Wide-angle X-ray Diffraction Data Research Articles

Fabrication of CuO nanotubes by electrospinning, metallisation and annealing

A straightforward combined technology of electrostatic spinning and metallisation was developed to produce novel metallic nanotubes and nanofibres. The metals were deposited onto electrospun poly(vinyl alcohol) (PVA) nanofibres as a template by metallisation method. After removal of the nanofibre template by heat treatment at 400°C for 24 h, the fibrous morphologies were satisfactorily conserved, suggesting the successful deposition of metal layer on the surface of nanofibre template. Wide-angle X-ray diffraction data confirmed that the PVA nanofibres metallised with the copper layer of 200 nm clearly showed typical copper crystalline peaks, whereas after calcination of the nanofibre templates, interestingly, new crystalline peaks were observed at 2θ = 32.5°, 35.5°, 38.7°, 48.7°, 53.4° and 58.4°, corresponding to the (1 1 0), (0 0 2), (1 1 1), ( 0 2), (0 2 0) and (2 0 2) reflections, respectively. The resulting metallic nanotubes and nanofibres were found to show a typical CuO crystalline structure.

A Study on the Correlation Between Structure and Hole Transport in Semi‐Crystalline Regioregular P3HT

AbstractA correlation between the hole transport and corresponding structural properties of the bulk regioregular poly(3‐hexylthiophene) (rr‐P3HT) is studied as a function of temperature by the time‐of‐flight (TOF) and wide angle X‐ray diffraction (WAXD) techniques. The thermally‐reversible structural evolution along the (100) and (020) directions in a semi‐crystalline rr‐P3HT can be divided into two distinct temperature regions. At T > 120 °C, a large thermal expansion along the π–π stacking direction in the nanocrystals and a deteriorated ordering in the material result in negative slopes of temperature and electric field dependences of hole mobility. The WAXD data suggest that the hole transport is limited by a decrease in the crystallinity and by an increase in the hopping distance along the π‐π stacking direction, while the Gaussian Disorder Model (GDM) with temperature‐independent parameters cannot be applied. At T < 120 °C, the transport‐related structural changes are negligible and the temperature and electric field dependences of hole mobility can be described by the GDM with constant energetic (σ ∼ 120 meV) and positional disorder parameters (Σ ∼ 3.33). These values suggest that the hole transport is limited by the amorphous phase, as commonly seen in disordered polymers. Moreover, a regiorandom P3HT (rra‐P3HT), which shows a temperature‐independent intermolecular distance of ∼15.3Å, provides a route for separate examination of the amorphous phase in rr‐P3HT.

Deformation and orientation in filled rubbers on the nano‐ and microscale studied by X‐ray scattering

AbstractThe orientation and deformation mechanisms in the filler and in the matrix of filled natural rubber were studied by ultra small‐angle X‐ray scattering (USAXS) and wide‐angle X‐ray diffraction (WAXD) performed on rubber samples stretched in situ. Using model fillers that give a signal in the wide and in the small‐angle region allowed us to correlate the models developed to interpret the USAXS data with the information obtained from the WAXD data. Due to the simple geometries of aragonite and nano‐sized aluminum oxide, which served as model fillers, an analytical description using form factors can well represent the experimental two‐dimensional USAXS data of oriented stretched samples. Besides the study of the filler structure, an attempt was made to resolve the local strain in the matrix. We took advantage of the peculiar property of natural rubber, that is, strain‐induced crystallization, to unravel the matrix strain by measuring the degree of crystallinity. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012

Monitoring of a Calcination Reaction of High Reflective Green-Black (HRGB) Pigments by Using Near-Infrared Electronic Spectroscopy: Calcination Temperature-Dependent Crystal Structural Changes of Their Components and Calibration of the Extent of the Reaction

