Uneven Morphology Research Articles

Morphology of Salina offshore (Southern Tyrrhenian Sea)

ABSTRACTIn this paper, we present the first complete morphological map of the Salina offshore at a scale of 1:100,000. The submarine flanks of the Salina edifice extend down to −650 to −1300 m, are steep and characterized by an uneven morphology due to the presence of volcanic and erosive-depositional features. The volcanic features cover ∼30% of the submarine portion and include volcanic cones and bedrock outcrops. The remaining ∼70% is affected by a wide series of erosive-depositional features. Among these, features related to Late Quaternary sea level fluctuations comprise the insular shelf surrounding the island and overlying submarine terraced depositional sequences. Mass-wasting features include landslide scars, channels, fan-shaped deposits and waveforms. The presented map provides useful insights for a better understanding of the morphological evolution of the edifice

Studies on corrosion behavior of 6061 Al—15 vol. pct. SiC(p) composite in HCl medium by electrochemical techniques

The micro-galvanic corrosion of SiC reinforced 6061 Al alloys deprives its potential application in the acidic conditions or at high temperatures. Therefore, the corrosion behavior of 6061 Al—15 vol. pct. SiC(p) composite in HCl medium at different temperatures was studied using electrochemical impedance measurements and potentiodynamic polarization curves. The studies revealed that, on increasing the ionic concentration of the medium and temperature the rate of corrosion also increases. Scanning electron microscopic imaging of polished and immersed sample in the medium showed the smooth and uneven morphology respectively. Activation parameters like energy of activation was calculated from Arrhenius plots. Entropy and enthalpy values were derived from the plots of transition state theory equation.

Infiltrating basal cell carcinoma: a stellate peri-tumor dermatoscopy pattern as a clue to diagnosis.

Background:Infiltrating basal cell carcinoma (BCC) has associated features that may be readily identified using dermatoscopy.Objective:Investigate a stellate dermatoscopy pattern extending from the peripheral margin of infiltrating BCC.Methods:A total of 741 consecutive cases of BCC were assessed retrospectively using non-polarized dermatoscopy. Following histopathologic examination, cases were categorized into six different BCC subtypes. Infiltrating cases numbered 107. This stellate feature was defined as a geometric star shaped pattern extending outwards from the circumferential peripheral edge of the tumor, and identified by white lines, vessels or uneven skin surface morphology. The percentages of infiltrating subtype within the tumor mass and tumor depth were compared, with and without the stellate pattern.Results:Infiltrating BCC displayed the stellate pattern more than other BCC subtypes. Concordance between the two observers was almost perfect for white lines: Kappa coefficient of 0.87 (95% CI: 0.0.79–0.95) P<0.01 and substantial for vessels: Kappa coefficient of 0.71 95% CI: 0.59–0.84) P<0.01. Folds were only recorded in infiltrating cases (n=3). Compared to other BCC subtypes the stellate pattern had a sensitivity of 31.7% and specificity of 94.1%. A higher mean fraction of the tumor mass containing infiltrating subtype was found when comparing stellate pattern observed to stellate pattern not observed (P<0.01). No statistically significant association was found between the tumor depth with and without the stellate pattern.Conclusion:This study found a higher incidence of the stellate pattern within infiltrating BCC compared to the other BCC subtypes. As the percentage of the infiltrating subtype within the tumors increased the incidence of the stellate pattern also increased.

Cause analysis of low frequency vibration of flexible support stator frame for giant hydro generator

There are low frequency horizontal vibration problems in varying degree on the stator frame for operating giant hydro generator unit, those who adopted flexible support. To determine the cause of excessive vibration, the horizontal vibration of the stator frame and core were measured under the operating conditions of variable rotate speed, variable load and variable excitation. The results showed that the low frequency vibration had similar vibration characteristics in each generator unit, that is, the vibration of the stator increased as the excitation increasing and it did not matter to the change of rotate speed and load. This low frequency vibration was obviously caused by the unbalance magnetic pull. Based on the uneven of air gap, which induced by uneven magnetic pole morphology and relative eccentricity of the stator-rotor, low frequency vibration was explained.

