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Poly(p-dioxanone) (PPDO) is crystallized with amorphous poly(p-vinyl phenol) (PVPh) and tannic acid (TA) as co-diluents to regulate and induce dendritic-ringed PPDO spherulites, with spoke- or sector-bands, aiming for convenience of analyses on interior lamellar assembly. Morphologies and interior lamellar arrangement leading to the peculiar rings on individual dendrites are evaluated by using polarized-light microscopy (PLM) and scanning electron microscope (SEM). Combinatory microbeam small-/wide-angle X-ray scattering (SAXS/WAXS) analyses further confirm the unique assembly patterns in periodic cycles. Alternate gratings are packed with periodic ridges composed of feather-like branches and the valley is featured with some embossed textures. The periodic gratings in the ringed spokes resemble those in nature's structured coloration and are proven to display light-interference iridescence. [ABSTRACT FROM AUTHOR]

The grating structure and periodic assembly in D -(−)-poly(3-hydroxybutyrate) (PHB), or simply poly(3-hydroxybutyrate), with diluent-modulated optical regularity are analyzed using microscopy techniques coupled with a unique 3D interior dissection technique. The top-surface valley band is a result of impingement of branching crystals evolving from normal-oriented main lamellar stalks, and the top-surface band is a result of the protruding lamellar stalks. The 3D dissection shows direct experimental proof of discontinuous interfaces between the successive bands, which are created by periodic impingement of neighboring lamellar bundles growing in the normal direction from the substrate. The iridescence phenomenon from the PHB periodic bands can be attributed to the grating-assembly structures with cross-bar pitches tuned to a suitable range by combination of diluents and temperature of growth, whose function resembles those seen in nature's iridescent crystals. [ABSTRACT FROM AUTHOR]

In this study, five different aryl polyesters, i.e., poly(ethylene terephthalate) (PET), poly(trimethylene terephthalate) (PTT), poly(octamethylene terephthalate) (POT), poly(nonamethylene terephthalate) (PNT), and poly(decamethylene terephthalate) (PDT), upon crystallization at a suitable temperature range, all exhibit ring-banded spherulites with universal characteristics. Previous research has revealed some fundamental mechanisms underlying the formation of periodic hierarchical structures. Additionally, this study further explored correlations among micro/nanocrystal assemblies in the top surface and internal grating architectures and the structural iridescent properties. The interior lamellar assembly of arylate polyesters' banded spherulites is shown to exhibit periodic birefringence patterns that are highly reminiscent of those found in a variety of biological structures, with the capacity for iridescence from light interference. A laser diffraction analysis was also used to support confirmation of this condition, which could result in an arc diffraction pattern indicative of the presence of ringed spherulites. Among the five arylate polyesters, only PET is incapable of regularly producing ring-banded morphology, and thus cannot produce any iridescent color. [ABSTRACT FROM AUTHOR]

This study used scanning electron microscopy via 3D dissection coupled with synchrotron radiation with microfocal beams of both small-angle X-ray scattering and wide-angle X-ray diffraction to analyze the periodic crystal aggregates of unusual poly(p-dioxanone) (PPDO) dendritic cactus-arm-like ring bands upon crystallization with a diluent poly(vinyl alcohol) (PVA) that is capable of hydrogen bonding interactions with PPDO. Three-dimensional microscopy interior dissection clearly expounds that the banded periodic architectures are packed by alternately normal-oriented flat-on crystals underneath the valley, periodically interfaced/branched with horizontal-oriented edge-on fibrils underneath the ridge. The oblique angles between the valley's flat-on crystals with the branches are ca. 25–45° (depending on gradient inclines and bending), which is also proved by the azimuthal angle in microbeam X-ray diffraction. The grating-like strut-rib assembly in the PPDO cactus-arm-like ring bands is further proved by novel iridescence tests. [ABSTRACT FROM AUTHOR]

Self-assembly of 3D interiors and iridescence properties of poly(β-hydroxybutyric acid-co-β-hydroxyvaleric acid) (PHBV) periodic crystals are examined using microcopy techniques and microbeam X-ray diffraction. Morphology of PHBV can be tailored by crystallizing in presence of poly(vinyl acetate) (PVAc) or poly(trimethylene adipate) (PTA) for displaying desired periodicity patterns. The regular alternate-layered lamellae of banded PHBV crystal aggregates, resembling the structures the natural mineral moonstone or nacre, are examined to elaborate the origin of light interference and formation mechanisms of periodic lamellar aggregation of PHBV spherulites. By using PHBV as a convenient model and the crystal diffraction data, this continuing work demonstrates unique methodology for effectively studying the periodic assembly in widely varying polymers with similar aggregates. Grating structures in periodically assembled polymer crystals can be tailored for microstructure with orderly periodicity. [ABSTRACT FROM AUTHOR]