This paper demonstrates the potential of near-infrared (NIR) electronic spectroscopy in nondestructive monitoring of a chemical reaction of inorganic functional material. For this purpose NIR spectra in the 12,000-4000 cm(-1) region were measured for high reflective green-black (HRGB) pigments (Co(0.5)Mg(0.5)Fe(0.5)Al(1.5)O(4)) calcined at 1000, 1100, and 1200 °C and pigments with the same components as HRGB but calcined at different temperatures (500-900 °C) (hereafter, called "Pigments A") . NIR spectra of their components such as Co(3)O(4), MgO, Fe(2)O(3), and Al(2)O(3) were also measured. The NIR spectra of Pigments A show two major broad bands. One arises from a (4)A(2)→(4)T(1) (T(h)) d-d transition of Co(II) in the 9000-6000 cm(-1) region. The other band in the 12,000-9000 cm(-1) region is assigned to a foot of the charge-transfer (CT) band of Fe(2)O(3). The Co(II) band contains three component bands that are characteristic of a spinel structure. A shoulder arising from (A(1-x)B(x))(Th)(A(x)B(2-x))(Oh)O(4) (A≡Co, Mg, B≡Fe, Al; inverse spinel structure) emerges near 5900 cm(-1) in the spectra of Pigments A calcined in the temperature range of 700-900 °C, indicating that the Pigments A calcined in this temperature range assume an inverse spinel structure. When the calcination temperature is above 1000 °C, the final product, HRGB, is produced. This is confirmed from the fact that HRGB shows peaks characteristic of a spinel structure that have different wavenumbers from those of the corresponding peaks of Pigments A. Wide-angle X-ray diffraction (WAXD) patterns were also measured for HRGB, Pigments A, and their components. Based on the NIR and WAXD data we investigated calcination-temperature-dependent crystal structural changes of the components. We also developed partial least squares (PLS) calibration models for the 9000-6000 cm(-1) region of the NIR spectra of HRGB and Pigments A. The score plot of latent variable (LV) 2 of the calibration model for calcination temperature demonstrates clearly the existence of an intermediate of the calcination reaction, which may be (A(1-x)B(x))(Th)(A(x)B(2-x))(Oh)O(4) (A≡Co, Mg, B≡Fe, Al).

Solid State Self-Assembly Mechanism of RADA16-I Designer Peptide

We report that synthetic RADA16-I peptide transforms to β-strand secondary structure and develops intermolecular organization into β-sheets when stored in the solid state at room temperature. Secondary structural changes were probed using solid state nuclear magnetic resonance spectroscopy (ssNMR) and Fourier transform infrared spectroscopy (FTIR). Intermolecular organization was analyzed via wide-angle X-ray diffraction (WAXD). Observed changes in molecular structure and organization occurred on the time scale of weeks during sample storage at room temperature. We observed structural changes on faster time scales by heating samples above room temperature or by addition of water. Analysis of hydration effects indicates that water can enhance the ability of the peptide to convert to β-strand secondary structure and assemble into β-sheets. However, temperature dependent FTIR and time dependent WAXD data indicate that bound water may hinder the assembly of β-strands into β-sheets. We suggest that secondary structural transformation and intermolecular organization together produce a water-insoluble state. These results reveal insights into the role of water in self-assembly of polypeptides with hydrophilic side chains, and have implications on future optimization of RADA16-I nanofiber production.

Comparative properties of cellulose nano-crystals from native and mercerized cotton fibers

Stable aqueous suspensions of cellulose nano-crystals (CNCs) were fabricated from both native and mercerized cotton fibers by sulfuric acid hydrolysis, followed by high-pressure homogenization. Fourier transform infrared spectrometry and wide-angle X-ray diffraction data showed that the fibers had been transformed from cellulose I (native) to cellulose II (mercerized) crystal structure, and these polymorphs were retained in the nanocrystals, giving CNC-I and CNC-II. Transmission electron microscopy showed rod-like crystal morphology for both types of crystals under the given processing conditions with CNC-II having similar width but reduced length. Freeze-dried agglomerates of CNC-II had a much higher bulk density than that of CNC-I. Thermo-gravimetric analysis showed that CNC-II had better thermal stability. The storage moduli of CNC-II suspensions at all temperatures were substantially larger than those of CNC-I suspensions at the same concentration level. CNC-II suspensions and gels were more stable in response to temperature increases. Films of CNC and Poly(ethylene oxide) were tested. Both CNC-I/PEO and CNC-II/PEO composites showed increased tensile strength and elongation at break compared to pure PEO. However, composites with CNC-II had higher strength and elongation than composites with CNC-I.