Efficacy of larvicidal activity of green synthesized titanium dioxide nanoparticles using Mangifera indica extract against blood-feeding parasites

Titanium dioxide nanoparticles (TiO2 NPs) are considered to be among the best photocatalytic materials due to their long-term thermodynamic stability, strong oxidizing power, and relative non-toxicity. Nano-preparations with TiO2 NPs are currently under investigation as novel treatments for acne vulgaris, recurrent condyloma acuminata, atopic dermatitis, hyperpigmented skin lesions, and other non-dermatologic diseases. The present study was to investigate the acaricidal and larvicidal activity of synthesized TiO2 NPs utilizing leaf aqueous extract of Mangifera indica L. (Anacardiaceae) against hematophagous parasites. The anti-parasitic activity of TiO2 NPs against the larvae of Rhipicephalus (Boophilus) microplus, Hyalomma anatolicum anatolicum and Haemaphysalis bispinosa (Acari: Ixodidae), fourth instar larvae of Anopheles subpictus, and Culex quinquefasciatus (Diptera: Culicidae) were assessed. The green synthesized TiO2 NPs were analyzed by UV-Vis, FTIR, X-ray diffraction (XRD), AFM, SEM, and TEM. The XRD analysis of synthesized TiO2 NPs revealed the dominant peak at 2θ value of 27.81 which matched the 110 crystallographic plane of the rutile structure indicating the crystal structure. The FTIR spectra exhibited a prominent peak at 3,448 cm(-1) and showed OH stretching due to the alcoholic group, and the OH group may act as a capping agent. The SEM images of TiO2 NPs displayed spherical, oval in shape, individual, and some in aggregates. Characterization of the synthesized TiO2 NPs using AFM offered three-dimensional visualization and uneven surface morphology. The TEM micrograph showed agglomerates, round and slight elongation with an average size of 30 ± 5 nm. The maximum efficacy was observed in synthesized TiO2 NPs against the larvae of R. microplus, Hyalomma anatolicum anatolicum, Haemaphysalis bispinosa, A. subpictus, and Culex quinquefasciatus with LC50 value of 28.56, 33.17, 23.81, 5.84, and 4.34 mg/L, respectively. In the present study, a novel, simple, and eco-friendly approach has been suggested to control blood-feeding parasites.

Influence of hydrophobization of the polyazulene ion-to-electron transducer on the potential stability of calcium-selective solid-contact electrodes

We introduce here electrosynthesized polyazulene (PAz) as a new ion-to-electron transducer material in solid-contact ion-selective electrodes (SC-ISEs). It is shown that the neutral form of PAz possesses high hydrophobicity (water contact angle: 126±14°) due to its aromatic carbon structure. This makes PAz attractive as a solid-contact (SC) material in SC-ISEs in combination with its high redox capacitance which is three times higher than for PEDOT-PSS. We have studied the electrochemical stability of PAz in direct contact with aqueous electrolyte solutions and applied it as the SC layer buried under a calcium-selective plasticized poly(vinyl chloride) ion-selective membrane (ISM). It is demonstrated that the hydrophobization of the PAz solid-contact at E≤0.2V significantly improved the potential stability of the calcium-selective SC-ISEs which showed a potential drift of only 0.5mVh−1 when the ISMs were for the first time contacted with 0.1M CaCl2 for 24h. Simultaneous determination of the potential stability and the water uptake with the FTIR-ATR spectroscopy could not clearly prove the correlation between low water content at the PAz/substrate interface and the good potential stability obtained with the pre-hydrophobized SC-ISEs. This is due to the relatively uneven surface morphology of the PAz film making the evanescent standing wave of the IR beam to sense water not only in the PAz transducer layer, but also in the ISM. Hence, it is not possible to distinguish between the distribution of water in the ISM and the PAz solid-contact layer. The new SC material presented here was also characterized with cyclic voltammetry, electrochemical impedance spectroscopy and scanning electron microscopy.

