Amorphous Pattern Research Articles

Preparation and characterization of spiro-acridine derivative and 2-hydroxypropyl-β-cyclodextrin inclusion complex

The spiro-acridine derivative (E)-1′-(benzylideneamino)-5′-oxo-1′,5′-dihydro-10H-spiro[acridine-9,2′-pyrrole]-4-carbonitrile (AMTAC-01) is a synthetic compound with limited water solubility, which restricts its physiological activities and therapeutic applications. Hence, we investigated the complexation of AMTAC-01 with 2-hydroxypropyl‑β‑cyclodextrin (HPβCD) using the freeze-drying method. Complex formation was characterized by scanning electron microscopy, X-ray diffractometry(XRD), nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, and fluorescence spectrophotometry. Additionally, molecular modeling and phase solubility studies were performed. Molecular modeling demonstrated the most stable inclusion model, and phase solubility studies indicated that AMTAC-01 and HPβCD formed a 1:1 inclusion complex with an apparent stability constant of 1145.3 M − 1. XRD and spectroscopy results suggest intermolecular interactions between AMTAC-01 and HPβCD, with the formation of a 1:1 inclusion complex demonstrating an amorphous pattern and alterations in band distribution intensities compared with free drug.

Ki sambandha hoibe takhon he?: Locating Nachnis in the Societal Margins of Kinship in Rural Bengal

Na_chni na_ch, a dance form of West Bengal, is going through a difficult time in its 500-year history. The woman dancer, who is known as a nachni, performs, often at night, along with her male partner, or rasik. Her life is intricately tied with that of her rasik, which includes her status as a woman performer at public events and the observance of proper rituals upon her death. Caught in a web of exploitation, the nachni essentially has no ‘kin’. Following the work by Inden and Nicholas on Bengali kinship and its categories and meanings within Bengali culture, this article looks at the amorphous pattern of kinship for the marginalized, with a special focus on the daily lives of nachnis. It explores the networks on the margins of kinship in which women performers of this crisis-ridden folk-art form survive.

Molluscum contagiosum chez un adulte immunocompétent : aspect clinique, dermoscopique et histologique (Molluscum contagiosum in an immunocompetent adult: clinical, dermoscopic and histological aspects)

Introduction: The virus that causes molluscum contagiosum is an important human skin disease agent. It is more common in children and immunocompromised people, and less common in immunocompetent adults. Observation: We report the case of a 25 year old patient who has presenting for the past 03 months, multiple, rounded, dome-shaped, pink, waxy papules that are 2-5 mm in diameter on the back and arm sides. The patient reported frequenting traditional Moroccan baths and the use of exfoliating bath gloves. Dermoscopy showed yellowish-white amorphous central polylobular patterns surrounded by vascular structures. These aspects were suggestive of the diagnosis of molluscum contagiosum. The blood test, including HIV serology was negative and histopathology confirmed the diagnosis. Management was based on electrocautery. Discussion: Even if the clinical diagnosis of molluscum contagiosum seems easy, the semiological presentations are very numerous. Dermoscopy therefore occupies a very important place. Conclusion: The occurrence of molluscum contagiosum in an adult should lead to a search for underlying immunosuppression, sexual relations or lifestyle habits. Dermoscopy remains an essential tool in the diagnosis.

Quantum scale biomimicry of low dimensional growth: An unusual complex amorphous precursor route to TiO2 band confinement by shape adaptive biopolymer-like flexibility for energy applications

Crystallization via an amorphous pathway is often preferred by biologically driven processes enabling living species to better regulate activation energies to crystal formation that are intrinsically linked to shape and size of dynamically evolving morphologies. Templated ordering of 3-dimensional space around amorphous embedded non-equilibrium phases at heterogeneous polymer─metal interfaces signify important routes for the genesis of low-dimensional materials under stress-induced polymer confinement. We report the surface induced catalytic loss of P=O ligands to bond activated aromatization of C−C C=C and Ti=N resulting in confinement of porphyrin-TiO2 within polymer nanocages via particle attachment. Restricted growth nucleation of TiO2 to the quantum scale (≤2 nm) is synthetically assisted by nitrogen, phosphine and hydrocarbon polymer chemistry via self-assembly. Here, the amorphous arrest phase of TiO2 is reminiscent of biogenic amorphous crystal growth patterns and polymer coordination has both a chemical and biomimetic significance arising from quantum scale confinement which is atomically challenging. The relative ease in adaptability of non-equilibrium phases renders host structures more shape compliant to congruent guests increasing the possibility of geometrical confinement. Here, we provide evidence for synthetic biomimicry akin to bio-polymerization mechanisms to steer disorder-to-order transitions via solvent plasticization-like behaviour. This challenges the rationale of quantum driven confinement processes by conventional processes. Further, we show the change in optoelectronic properties under quantum confinement is intrinsically related to size that affects their optical absorption band energy range in DSSC.