Poly(octamethylene terephthalate) (POT), self-assembled with periodically banded aggregates, are analyzed using polarized-light optical microscopy and scanning electron microscopy. POT can display banded spherulites (with blue/orange tint colors), depending on crystallization temperature. 3D interior morphology dissection is conducted to reveal the gratinglike architecture of POT periodically banded crystal aggregates. The grating assembly is composed of onion-like layers (i.e., corrugate-board cross-hatches), with distinctly discontinuous interfaces existing between the successive layers, and each layer is composed of tangential-oriented fibrous lamellae and plate-like radial-oriented ones. Novel findings confirm that the interior gratings of ring-banded POT are comparable to the grating micro-structures commonly seen in nature's biospecies such as butterfly's wings. The POT microstructures could be finely modulated and tailored-made to functional applications as interfacial coating materials for performing photonics iridescence. [ABSTRACT FROM AUTHOR]

This work used several model arylate polymers with the number of methylene segment n = 3, 9, 10, and 12, which all crystallized to display similar types of periodically banded spherulites at various Tc and kinetic factors. Universal mechanisms of nano- to microscale crystal-by-crystal self-assembly to final periodic aggregates showing alternate birefringence rings were probed via 3D dissection. The fractured interiors of the birefringent-banded poly(decamethylene terephthalate) (PDT) spherulites at Tc = 90 °C revealed multi-shell spheroid bands composed of perpendicularly intersecting lamellae bundles, where each shell (measuring 4 μm) was composed of the interior tangential and radial lamellae, as revealed in the SEM results, and its shell thickness was equal to the optical inter-band spacing (4 μm). The radial-oriented lamellae were at a roughly 90° angle perpendicularly intersecting with the tangential ones; therefore, the top-surface valley band region appeared to be a submerged "U-shape", where the interior radial lamellae were located directly underneath. Furthermore, the universal self-assembly was proved by collective analyses on the three arylate polymers. [ABSTRACT FROM AUTHOR]

Polarized optical microscopy (POM), scanning electron microscopy (SEM), and synchrotron microbeam wide-angle X-ray diffraction (WAXD) were used to investigate the mechanisms of periodic assemblies leading to ring-banded crystal aggregates with light-grating capacity for iridescence in poly (1,4-butylene adipate) (PBA) modulated with poly (ethylene oxide) (PEO). A critical finding is that the PBA crystal assembly on the top surface and in the interior constitutes a grating architecture, with a cross-bar pitch equaling the inter-band spacing. The inner lamellae are arranged perpendicularly to the substrate under the ridge region, where they scroll, bend, and twist 90° to branch out newly spawned lamellae to form the parallel lamellae under the valley region. The cross-hatch grating with a fixed inter-spacing in the PBA aggregated crystals is proved in this work to perfectly act as light-interference entities capable of performing iridescence functions, which can be compared to those widely seen in many of nature's organic bio-species or inorganic minerals such as opals. This is a novel breakthrough finding for PBA or similar polymers, such as photonic crystals, especially when the crystalline morphology could be custom-made and modulated with a second constituent. [ABSTRACT FROM AUTHOR]

Poly(ethylene succinate) (PESu), upon crystallization with a morphology‐modulating diluent and at low degree of supercooling, forms peculiarly novel sector‐face dendritic aggregates. Delicate dissection by various microscopic techniques is used to confirm the unique differences of these two faces in the PESu dendrites. Powerful synchrotron‐source generated X‐ray microbeam analysis is performed to prove without doubt the nature of the single crystals that self‐assemble into these two sectors, respectively. Both microscopy results and 1D/2D wide‐angle X‐ray patterns collectively confirm that one sector‐face of the PESu dendrites is composed all fully flat‐on with the single‐crystal's basal face contacting the substrate and branching growth with mutual perpendicular ≈90° angle intersections; the second face is composed fully edge‐on with the prism face contacting the substrate and growth with mutual oblique 5–30° angle intersections. The growth intersection angles are also proved by the azimuthal angles in 1D and 2D X‐ray patterns. [ABSTRACT FROM AUTHOR]