Experimental and Numerical Investigation on Flow Characteristics of a Water Jet Impingement

Water jet impingement on a flat target surface can be seen in cooling and cleaning applications, where the flow velocity, static and dynamic pressures are the three main parameters to be considered. Although the jet impingement is a basic free-surface liquid flow, the understanding of flow characteristics after the impingement is essentially needed to elucidate the flow behaviors and its influences to some specific processes. Therefore, the aim of this study is to investigate the flow characteristics of water jet impingement on a solid surface through the computational fluid dynamics and experiments. An obstacle with different thickness was added into the target surface, representing the uneven morphology of workpiece surface to be cooled or cleaned. The parameters considered were the jet impact angle and obstacle thickness, and the water layer formed radially from the stagnation point was observed and analyzed. According to the results, there was a good agreement between the numerical and experimental findings. The jet impact angle was found to remarkably affect all the performance characteristics examined in this study. The water flow characteristics were found to be changed after the flow impinged and passed over the obstacle. In addition, the static and dynamic pressures caused by the impingement were also presented and discussed.

Development of a Machine Vision System for Solar Wafer Counting

The traditional manual counting wafers leaded to the silicon wafer cracked by operating frequently. Instead of the manual work, this paper proposed a system to counting wafers based on Machine Vision theory and Image Processing algorithm. We designed a counter system and adopted infrared led as parallel illumination source. In image pre-processing, this paper presented a series of algorithms, which contained image smoothing, uneven image correction and image morphology operation. This paper proposed a vertical projection counting based on statistics analysis substitute for the Hough straight lines detection, and the method had been achieved ideal effects by experimental results. DOI : http://dx.doi.org/10.11591/telkomnika.v12i5.5108

Solanum trilobatum extract-mediated synthesis of titanium dioxide nanoparticles to control Pediculus humanus capitis, Hyalomma anatolicum anatolicum and Anopheles subpictus

Titanium dioxide nanoparticles (TiO2 NPs) are widely used in paints, printing ink, rubber, paper, cosmetics, sunscreens, car materials, cleaning air products, industrial photocatalytic processes, and decomposing organic matters in wastewater due to their unique physical, chemical, and biological properties. The present study was conducted to assess the antiparasitic efficacies of synthesized TiO2 NPs utilizing leaf aqueous extract of Solanum trilobatum against the adult head louse, Pediculus humanus capitis De Geer (Phthiraptera: Pediculidae); larvae of cattle tick Hyalomma anatolicum (a.) anatolicum Koch (Acari: Ixodidae), and fourth instar larvae of malaria vector Anopheles subpictus Grassi (Diptera: Culicidae). The green synthesized TiO2 NPs were analyzed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy analysis (EDX), and Atomic force microscopy (AFM). XRD analysis of synthesized TiO2 NPs revealed that the particles were in the form of nanocrystals as evidenced by the major peaks at 2θ values of 27.52°, 36.21°, and 54.43° identified as 110, 101, and 211 reflections, respectively. FTIR spectra exhibited a prominent peak at 3,466cm(-1) and showed OH stretching due to the alcoholic group, and the OH group may act as a capping agent. SEM images displayed NPs that were spherical, oval in shape, individual, and some in aggregates with an average size of 70nm. Characterization of the synthesized TiO2 NPs using AFM offered a three-dimensional visualization and uneven surface morphology. The pediculocidal and acaricidal activities of synthesized TiO2 NPs showed the percent mortality of 31, 42, 63, 82, 100; 36, 44, 67, 89, and 100 at 2, 4, 6, 8, and 10mg/L, respectively, against P. h. capitis and H. a. anatolicum. The average larval percent mortality of synthesized TiO2 NPs was 38, 47, 66, 79, and 100 at 1, 2, 3, 4, and 5mg/L, respectively, against A. subpictus. The maximum activity was observed in the aqueous leaf extract of S. trilobatum, TiO(OH)2 solutions (bulk), and synthesized TiO2 NPs with LC50 values of 35.14, 25.85, and 4.34mg/L; 47.15, 29.78, and 4.11mg/L; and 28.80, 24.01, and 1.94mg/L, and r (2) values of 0.982, 0.991, and 0.992; 0.947, 0.987, and 0.997; and 0.965, 0.998 and 0.985, respectively, against P. h. capitis, H. a. anatolicum, and A. subpictus. This study provides the first report on the pediculocidal, acaricidal, and larvicidal activity of synthesized TiO2 NPs. This is an ideal eco-friendly, novel, low-cost, and simple approach to satisfy the requirement of large-scale industrial production bearing the advantage for the control of P. h. capitis, H. a. anatolicum, and A. subpictus.