Nylon 6-ran-Nylon 4 공중합물 필름의 연신 및 승온에 따른 세 방향의 결정구조 변화

In order to study the crystal structures of Nylon 4 copolymer films by elevating temperature and shooting Xray along the three principal directions (through, edge, and end directions), HT (high temperature) WAXD (wide angle X-ray diffraction) was used. Three conclusions were derived from this work. First, the diffraction intensity of samples was strongest in the edge direction. Also, the diffraction intensity became stronger as the draw ratio increased. Second, the Brill transition appeared at <TEX>$140^{\circ}C$</TEX>, which indicates that two peaks merged into one peak within the X-ray diffraction intensity graph. Finally, after cooling the specimen for 24 hours, the WAXD data returned to the same initial state.

Neutron scattering study of the magnetic microstructure of nanocrystalline gadolinium

We report grain-size-dependent results on nanocrystalline bulk Gd obtained by magnetic small-angle neutron scattering (SANS) and magnetometry. This approach allows one to study systematically how the magnetic microstructure of this rare-earth metal is affected by defects in the atomic microstructure, which are largely present in nanocrystalline materials, predominantly in the form of grain boundaries. The neutron scattering data reveal two types of angular anisotropies in the magnetic-field-dependent scattering cross section that are typically not seen in the coarse-grained polycrystal. In particular, a cloverleaf-shaped anisotropy and an elongation of the scattering pattern in the direction of the applied magnetic field have been detected. While the first result, which is an exceptional finding even in the nanocrystalline state, can be attributed to pronounced spin disorder in the vicinity of the Gd grain boundaries, the second anisotropy is related to spin misalignment due to the random magnetocrystalline anisotropy within the individual crystallites. Furthermore, we have calculated the correlation function of the spin misalignment from the radially averaged data, which gives access to the characteristic length scales on which the magnetization is perturbed by crystal defects. The results of this real-space analysis independently support the findings from magnetometry and field-dependent SANS. Wide-angle x-ray diffraction data indicate that stacking faults may limit the range of spin-misalignment fluctuations due to random anisotropy in this material.

Heteronucleobase-functionalized benzoxazine: synthesis, thermal properties, and self-assembled structure formed through multiple hydrogen bonding interactions

In this study we prepared a new class of thymine (T)-functionalized polybenzoxazine (PBZ) through the Michael addition of T to a new acryloyl-functionalized [(3-phenyl-3,4-dihydro-2H-benzooxazin-6-yl)methyl acrylate]benzoxazine (PA-ac) monomer and subsequent polymerization. We used 1H and 13C nuclear magnetic resonance spectroscopy and Fourier transform infrared (FTIR) spectroscopy to confirm the chemical structure of this new monomer and then employed differential scanning calorimetry (DSC) and FTIR spectroscopy to study the curing behavior of the new PBZ. The presence of the strongly self-complementary, multiply hydrogen-bonded T units in the PBZ matrix significantly enhanced its thermal stability, as evidenced from DSC traces and thermogravimetric analyses. Transition electron microscopy and wide-angle X-ray diffraction data provided evidence for the self-assembly of the PBZ occurring through self-complementary multiple hydrogen bonding of its T units.

Phase Transitions in Prequenched Mesomorphic Isotactic Polypropylene during Heating and Annealing Processes As Revealed by Simultaneous Synchrotron SAXS and WAXD Technique

Time-resolved simultaneous synchrotron small-angle X-ray scattering (SAXS) and wide-angle X-ray diffraction (WAXD) technique was used to investigate the phase transitions in prequenched mesomorphic isotactic polypropylene (iPP) samples during heating and annealing processes, respectively. For the heating process, it is shown that the mesomorphic-to-monoclinic phase transition is relatively faster for the mesomorphic iPP sample obtained with the high quenching rate than that with the low quenching rate. For the former, the stability of α-monoclinic crystals formed during heating is relatively higher. As for the annealing process, WAXD and SAXS data illustrate that the higher the annealing temperature (T(a)), the earlier the mesomorphic-to-monoclinic phase transition occurs. Namely, T(a) controls the phase transition rate. Both heating and annealing processes show that the increase of content of α-monoclinic crystal phase is mainly at the expense of the mesomorphic phase, with the content of amorphous phase almost invariable. The isothermal crystallization kinetics for the prequenched mesomorphic iPP sample was analyzed through the Avrami equation, revealing a two-dimensional crystal growth under the diffusion-limited mechanism.