Crystal assembly by crystallization and self-aggregation into periodicity, viewed as circular ring bands in optical birefringence patterns, in the family of aliphatic polyesters is surveyed. The periodic packing in all polyesters shares similarity of grating architectures in interiors and banding on top surfaces. More intereistingly, such grating structures in ring-banded polyesters can display interfacial photonics to cause optical light interference into colors. The unique periodic morphology and top-surface and interior architectures are explored in greater details using two polyesters in homologous series: poly(ethylene adipate) (PEA), poly(1,4-butylene adipate) (PBA), biodegrable poly(ε-caprolactone) (PCL), and poly(β-hydroxy butyrate) (PHB), which serve as ideal models for focused discussions on their photonics with periodic gratings. Analysis of the interior lamellae from ringless to periodically ordered aggregates is conducted for comparisons. Universally, the grating structure is composed of interior tangential lamellae intersecting with radial lamellae mutually at 60–90° angle, resembling shish-kebab or cross-hatch assembly. The cross-bar pitch of the interior gratings in all periodically banded polymer aggregates is invariably equal to the optical inter-band spacing as viewed in their optical birefringence patterns. 3D assembly mechanisms of periodically banded crystals are also responsible for the orderly ring arrays on top surfaces. The interior microstructures of alternate-layered assembly resemble the nature's photonic crystals. [ABSTRACT FROM AUTHOR]

Kinetically sluggish growth of poly(ε-caprolactone) at high Tc = 50 °C leads to a peculiar banding morphology, where thick-stacked lamellae self-assemble into camellia-petal-like bands with their outer rims divided into a ca. 10 lobs of round-shaped petals. The sluggish growth at Tc = 50 °C thick films is inductive and the thickened lamellae self-assemble into aggregates of peculiar and novel camellia-petal-shaped ring bands. Using novel morphology analyses via 3D-dissection approaches, the lamellae underneath the ridge bands are shown to be all perpendicular to the substrate plane, i.e. normally-oriented with respect to the substrate surface; whereas, the interior lamellae underneath the valley band are all flat-on and horizontal to the substrate plane. Stereo-depiction clearly demonstrates that the interior lamellae are periodically grating architectures with a fixed crossbar pitch of 20–30 μm of the interior lamellar assembly, matching with the optical inter-ring spacing of optical bands. The mechanisms of growth and assembly are probed in detail. [ABSTRACT FROM AUTHOR]

Poly(butylene adipate) (PBA) self‐aggregation into unique periodicity correlating to its interfacial photonic properties is probed in detail. Investigations on the unique periodic morphology and top‐surface and interior architectures in specifically crystallized PBA are focused on its novel photonic patterns with periodic gratings. Detailed analysis of the interior lamellae from ringless to periodically ordered aggregates (crystallized at 33–35 °C vs. Tc = 30 °C) serves as ideal comparisons. Each interior arc‐shape shell is composed of tangential and radial lamellae mutually intersecting at 90o angle. The interior layer thickness in SEM‐revealed arc‐shape shish‐kebab shell is exactly equal to the optical inter‐band spacing (≈6 µm). A 3D assembly mechanism of periodically banded PBA crystals is proposed, where the orderly arrays on top surfaces as well as the interior microstructures of strut‐rib alternate‐layered assembly resemble nature's photonic crystals and collectively account for the interfacial photonic properties in the ring‐banded PBA crystal that is novel and has potential applications in future. [ABSTRACT FROM AUTHOR]

3D morphology of poly(3‐hydroxybutyrate) (PHB), crystallized in the presence of diluents of poly(1,3‐trimethylene adipate) and poly(ethylene oxide), is probed using a novel approach coupled with selective etching. For interpreting the mechanisms of crystal periodic aggregation, various microscopic techniques and synchrotron microbeam X‐ray analysis are used to observe the top surface in connection with the 3D crystal assemblies. Periodic grating architectures, with the cross‐bar pitch exactly matching with the optical band spacing, are proved in banded PHB. The crystals under the ridge branch out to spawn finer crystals orienting/bending horizontally underneath the valley band, repeating till species drainage or impingement. The grating structure in the banded PHB resembles many nature's iridescence crystals and is further proved by photonic reflection results as a critical breakthrough novel finding. [ABSTRACT FROM AUTHOR]