Study of Lysozyme-Loaded Poly-L-Lactide (PLLA) Porous Microparticles in a Compressed CO₂ Antisolvent Process.

Lysozyme (LSZ)-loaded poly-L-lactide (PLLA) porous microparticles (PMs) were successfully prepared by a compressed CO2 antisolvent process in combination with a water-in-oil emulsion process using LSZ as a drug model and ammonium bicarbonate as a porogen. The effects of different drug loads (5.0%, 7.5% and 10.0%) on the surface morphology, particle size, porosity, tapped density and drug release profile of the harvested PMs were investigated. The results show that an increase in the amount of LSZ added led to an increase in drug load (DL) but a decrease in encapsulation efficiency. The resulting LSZ-loaded PLLA PMs (LSZ-PLLA PMs) exhibited a porous and uneven morphology, with a density less than 0.1 g·cm−3, a geometric mean diameter of 16.9–18.8 μm, an aerodynamic diameter less than 2.8 μm, a fine particle fraction (FPF) of 59.2%–66.8%, and a porosity of 78.2%–86.3%. According to the results of differential scanning calorimetry, the addition of LSZ improved the thermal stability of PLLA. The Fourier transform infrared spectroscopy analysis and circular dichroism spectroscopy measurement reveal that no significant changes occurred in the molecular structures of LSZ during the fabrication process, which was further confirmed by the evaluation of enzyme activity of LSZ. It is demonstrated that the emulsion-combined precipitation with compressed antisolvent (PCA) process could be a promising technology to develop biomacromolecular drug-loaded inhalable carrier for pulmonary drug delivery.

Bathy-morphological setting of Terceira Island (Azores) after the FAIVI cruise

High-resolution morpho-bathymetric data at 1:200,000 scale obtained during the FAIVI cruise (2011) and the resulting geomorphologic map of the Terceira island offshore area (central Azores, Portugal) are presented for the first time. The uneven morphology around Terceira is primarily related to volcanic features, such as linear and cone-shaped eruptive centres and lava flows. Such features are mostly concentrated on volcanic ridges and are aligned along preferential axes, suggesting a strong interaction between tectonics and volcanic processes. The occurrence of active tectonics is also demonstrated by systems of faults cutting the seafloor to the north, east and south of the island. Mapped erosive-depositional features include an insular shelf located at < 150 m water depth (wd), small landslide headwalls, erosive scarps, channelized features and crescent-shaped bedforms. The presented map may represent the base for a first-order geo-hazard assessment.