Crystal Structure Analysis of Poly(l-lactic Acid) α Form On the basis of the 2-Dimensional Wide-Angle Synchrotron X-ray and Neutron Diffraction Measurements

The crystal structure of poly(l-lactic acid) (PLLA) α form has been analyzed in detail by utilizing the 2-dimensional wide-angle X-ray (WAXD) and neutron diffraction (WAND) data measured for the ultradrawn sample. The WAXD data were collected using a synchrotron-sourced high-energy X-ray beam of wavelength 0.328 Å at SPring-8, Japan and the WAND data were measured using a neutron beam of wavelength 1.510 Å with a cylindrical imaging-plate camera of BIX-3 system at Japan Atomic Energy Agency. The initial crystal structure model was extracted successfully by a direct method under the assumption of the space group P212121 using about 700 X-ray reflections observed at −150 °C, the number of which was overwhelmingly large compared with the data reported by the previous other researchers and allowed us to perform more precise structural analysis. The crystal structure model obtained by the direct method was refined so that the best agreement between the observed and calculated integrated intensities was obtained or the reliability factor (R) became minimal: R was 18.2% at −150 °C and 23.2% at 25 °C. The thus-obtained chain conformation took the distorted (10/3) helical form with 21 helical symmetry along the chain axis. However, the symmetrically forbidden reflections 003, 007, 009 etc. were detected in a series of the 00L reflections, requiring us to erase the 21 screw symmetry along the molecular chain. By assuming the space group symmetry P1211, the structural refinement was made furthermore and the finally obtained R factor was 19.3% at −150 °C and 19.4% at 25 °C. Although the structural deviation from the 21 screw symmetry was only slightly, this refined model was found to reproduce the observed reflection profiles well for all the layer lines. The thus X-ray-analyzed crystal structure was transferred to the WAND data analysis to determine the hydrogen atomic positions. The R factor was 23.0% for the 92 observed reflections at 25 °C. The agreement between the observed and calculated layer line profiles was good. In this way the crystal structure of PLLA α form has been established on the basis of both the X-ray and neutron diffraction analyses.

New Aspects Regarding the Structure of Spheroidal Cast Iron Carbon Inclusions Revealed by WAXD Investigations

The paper addresses mainly the atomic structure of the spheroidal carbon inclusions (CIs) from a magnesium treated cast iron. The qualitative phase analysis based on diffraction patterns shows that the CI by-products contain carbon, ferrite and iron oxides. Based on peak angular positions and their half-width at half-intensity, the distances between graphenes and the average height of the graphene stack were calculated. To comply with EN 13005 standard, the calculated results include the extended uncertainties U(95%). The Wide Angle X-ray Diffraction (WAXD) data proves clearly that the CI from the spheroidal cast iron do not have a polycrystalline graphite structure, but rather a turbostratic graphite-like structure with the d(002) surprisingly close to the graphite structure, e.g. to 3.34 Å. If this conclusion is accepted, a new approach of the nucleation and growth mechanisms of the CIs in spheroidal cast irons as turbostratic graphite-like structures should be explored, while the mechanisms based on crystallographic considerations should be revised.

Physico-chemical properties of potato starches

Starches were isolated and characterised from 10 potato cultivars grown under the same conditions (with a commercial starch for reference). The chemical composition revealed some differences amongst the starches with protein ranging from 0.30% to 0.34%, amylose 25.2% to 29.1% and phosphorus 52.6–66.2 mg 100 g −1. High performance size-exclusion chromatography (HPSEC) fractionation of isoamylase debranched amylopectin showed that the amylopectin molecules were less branched and consisted of more B1, but less A-chains, than cereal starches. Gelatinisation onset ( T o), peak ( T p) and conclusion ( T c) temperatures of the native potato starches ranged from 58.7 to 62.5 °C, 62.5 to 66.1 °C and 68.7 to 72.3 °C, respectively, whilst the gelatinisation enthalpies ranged from 15.1 to 18.4 J g −1. The gelatinisation temperatures of the starches increased in common with the amounts of short and intermediate sized amylopectin chains. The 13C magic angle spinning nuclear magnetic resonance ( 13C CP-MAS NMR) and wide angle X-ray diffraction (XRD) data (30.6% ± 0.22% crystallinity on average) showed little variance amongst the samples. Particle sizing results, however, revealed more variance (20.6–30.9 μm mean diameter). Overall, these data reveal the subtleties of cultivar specific variation against a background of constant environmental conditions.