A completely novel 3D dissection approach is taken to re‐investigate high‐density polyethylene (HDPE) crystallized into periodic architectures in a wide range of Tc. This work first discovers that ring bands present in HDPE are crystallized in a quite wide Tc range (90–120 °C) all within regime‐III growth. With further detailed analyses of the top‐surface‐relief patterns and 3D architectures of HDPE spherulites, this work has fully clarified the periodic morphology packed with alternate ways of single‐crystal aggregates in correlation with the optical banding patterns. The proposed assembly mechanism sheds light that the periodic bands are actually composed of a cross‐hatch grating structure in that the alternately perpendicular orientations from the ridge to valley bands being related to the interior radial to tangential lamellae. Such grating architectures in the interiors of HDPE can be viewed as a mimicry resembling shish‐kebab lamellae self‐aligned by Archimedean spiral‐spins from the nucleus center. [ABSTRACT FROM AUTHOR]

Herein, we aim to investigate the influence of the cooling rate from the melt on stereocomplex formation of equimolar blends of enantiomeric star-shaped poly(lactide)s with a dipyridamole core. As evidenced by differential scanning calorimetry, wide-angle X-ray scattering and Fourier-transform infrared spectroscopy, melt cooling of equimolar blends of star-shaped poly(L -lactide) (SSPLLA) and star-shaped poly(D -lactide) (SSPDLA) resulted in the non-crystalline state. A careful analysis of WAXS and FTIR data revealed that the slow-cooled sample (10 °C min−1) exhibited the amorphous phase and the fast-cooled sample (50 °C min−1) resulted in the mesophase. On subsequent heating, the slow-cooled sample remained in the amorphous phase, whereas the fast-cooled sample crystallized (cold crystallization) exclusively into the stereocomplex at ∼90 °C. Aging of the slow-cooled sample at room temperature and subsequent heating led to the formation of the stereocomplex. Photoluminescence studies revealed that the cooling rate from the melt has a strong influence on core molecule (dipyridamole) aggregation and determines the geometry of interactions between the branches of SSPLLA and SSPDLA. In the slow-cooled sample, because of the longer residence time above the glass transition temperature, dipyridamole molecules form aggregated structures, whereas in the fast-cooled sample, dipyridamole molecules are distributed within the polymer matrix without much aggregation. Based on these results, we propose antiparallel chain packing in fast-cooled SSPLLA/SSPDLA blends because of the non-aggregation of dipyridamole core molecules and this geometry favored the exclusive formation of stereocomplex. On the other hand, due to the possible aggregation of dipyridamole molecules, the slow-cooled sample led to topological and geometric constraints where the interactions between SSPLLA and SSPDLA chains prevented the crystallization. The present findings could open new avenues for the design of a variety of macromolecular architectures for a better understanding of the stereocomplex formation mechanism of chiral polymers. [ABSTRACT FROM AUTHOR]

Crystallized poly(nonamethylene terephthalate) (PNT) displays mirror-image and Fermat's-spiral ring-banded spherulites, respectively. The interior anatomy by SEM and AFM microscopic analyses shows that the lamellar arrangement of grating-board structures inside the 3D bulk banded PNT is correlated to top-surface topography of alternate ridge and valley bands. For the banded spherulites, tangential-oriented lamellae under the ridges and radial-oriented lamellae under the valleys are collectively arranged into mirror-image or spiral symmetry, where the tangential lamellae intersect at 90° angle with the branching radial lamellae. Moreover, the grating-layered structures of the tangential lamellae are viewed as the shish-crystals from which the kebab side-branches grow outwards in the radial direction. 3D models are proposed to illustrate the lamellar assemblies in both types of periodic bands. Morphological evolution and lamellar assembly with dual discontinuity are addressed to further establish 3-D models. [ABSTRACT FROM AUTHOR]