Transparent flexible heater with nano amorphous pattern

A transparent flexible heater with nano amorphous patterns (TFHAs) was fabricated using a nanofiber mask. Amorphous patterns of 600 nm, which displayed no starburst phenomenon upon illumination, were realized using conventional photolithography. The engraved Ag-paste-filled 100 mm × 100 mm conducting film achieved a transmittance of 89.9% and two-terminal resistance of 9.5 Ω, which improved to 6.4 Ω by poly(3,4-ethylenediosythiophene) (PEDOT) coating. Applying a 12 V bias, TFHAs with PEDOT achieved temperatures of 100 °C within 30 s and withstood up to 15 000 bending cycles with minimal degradation.

DCMS Mo-Se-C solid lubricant coatings – Synthesis, structural, mechanical and tribological property investigation

Mo-Se-C is a very less explored subset of carbon-based transition metal dichalcogenide (TMD-C) nanocomposite coatings but a potential candidate as solid lubricant coatings in aerospace and automotive industries due to excellent frictional stability both in humid air and vacuum conditions. The present work aims at the development and investigation of dc magnetron co-sputtered Mo-Se-C coatings using separate C and MoSe2 targets, as a first step for industrial up-scaling. By varying the applied C power, a carbon content of 44 to 60 at. % was achieved. 50 at. % C was selected for the deposition of coatings with negative substrate bias of 50, 70 and 90 V dc voltage and, for the latter, pulsed dc bias was also applied. Maximum Se/Mo ratio of 1.88 was evaluated by wavelength dispersive spectroscopy (WDS) analysis. After the application of substrate bias, the deposition rate and Se/Mo ratio decreased while higher compactness was observed by scanning electron microscopy (SEM). Mo-Se-C coatings displayed broad amorphous grazing incidence X-ray diffraction patterns. Transmission electron microscopy (TEM) showed MoSe2 platelets randomly oriented in amorphous carbon matrix. X-ray photoelectron spectroscopy (XPS) was not conclusive towards the presence of Mo-C bonds while Raman analysis showed the presence of MoSe2 crystalline peaks. Nano-indentation tests showed an increase in the hardness of coatings deposited under negative substrate bias. Tribological tests were performed in humid air and dry nitrogen. 400C(90V) coating displayed the highest frictional stability in both environments, while the lowest friction coefficient of 0.025 and specific wear rate of 2.4 × 10-8 mm3/Nm were achieved for tests in dry nitrogen.

Central composite designed formulation, characterization and in vitro cytotoxic effect of erlotinib loaded chitosan nanoparticulate system

The most common cause of deaths due to cancers nowadays is lung cancer. The objective of this study was to prepare erlotinib loaded chitosan nanoparticles for their anticancer potential. To study the effect of formulation variables on prepared nanoparticles using central composite design. Erlotinib loaded chitosan nanoparticles were prepared by ionic gelation method using probe sonication technique. It was found that batch NP-7 has a maximum loading capacity and entrapment efficiency with a particle size (138.5 nm) which is ideal for targeting solid tumors. Analysis of variance was applied to the particle size, entrapment efficiency and percent cumulative drug release to study the fitting and the significance of the model. The batch NP-7 showed 91.57% and 39.78% drug release after 24 h in 0.1 N hydrochloric acid and Phosphate Buffer (PB) pH 6.8, respectively. The IC50 value of NP-7 evaluated on A549 Lung cancer cells was found to be 6.36 μM. The XRD of NP-7 displayed the existence of erlotinib in the amorphous pattern. The optimized batch released erlotinib slowly in comparison to the marketed tablet formulation. Erlotinib loaded chitosan nanoparticles were prepared successfully using sonication technique with suitable particle size, entrapment efficiency and drug release. The formulated nanoparticles can be utilized for the treatment of lung cancer.