First example of multi-scale reverse Monte Carlo modeling for small-angle scatteringexperimental data using reverse mapping from coarse-grained particles to atoms

We propose a new method for multi-scale reverse Monte Carlo (RMC) modeling ofsmall-angle scattering data using reverse mapping from coarse-grained particles to atoms incases where scale separation cannot be assumed. For efficient RMC analysis for small-anglescattering data, it is important to determine a large scale structure with the lowest possiblecomputing cost. In order to find this large scale structure, a method using coarse-grainedparticles instead of atoms is suitable. As our first example, we examine the structure ofexpanded fluid Hg near the critical point. For this system, small-angle x-ray scattering(SAXS) data and wide-angle x-ray diffraction data (XRD) are observed in the samethermodynamic state. First, RMC analysis using coarse-grained particles for SAXS data isperformed. Second, RMC analysis for SAXS and XRD data is performed withthe replacement of a coarse-grained particle by an ad hoc cluster of several Hgatoms. In the present study, we have determined that the size of one coarse-grainedparticle corresponds to ten Hg atoms. The number density for the coarse-grainedparticles is set to one-tenth the actual number density of atoms and the cutofflength is three times (6.9 Å) that of Hg atoms (2.3 Å). As a result, this approach isfound to be successful and the computing cost of RMC analysis can be reduced.

Competitive Growth of α- and β-Crystals in β-Nucleated Isotactic Polypropylene under Shear Flow

It has been well established that, although both shear flow and β-nucleating agent could separately induce β-crystals in isotactic polypropylene (iPP) in an efficient manner, their combination in fact depressed the content of β-crystals when compared with quiescently crystallized β-nucleated iPP. In the current study, in-situ synchrotron wide-angle X-ray diffraction (WAXD) and small-angle X-ray scattering (SAXS) measurements were performed to investigate this behavior. The WAXD data obtained were quantitatively analyzed to determine the independent contributions of applied shear flow and added β-nucleating agent in terms of nucleation stage and subsequent α- and β-crystal growth stage. In the nucleation stage, the addition of β-nucleating agent increased the amount of β-nuclei, while the application of shear flow and the interactions between shear and β-nucleating agent enhanced the amount of α-nuclei (the amounts of α- and β-nuclei were in the same order of magnitude). As a result, in the initial crystallization, α- and β-crystals grew competitively, causing simultaneously increments of α- and β-crystals. However, in the growth stage, the growth rate of β-crystals was faster than that of α-crystals where the epitaxial growth of β-crystals on α-crystals also occurred (due to more favorable isothermal crystallization temperature for β-crystal growth). Consequently, the content of β-crystals became dominant in the limited growth space; however, it was still less than that formed from the quiescent isothermal crystallization of β-nucleated iPP. As the shear rate increased, more shear-induced α-nuclei were formed, further decreasing the amount of β-crystals. Nevertheless, when shear and β-nucleating agent coexisted, β-crystals emerged earlier than α-crystals. The SAXS results indicated that the combination of shear and β-nucleating agent changed the stacking manner of molecular chains, so that the long period of sheared, β-nucleated iPP was comparable to that of quiescently crystallized iPP.

Novel method for producing amorphous rice flours by milling without adding water

AbstractThe present study investigated a novel milling method for producing amorphous rice starch without adding water. A new type of milling machine was developed (termed the shear and heat milling machine (SHMM)), which is capable of applying mechanical shear and heat during the milling process. The SHMM consisted of a pair of rice mortars attached to a servomotor and a ring heater. The heater was installed on the upper mortar; the temperature of the upper mortar was monitored and controlled by a thermal controller. Wide‐angle X‐ray diffraction (WAXD) analysis was used to determine the crystallinities of starch in rice flour samples produced using the SHMM at different milling temperatures. The WAXD data for milled rice flour that had been heated exhibited no diffraction peaks. This experimental result demonstrates that the developed SHMM produces amorphous rice starch easily by milling with heating without the addition of water. The milling conditions such as the shear and heat applied can be used to control the crystallinity of starch in rice.