Lamellar assembly in unusual sector-face PLLA spherulites from crystallization of poly(l-lactic acid) (PLLA) diluted with amorphous poly(methyl methacrylate) (PMMA). The growth and morphology of the crystalline structures is studied using polarized optical microscopy (POM), atomic-force and scanning electron microscopies (AFM, SEM). Crystals are also analyzed using differential scanning calorimetry (DSC) and small-angle X-ray scattering (SAXS). The two alternate sectored faces differ dramatically in their optical birefringence and top-surface and interior lamellar assembly. By originating from the nucleus center, an explosive fan-like sector of high-birefringence lamellae is packed by fractal growth from an initial single stalk into hundreds of branches upon reaching the periphery, with the number of stalks increasing roughly by the Fibonacci sequence along the radial distance. The exploded pattern resembles a cross-hatch grating structure, and displays a cauliflower-like fractal-branching of optical birefringence blue/orange stripes. This finding suggests that growth with periodic branching is one of the main mechanisms to fill the ever-expanding space in the spherulitic 3D aggregates. [ABSTRACT FROM AUTHOR]

A small-molecule compound, phthalic acid (PA), crystallized in the presence of poly(ethylene oxide) (PEO) with various compositions was utilized as a model to investigate the morphology and crystal assembly of periodically ordered structures in banded spherulites. After etching off PEO from crystallized solids, detailed crystal assembly in PA was analyzed by utilizing atomic-force microscopy (AFM) and scanning electron microscopy (SEM) to reveal the mechanisms of the formation of fractal-shaped banded spherulites. A novel banded pattern with fractal-shaped lamellar structures is found when the composition of PEO is at or above 20%, and this pattern significantly differs from the ordinary extinction–bright banded morphology of neat PA. The diluent PEO is regarded as the main factor in transforming the crystalline morphology from a compact banded pattern to a fractal-shaped banded pattern. The banded spherulites are composed of numerous fractal structures periodically branching out. Each fractal unit contains two portions: a main stalk (ridge) whose discrete crystalline aggregates are arranged along the radial direction and a fern-like dendrite (valley) whose crystals are arranged along the tangential direction. In situ monitoring of the growth process of the fractal-shaped banded spherulites proves the fractal-branching growth mechanism for the formation of banded spherulites. The periodically perpendicular intersection of discrete crystals results in the contrasting birefringence bands of banded spherulites. A periodic grating structure with fractal branching leads to such a novel pattern of banded PA spherulites. [ABSTRACT FROM AUTHOR]

Dendritic spherulites are one type of diversified ways of crystal aggregations into micrometer-size consortia by kinetics-driven assembly from nanometer-size crystal plates (i.e., lamellae or single crystals). Crystallized polymers can exist in states of different degrees of order, which lead to the resulting assembled morphologies are of non-equilibrium supramolecular hierarchical patterns of crystal structures. Diffusion-controlled growth patterns emerge, which change the details of dendritic morphology depending on Tc (degree of super-cooling), polymer-diluent interactions, confinement. Investigation to the diversified patterns of lamellar assembly into polymer dendritic spherulites has come to several key conclusions. This article reviews and summarizes the top-surface-relief morphology and interior dissections of polymer dendritic spherulites, where the dendrites may be composed of ringed stripes or fibrous cilia crystals. The results yield interesting consistency for constructing workable mechanisms to account for each type of morphologies with respect to their molecular weights and crystallization kinetics conditions (i.e., Tc, space confinements, film thickness, blend interaction, as well as blend composition). [ABSTRACT FROM AUTHOR]

Towards the development of new biomaterials for use in angioplasty, star-shaped polylactic acids have been synthesised and shown to adhere well to living cells, by in vitro and in vivo experiments, and to hydrolyse over time in a physiologically relevant environment into biocompatible and bioabsorbable entities that are capable of bestowing properties of anticoagulation and angiogenesis to their living host. [ABSTRACT FROM AUTHOR]

Urethane polymers (PU) have been prepared from low-molecular weight polylactic acid (PLA) and hexamethylene diisocyanate (HMDI) using polydimethylsiloxane (PDMS) as a chain extender. These formed the supporting polymeric matrix of curcumin-containing PU membranes which were prepared using a solvent evaporation technique. FTIR and XRD data indicated the molecular-level dispersion and random distribution of curcumin in the polymer matrix, and data were consistent with observations from tensile-strength measurements and from AFM imaging. Determination of water vapor permeability and moisture uptake measurements have indicated that the PU membrane were appropriate for use on human skin. Skin permeation studies of curcumin were consistent with zero order ( R2 = 0.9874) and with Korsmeyer-Peppas ( R2 = 0.9978) kinetics-analytical data pointed to permeation by a combination of diffusion and erosion processes, with the latter dominating. The biocompatibility of these PU membranes was indicated by in vitro cytotoxicity studies using 3T3-L1-Murine fibroblast cell. The in vitro therapeutic potential of the patches was demonstrated against A549 human Lung cancer cells. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2011. [ABSTRACT FROM AUTHOR]