An efficient electrocatalyst of NiO supported on carbon paper for nonaqueous Li–O2 batteries

A Li–O2 battery has been considered as one of the most promising energy storage systems owing to their ultrahigh theoretical energy densities. However, low energy efficiency (high polarization) during discharge/charge and resulting cycle stabilities have severely limited the development of this type of battery. Here, we demonstrate a simple preparation of NiO supported on carbon paper by dipping carbon paper in Ni acetate solution and heating it to apply NiO directly to the carbon as a cathode material for nonaqueous Li–O2 batteries. The prepared sample was confirmed as the structure of NiO-incorporated carbon using X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (XAS), and high-resolution transmission electron microscopy (HR-TEM) analysis despite amorphous patterns seen in XRD (~ 10% NiO in NiO supported on carbon paper). A Li–O2 cell in which the NiO supported on carbon paper was applied as an electrocatalyst showing an initial ~ 6% increase in energy efficiency and a subsequent 50 cycle retention.

Structural, thermal, rheological and optical properties of poly(lactic acid) films prepared through solvent casting and melt processing techniques

Abstract In this study, structural, thermal, rheological and optical properties of poly(lactic acid) (PLA) films prepared by solvent casting and melt processing were observed and compared, in order to gain a better understanding of processing methods on the properties of the polymer. The structural study revealed that the solvent cast PLA film had a comparatively rough surface when fractured, with longer fibrils and produced strong X-ray diffraction peaks, which suggested different crystalline structures within the film. The melt processed film, on the other hand, appeared to be smooth when fractured and had a broad amorphous X-ray diffraction pattern. Thermal analysis indicated that the solvent cast films tended to form crystalline structure because the cold crystallization temperature was higher for the films prepared by solvent cast method. Both films demonstrated a Newtonian plateau at lower frequency with a zero-shear rate viscosity above 1000 Pa s, and showed a shear thinning behaviour at a higher frequency, with the shear thinning of the solvent cast PLA film being stronger than that of melt processed film. In addition, the structural and molecular changes due to the difference in processing conditions were investigated using polarized light microscopy and synchrotron-FTIR microspectroscopy.

Study on nanomechanical properties of 4H-SiC and 6H-SiC by molecular dynamics simulations

This article aimed to study the nanomechanical properties of silicon carbide under nanoindentation and nanoscratching by the molecular dynamics (MD). First, the MD models were established and experimentally verified. Then, the MD results were used to analyze the subsurface morphology and crystal defects occurring during the processes, which are comparatively difficult to study through experiments. For comparison, the C face and the Si face of 4H-SiC and 6H-SiC were selected for research. The results indicate that 4H-SiC shows greater normal resistance than 6H-SiC for both faces, and the C face may be easier to machine than the Si face for both 4H- and 6H-SiC. In addition, the hexagon amorphous patterns were found in the horizontal cross-sections views after the indentation, which were deemed to make up of two mutually central symmetric triangles. The results show that these amorphous patterns may be caused by the slip systems of 4H-SiC and 6H-SiC, which are mainly take place on the (0001) basal plane and along the <11–20> directions, depending on their special lattice structures. Through MD simulations, the formation mechanism of sub-surface damage of SiC substrates is much clearer.

Extraction, characterization and technological properties of white garland-lily starch

The white garland-lily rhizomes represent a potential source for starch extraction. Thus, the present study aimed to contribute with new data about the starch extraction yield and to characterize the chemical-structural, thermal and technological properties of the white garland-lily starch. The rhizomes harvested in the dry season presented greater starch yields (22.0 g 100 g−1) than in the early summer (6.9 ± 0.5 g 100 g−1) (d.b). The starch presented adequate purity (97.67 g 100 g−1), the granules were flat, with the thickness varying from 2 to 6 μm and length between 12 and 38 μm, and they showed no birefringence. They presented an amylose content of 59.16 g 100 g−1, crystallinity of 19.30% and type B starch. The C13 CP/MAS spectrum presented an amorphous pattern although indicating a transition to type V. This was a product with moderate swelling power and a high gelatinization peak temperature (76.78 °C). The extraction of white garland-lily starch is feasible in the dry season when it has chemical-structural, thermal and technological properties suitable for use in the food industry, related to its high amorphous starch content.