Self-Reinforced High-Density Polyethylene Prepared by Low Frequency Vibration-Assisted Injection Molding. II: Microstructure Investigation

Scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and wide angle X-ray diffraction (WAXD) were employed to study the microstructure of self-reinforced high-density polyethylene (HDPE) prepared by conventional injection molding (CIM) and a low frequency vibration-assisted injection molding (VAIM). SEM micrographs following permanganic etching showed the self-reinforcement of HDPE is mainly due to the existence of shish-kebab morphology within the core region for VAIM-processed HDPE samples. Pronounced molecular alignment was identified by the WAXD data. An approximate 9% increase in the crystallinity was confirmed by DSC. Both preferred molecular orientation and increased crystallinity serve to yield stronger VAIM-processed injection moldings.

Controlled crystallization of poly(vinylidene fluoride) chains from mixed solvents composed of its good solvent and nonsolvent

AbstractPoly(vinylidene fluoride) (PVDF) chains with the same expanded state were obtained by dissolving PVDF resin in good solvent. Then, the crystallization of PVDF chains from mixed solvents composed of its good solvent and nonsolvent was investigated. N,N‐dimethylformamide (DMF) and ethanol were used as good solvent and nonsolvent of PVDF, respectively. The crystalline phases of PVDF were characterized by Fourier transform infrared (FTIR) spectroscopy and wide angle X‐ray diffraction (WAXD). For the crystallization of PVDF chains from mixed solvents, low ethanol content favored the formation of β phase, while high ethanol content resulted predominantly in the α phase. Different crystallization morphology was observed from the scanning electron microscopy (SEM) images. The obvious spherulite morphology disappeared with the increase in ethanol content in mixed solvent. According to thermal analyses, the crystallized PVDF from mixed solvents with high ethanol content had lower onset melting temperatures than that from low ethanol content. Smaller lamellar thickness calculated from WAXD data reasoned the low onset melting temperatures. The above results indicated that the crystallization of PVDF chains from mixed solvent was a “controlled” process by ethanol content. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 575–581, 2010

Fabrication of Metallized Electrospun Copper Nanofiber Webs

The conductive metallic nanofibers were prepared by using a combined technology of electrospinning and metallization. The electrospun polyurethane and poly(vinyl alcohol) (PVA) nanofibers are metallized with different thicknesses of metal (Cu, Ni) layer via a metallization. The thickness of the metallic layer, which is ranging from 50 nm to 200 nm, was controlled. The resultant metallized nanofibers are characterized using field emission scanning electron microscopy (FE-SEM), wide angle X-ray diffraction (WAXD), and thermogravimetric analysis (TGA). FE-SEM micrographs demonstrate that the nano-scaled metallic layers are well deposited onto the nanofibers. TGA result indicates that thermal stability of the metallized nanofibers was enhanced due to the barrier effects of the metallic thin layer. WAXD data also confirm that the metallic layers are well deposited onto the nanofibers. Remarkably, the fibrous morphologies were satisfactorily conserved after removal of the nanofiber template by heat treatment at ca. 400 oC for 24 hr., suggesting the successful deposition of metal layer onto the nanofiber template, and thereby resulted in the formation of metallic nanofibers and nanotubes depending on the diameter of electrospun nanofibers and the thickness of the deposited metallic layers in the conductive metallic nanofibers. In addition, it was observed that the metallized nanofibers exhibit higher conductive properties depending on the thickness of the deposited metallic layers.

Morphology of inorganic–organic systems consisting of polyhedral oligomeric silsesquioxanes (POSS) and polyamide 6

AbstractPreparation of inorganic-organic hybrids made of polyhedral oligomeric silsesquioxanes (POSS) and polyamide 6 (PA6) has been attempted either by melt mixing of the two components or by in-situ polymerization of -caprolactam (CL) in presence of POSS. The samples have been characterized by wide angle X-ray diffraction (WAXD) and scanning electron microscopy (SEM) techniques. Specific processing conditions (namely, high T in presence of different shear stresses) have been tested. Two different approaches for melt mixing have been used and the morphology of the corresponding systems compared. The melt-mixed pairs prepared in the microcompounder revealed a coarse phase separation, while those made in a simple mixer did not show any perceivable POSS segregation phenomenon, as evidenced by both WAXD data and SEM investigation. Similarly, the in-situ polymerization of CL in presence of POSS did not result in any POSS self-aggregation in the polyamide matrix, achieving a very fine Si dispersion of nanometric dimensions.