Amorphous poly(p-vinyl phenol) (PVPh) was added into semicrystalline poly(p-dioxanone) (PPDO) to induce a uniquely novel dendritic/ringed morphology. Polarized-light optical, atomic-force and scanning electron microscopy (POM, AFM, and SEM) techniques were used to observe the crystal arrangement of a uniquely peculiar cactus-like dendritic PPDO spherulite, with periodic ring bands not continuingly circular such as those conventional types reported in the literature, but discrete and detached to self-assemble on each of the branches of the lobs. Correlations and responsible mechanisms for the formation of this peculiar banded-dendritic structure were analyzed. The periodic bands on the top surface and interior of each of the cactus-like lobs were discussed. The banded pattern was composed of feather-like lamellae in random fractals alternately varying their orientations from the radial direction to the tangential one. The tail ends of lamellae at the growth front spawned nucleation cites for new branches; in cycles, the feather-like lamellae self-divided into multiple branches following the Fibonacci sequence to fill the ever-expanding space with the increase of the radius. The branching fractals in the sequence and the periodic ring-banded assembly on each of the segregated lobs of cactus-like dendrites were the key characteristics leading to the formation of this unique dendritic/ringed PPDO spherulite. [ABSTRACT FROM AUTHOR]

Monitoring of nucleus geometry and growth into dual types of periodically ring-banded morphology in poly(nonamethylene terephthalate) (PNT), respectively, Type-1 and Type-2, are done with detailed analyses using polarized-light optical microscopy (POM) in-situ CCD recording; the periodic assembly morphologies are characterized using atomic-force microscopy (AFM) and scanning electron microscopy (SEM). Different annealing treatments (Tmax = 110, 120, 130 °C) are accomplished at a crystallization temperature of 85 °C; effects on the nucleus geometry, number (25–10%) and volume fractions (33–15%) of Type-2 among two types of banded PNT spherulites are expounded. Growth of a specific type of periodically banded PNT spherulite is initiated from either highly elongated sheaf-like or well-rounded nuclei, with the final grown lamellae being self-packed as multi-shell structures. Nucleation geometry and crystallization parameters collectively lead to development of multiple types of banded PNT spherulites of different relative fractions. [ABSTRACT FROM AUTHOR]

Front Cover: In article number 2100202 by Eamor M. Woo and co‐workers, micro‐ and nano‐assemblies in periodically ring‐banded PBA crystal aggregates lead to novel photonic properties never been reported. When fine‐tuned, they display ordered structures on the top surface and in the interior lamellae, growing as rib‐branches from “strut” crystals, forming a grating architecture, interfering with light to produce colorful iridescence patterns (templated into letters NCKU). [ABSTRACT FROM AUTHOR]

B Front Cover b : In article number 2100202 by Eamor M. Woo and co-workers, micro- and nano-assemblies in periodically ring-banded PBA crystal aggregates lead to novel photonic properties never been reported. When fine-tuned, they display ordered structures on the top surface and in the interior lamellae, growing as rib-branches from "strut" crystals, forming a grating architecture, interfering with light to produce colorful iridescence patterns (templated into letters NCKU). [Extracted from the article]

Synchrotron X-Ray Analysis and Morphology Evidence for Stereo-Assemblies of Periodic Aggregates in Poly(3-hydroxybutyrate) with Unusual Photonic Iridescence B Back Cover b : Periodically grating assembly of d-(-)-poly(3-hydroxybutyrate) (PHB) is probed using microscopic techniques with 3D dissection and synchrotron microbeam X-ray analyses. The grating-banded crystals, resembling many of nature's iridescence structures, are evidenced by chromism reflection as a critical breakthrough never before discovered. [Extracted from the article]

B Back Cover b : Novel finding is that periodic ring bands are present in HDPE crystallized in a quite wide Tc range (90-120 °C) all within Regime-III growth. Periodic Assembly of Polyethylene Spherulites Re-Investigated by Breakthrough Interior Dissection Via novel interior 3D dissection reveals that the HDPE bands are structured as Archimedean spirals originating from nucleus into crosslamellar grating architectures, resembling the nature's assembly into photonic crystals. [Extracted from the article]