The effects of gasification feedstock chemistries on the infiltration of slag into the porous high chromia refractory and their reaction products

Synthetic slags with compositions representative of carbonaceous feedstock derived from coal and petroleum coke were infiltrated into 90%Cr2O3–10%Al2O3 refractory material with a temperature gradient induced along the penetration direction of the slag. Experiments were conducted with a hot-face temperature of 1723K (1450°C) in a CO/CO2 gas mixture with a ratio of 1.8, which corresponded to an approximate oxygen partial pressure of 10−8atm. Interactions between the slags and the refractory produced solid-solution spinel layers on the top interfaces of the refractory samples, whose chemistries reflected the compositions of major constituents of the starting slags. FeCr2O4 formed when samples were infiltrated with slag composition rich in FeO, which was typical for coals derived from eastern USA. (Mg,Fe)Cr2O4 formed when samples were infiltrated with slags, containing considerable concentrations of both MgO and FeO that were common in western US coals. In slags resulted from substituting 50% (by weight) of the coal feedstock by petcoke, similar solid solution phases formed as the pure coal counterparts, but with addition of V2O3, which originated from the petcoke feedstock. The chromium spinel layers, to a reasonable extent, limited infiltration by hindering the slag from flowing into the porous microstructure of the refractory and the formation mechanisms of the product layers were discussed. The Fe(Cr,V)2O4 layer that formed in the presence of petcoke ash exhibited an uneven morphology. As compared to the FeO rich slags, MgO rich slags penetrated further beyond the protective layers and into the refractory. Both of these phenomena could lead to increased refractory spallation rates in actual gasification conditions.

Generation of porous poly-l-lactide microspheres by emulsion-combined precipitation with a compressed CO2 antisolvent process.

An emulsion-combined precipitation of compressed CO2 antisolvent (PCA) process was used to fabricate porous poly-l-lactide (PLLA) microspheres (PLLA PMs). A 24 full factorial experiment was performed to optimize the operating process and analyze the effect of the factors on the size and morphology of the PLLA PMs. An investigation of their in vitro cytotoxicity was also performed. Taking methotrexate (MTX) as a drug model, MTX-loaded PLLA PMs (MTX-PLLA PMs) were fabricated by the optimized process. Drug loading behaviors and in vitro inhibitory activity against A549 lung cancer cells were also evaluated. The resulting PLLA PMs and MTX-PLLA PMs both exhibited a porous and uneven morphology, with a density less than 0.4 g cm-3, a geometric mean diameter (Dg) of 10-25 μm, an aerodynamic diameter (Da) less than 4.7 μm, a fine particle fraction (FPF) of 58-62%, and a porosity of 79-85%, meeting the requirements for pulmonary drug delivery. Various characterizations revealed that no chemical change occurred in the PLLA, while a slight shift in the molecular structure of MTX was observed after the process, as well as a change in its physical state from crystalline to amorphous. No obvious cytotoxicity was detected for the PLLA PMs, and the MTX-PLLA PMs displayed a sustained release profile with an encapsulation efficiency (EE) of 81.6%. The fluorescent MTX-PLLA PMs also revealed that most of the drug was homogeneously distributed inside the matrix. An in vitro antitumor assay indicated that the MTX-PLLA PMs possessed a sustained and improved inhibitory activity compared with the raw MTX. This study demonstrates that the emulsion-combined PCA process has potential for developing a promising inhalable carrier for pulmonary drug delivery.

Reliability Analysis of III-V Solar Cells Grown on Recycled GaAs Substrates and an Electroplated Nickel Substrate

This study involved analyzing the reliability of two types of III-V solar cells: (1) III-V solar cells grown on new and recycled gallium arsenide (GaAs) substrates and (2) the III-V solar cells transferred onto an electroplated nickel (Ni) substrate as III-V thin-film solar cells by using a cross-shaped pattern epitaxial lift-off (CPELO) process. The III-V solar cells were grown on new and recycled GaAs substrates to evaluate the reliability of the substrate. The recycled GaAs substrate was fabricated by using the CPELO process. The performance of the solar cells grown on the recycled GaAs substrate was affected by the uneven surface morphology of the recycled GaAs substrate, which caused the propagation of these dislocations into the subsequently grown active layer of the solar cell. The III-V solar cells were transferred onto an electroplated Ni substrate, which was also fabricated by using CPELO technology. The degradation of the III-V thin-film solar cell after conducting a thermal shock test could have been caused by microcracks or microvoids in the active layer or interface of the heterojunction, which resulted in the reduction of the external quantum efficiency response and the increase of recombination loss.

