, J. Appl. Phys. 33, 642 (1962). Google Scholar Scitation 2. J. D. WebSpherulite is a spheriform aggregate of chain-folded fibrillar or lamellar primary crystallites. According to a simplified model, crystallites start from a central, pin-point type nucleus … symbool athena

Spherulitic crystallization and structure SpringerLink

WebPP developed spherulites, whose growth was unaffected by blending, while its overall isothermal crystallization kinetics was strongly influenced by nucleation effects caused by blending. Addition of nanosilica resulted in an enhancement of the strain at break of PP-PC blends whereas it was observed to weaken PP-PA blends. WebJun 16, 2004 · ABSTRACT. A survey has been made of spherulites formed by the isothermal crystallization of polypropylene from the melt in the temperature range 110°–148°C. Four types of spherulite have been distinguished and their structural morphology, optical properties, melting behavior, and growth rates have been examined. WebNov 4, 2024 · Spherulites are the most common crystalline morphology and thus the visual expression of crystal structures for polymers. The diversified patterns have provided intuitive morphology probes for various crystallization behaviors, while the correlations between them are still needed to be enriched. th4110d1007 honeywell

A Phenomenological Theory of Spherulitic Crystallization

Theory of spherulitic crystallization — University of Illinois …

WebWe have proposed that spherulitic crystallization, if not the actual mechanism, serves as a viable model for granule initiation in vivo and that the results of this research will further the understanding of this still mysterious but highly significant biological phenomenon. symbool audiWebNone of the bundlelike models will lead to a typical lamellar spherulite, though a spherical microcrystalline object might be formed. It is concluded that lamellar spherulites consist largely of chain folded structures. The factors that could cause chain folded crystals to appear in profusion in bulk polymers are discussed. symbool bancontact

"WebFeb 1, 2011 · Spherulitic crystallization of β‐In2Te3 by physical vapour deposition. Different morphologies of indium telluride (In2Te3) including novel spherulites were crystallized … " - Spherulitic crystallization

Spherulitic crystallization

WebThe growth of spherulitic crystal patterns in a Belousov–Zhabotinski (BZ) type reaction system by using acetyl acetone (AA)– succinic acid (SA) as dual organic substrates has … WebMar 18, 2016 · A method of gradient cooling-down isothermal crystallization was used to prepare layered spherulites. The polyester was dissolved in chloroform to obtain a uniform solution (3 wt% for PLLA and 2 wt% for PHB). A drop of the solution was cast and uniformly spread on a clean glass slide.

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WebJan 28, 1999 · Chitosan crystallization, performed by simple drying of an oligomer or polymer solution on a glass or mica surface, was studied at room temperature. Polarizing … WebThe proto-dolomite crystallization proceeds via spherulitic growth that follows a growth front nucleation mechanism with a de-nuovo and continuous formation of nanocrystalline proto-dolomite subunits that form spherical aggregates. In stage three of the reaction, the proto-dolomite transforms to highly crystalline and stoichiometric dolomite on ...

WebJan 1, 2001 · Spherical crystal can be formed as types of agglomerates and spherulites. Agglomerated crystals are the unification of small primary particles after primary nucleation. Agglomeration technique is to transform fine crystals directly into compacted crystals during crystallization. WebJun 25, 2024 · Propylene-based random copolymers with either ethylene or 1-hexene as comonomer, produced using a metallocene catalyst, were studied regarding their crystallization behaviors, with a focus on rapid cooling. To get an impression of processing effects, fast scanning chip calorimetry (FSC) was used in addition to the characterization …

WebSep 24, 2001 · Spherical crystals of explosives can improve insensitivity toward a sudden shock, its performance, processablity and packing density. As a result, desirable shape of … WebSubsequent DSC scans of isothermally crystallized PBS and PBSR exhibited two melting endotherms, respectively, which was due to the melt-recrystallization process occurring …

WebOct 25, 2024 · A homogenous spherulitic crystallization results in pinhole-free films with similar microstructure irrespective of processing environment. This study further …

WebJun 4, 2024 · The theory of spherulitic crystallization is here applied to sedimentary deposits for the first time. The intimate association of calcite and quartzine in the concretions requires a chemical change from alkaline to acidic conditions, which occurs below the carbonate-reduction zone owing to the dissolution of sponge spicules or … th4110d1007 recoveryWebSep 24, 2001 · Spherical crystals of explosives can improve insensitivity toward a sudden shock, its performance, processablity and packing density. As a result, desirable shape of explosives is a spherical spherulite. In our previous works [2], [3], spherically spherulitic crystallization of 3-nitro-1,2,4-triazol-5-one (NTO) has been described. th4110d1007 honeywell thermostatWebOct 11, 2024 · Spherulitic growth rate is related to the crystallization temperature and is nonlinear in non-isothermal conditions of the polymeric blends. The POM shown in Figure 1 , the spherulitic growth rate of the blends presents regular growth with the addition of LMPP contents, affecting the size and shape of the spherulites. symbool autotransformatorWebThese results provide quantitative support for the mechanism of spherulitic growth proposed by Keith and Padden. AB - I show that diffusion-controlled growth can account … symbool bosWebNov 4, 2010 · Spherulitic crystals are found in association with many materials and diseases, but the fundamental formation mechanism is not well understood. Using maleic chitosan to control CaCO 3 crystallization, we have discovered a two-stage process that produces biomimetic CaCO 3 spherulites. symbool balpenWebJan 1, 2004 · The spherulitic aggregate is too fine grained to be determined directly of what minerals it is composed. Bigger spherulites have a much more complicated inner structure. The alkali feldspar is... th4110d1007 manual pdfWebkeith, h.d., spherulitic crystallization from melt .i. fractionation + impurity segregation + their influence on crystalline morphology, journal of applied physics 35: 1270 (1964). Google Scholar KELLER, A, THE SPHERULITIC STRUCTURE OF CRYSTALLINE POLYMERS .2. symbool australie