Microencapsulation of conjugated linolenic acid–rich pomegranate seed oil by an emulsion method

Controlled release of food ingredients and their protection from oxidation are the key functionality provided by microencapsulation. In the present study, pomegranate seed oil, rich in conjugated linolenic acid, was microencapsulated. As encapsulating agent, sodium alginate or trehalose was used. Calcium caseinate was used as the emulsifier. Performances of the two encapsulants were compared in respect of the rate of release of core material from the microcapsules and stability of microcapsules against harsh conditions. Microencapsulation was carried out by preparation of an emulsion containing calcium caseinate as the emulsion stabilizer and a water-soluble carbohydrate (either sodium alginate or trehalose) as the encapsulant. An oil-in-water emulsion was prepared with pomegranate seed oil as the inner core material. The emulsion was thereby freeze-dried and the dried product pulverized. External morphology of the microcapsules was studied under scanning electron microscope. Micrographs showed that both types of microcapsules had uneven surface morphology. Release rate of the microcapsules was studied using UV-spectrophotometer. Trehalose-based microcapsules showed higher release rate. On subjecting the microcapsules at 110 °C for specific time periods, it was observed that sodium alginate microcapsules retained their original properties. Hence, we can say that sodium alginate microcapsules are more heat resistant than trehalose microcapsules.

Morphologic and seismic features of the Gulf of Gökova, SW Anatolia: evidence of strike-slip faulting with compression in the Aegean extensional regime

Recently acquired (2005) multi-beam bathymetric and high-resolution seismic reflection data from the E–W-oriented Gulf of Gokova off SW Anatolia were evaluated in order to assess the uneven seafloor morphology and its evolution in terms of present-day active regional tectonics. Stratigraphically, the three identified seismic units, i.e., the basement, deltaic sediments deposited during Quaternary glacial periods, and modern gulf deposits, are consistent with those observed in previous studies. Structurally, the folds and faults with strike-slip and reverse components have been regionally mapped for the first time. Of these, NE–SW-oriented left-lateral strike-slip faults with compressional components forming the so-called Gokova Fault Zone intersect and displace two WNW–ESE-oriented submarine ridges and deep submarine plains. Thus, strike-slip faults are the youngest major structures in the gulf, and control present-day active tectonism. E–W-oriented folds on the inner and outer shelf, which are generally accompanied by reverse faults, delimit the margins of these submarine ridges, and deform the young basin deposits. These features also reveal the concomitant existence of a compressional tectonic regime. The compressional structures probably represent pressure ridges along left-lateral strike-slip fault segments. However, some E–W-oriented normal faults occur on the northwestern and partly also southern shelf, and along the borders of the adjacent deep submarine plains. They are intersected and displaced by the strike-slip faults. The lower seismicity along the normal faults relative to the NE–SW-oriented strike-slip faults suggests that the former are at present inactive or at least less active.

Cationic fluorinated polyacrylate core‐shell latex with pendant long chain alkyl: Synthesis, film morphology, and its performance on cotton substrates

AbstractWe synthesized a novel cationic fluorinated polyacrylate latex (FLDH) with pendant long chain alkyl by copolymerization of perfluoroalkyl ethyl acrylate, lauryl methacrylate, dimethylaminoethyl methacrylate, and 2‐hydroxypropyl acrylate. FTIR, 1H‐NMR, TEM, DSC, and TGA were used to characterize the as‐prepared FLDH. Then fine morphology, components, and hydrophobicity of films on silicon wafer and cotton substrates were investigated by scanning electron microscope, field emission scanning electronic microscope, atomic force microscope, X‐ray photoelectron spectroscopy (XPS), contact angle meter, etc. Results showed that the FLDH particles had quasi‐spherical core‐shell structure with an average diameter of 144 nm. The core‐shell FLDH film thus had two Tg and its thermal property was improved compared to fluorine‐free acrylate latex. FLDH could form a film on both the cotton fiber and silicon wafer substrate. At an amplification of &lt;60,000 (of the original fiber) and the observation rule (working distance) of &gt;100 nm, FLDH showed a smooth resin film on the treated fabric/fiber surface. However, as the observation rule decreased to 2 nm‐almost a molecular lever‐the FLDH film mostly exhibited an inhomogeneous structure and uneven morphology in its atomic force microscope images. There were many low or high peaks in FLDH topography. Consequently, in 5 μm2 scanning field, the root mean square roughness of FLDH film reached to 0.506 nm. XPS analysis indicated the perfluoroalkyl groups had the tendency to enrich at the surface. In addition, water contact angle of the treated fabric could attain 146.2°. FLDH do not influence whiteness of the treated fabric but will make it slightly stiff at high doses. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci., 2013

Overgrowth of Rhodium on Gold Nanorods

This study focuses on the deposition and growth mode of rhodium (Rh) on gold (Au) seed nanorods (NRs). Using a combination of scanning transmission electron microscopy imaging, energy-dispersive X-ray spectroscopy, and UV–visible absorption spectroscopy, we show that Rh deposition results in an uneven overlayer morphology on the Au NR seeds, with a tendency for Rh deposition to occur preferentially on the Au NR ends. The results suggest that complex and kinetically driven metal–metal interactions take place in this system.

Fabrication of Sn Coatings on Alumina Balls by Mechanical Coating Technique and Relevant Process Analysis

Sn coatings were fabricated by mechanical coating technique for the first time. The coatings were characterized by XRD and SEM, among others. The SEM showed that the coatings had an irregular and uneven morphology. The influence of the rotation speed of planetary ball mill on the evolution and formation of the coatings was also investigated. The results indicated that continuous Sn coatings can be formed under a moderate rotation speed. In other words, the coatings cannot be formed when rotation speed was too high or too low. The evolution of the coatings was examined and discussed. The results showed that it followed the universal evolution law of metal coatings which included four stages. However, the exfoliation of the coatings was not seen even the milling time reached 30 h.

Morphology evolution of immiscible polymer blends as directed by nanoparticle self-agglomeration

This work aims to clarify the effect of nanoparticle self-agglomeration structure on the morphology of polymer blends. The morphology development of polystyrene (PS)/polyamide (PA6) blends with titanium dioxide (TiO2) nanoparticles preferentially localized in the PA6 domains was investigated by means of electron microscopy observation, viscoelastic analysis and selective extraction tests. It was shown that the preferential dispersion of TiO2 leads to a significant reduction of the PA6 continuity in the PS/PA6 blend. The size of the PA6 domain increases gradually with further increasing the nanoparticle loading whereas the co-continuity of the PS/PA6/TiO2 mixture is destroyed by isothermal post-treatments. These experimental results are completely different from those in carbon black, nanoclay or nano-silica-filled immiscible polymer blends. To elucidate the progression to the uneven morphology change, the dynamic process of microfibril break-up and droplet coalescence in the molten PS/PA6/TiO2 mixture was traced in real-time through optical microscopy. It was confirmed that the self-agglomerating pattern of the nanoparticle in the polymer melts plays a key role in directing the morphology evolution of the immiscible polymer blend: unlike the self-agglomeration of carbon black to form three-dimensionally continuous network structure, the TiO2 nanoparticles tend to form separate clusters in the PA6 phase. This prevents PA6 droplets from fusing together to form a continuous network during the coalescence and producing larger PA6 domains at higher TiO2 loads.