Fabrication of chitosan-bis (4-formyl-2 methoxy phenyl carbonate) Schiff base nanoparticles and evaluation of their antioxidant and anticancer properties.

The present study details on the mechanism of synthesis of bis (4-formyl-2 methoxy phenyl carbonate), using two green reagents dimethyl carbonate and vanillin for application as therapeutic agent. The synthesized FMPC was identified from the 13C nuclear magnetic resonance spectra. The novel modified Schiff base nanoparticles resulted from the crosslinking of FMPC with chitosan were confirmed by cross-polarization magic angle spinning carbon-13 nuclear magnetic resonance spectroscopy. The incorporation of the FMPC was identified from the amorphous X-ray diffraction patterns of C-FMPC-Nps. The thermal stability of the formed nanoparticles was predicted using thermogravimetric analysis. The morphology of the nanoparticles as observed from HRTEM was found to be smooth and spherical in nature. Both FMPC and C-FMPC-Nps showed significant radical scavenging potential and anticancer property. The carbonate ester backbone and the moiety present in chitosan-FMPC-nanoparticles, underwent hydrolysis at the targeted cancer causing microenvironment to release vanillin and chitosan and enhance the anticancer activity. Both FMPC and C-FMPC-Nps exhibits a dose dependent cytotoxicity towards the different cell lines and it was tested with a commercial drug for application studies. Effective synthesis of FMPC, successful incorporation onto chitosan nanoparticles for the formation of C-FMPC-Nps. The formed Schiff base compound proves to have enhanced antioxidant and anticancer efficacy.

SYNTHESIS AND CHARACTERIZATION OF GRAPHENE FROM COCONUT FIBER (COCOS NUCIFERA) AS ANODE MATERIALS FOR LI-ION BATTERY

Synthesis of graphene from coconut fiber conducted in two stages. The first stage is heating the powder of coconut fiber that passes 325 meshes by hydrothermal method at 200o C for 4 hours. Furthermore, the pyrolysis then treated at temperature of 1000° C for 2 hours. The grain size and surface morphology from graphene observed using SEM in the 1000X magnification. From the SEM image of graphene, it shows the pattern of several thick layers build mutual three-dimensional, forming a flake structure. Observations also show stacks of graphene structure with more big flakes forming a thick pallet. Another characterization was performed by using X-ray diffractometer (XRD), Raman Spectrometer and LCR meter. From XRD observation there is an amorphous pattern at the first stage of synthesis, after pyrolysis at 1000o C for 2 hour a peak near 2θ = 24o, 42oand 52o which corresponds to crystal indexes (002), (400) and (511) became visible. The peak at around 1350 cm-1 in the Raman is the D band. The D band is represented defects, like disruption in the sp2 bonding because of heptagon and pentagon rings, vacancies, edge effect, and etc. DC conductivity or bulk electrical conductivity of about 4.6 x 10-3 Scm-1.

RHEED patterns of 3 nm carbon layer coated Si(111) surface using Sputtering

In order to overcome the high cost of SiC substrates, researchers reacted carbon atoms and Si surface to obtain SiC layers on Si substrate since one decade ago. The SiC is the best substrate to grow the graphene. In this work, 3 nm carbon layer was coated on the Si(111) surface using the Sputtering method. After the RCA cleaning process, n-type Si(111) with resistivity 1.5-4.5 Ω.m was put into the load lock chamber then transferred into the deposition chamber after the vacuum condition was attained. The carbon source was evaporated with plasma energy of 150 watts for 3 min to obtain about 3 nm carbon layer on Si(111) surface. The samples were characterized using ex-situ the reflection high energy electron diffraction (RHEED), the scanning electron microscopy (SEM) and the Raman spectroscopy. The sample was annealed at RT-1400°C while the transition of RHEED pattern was observed using the cooled CCD camera. The amorphous pattern appeared at RT-800°C, a combination of dot and ring patterns appeared at 850-1200°C and finally Si(111)-7×7 appeared at over 1200°C. Dot patterns were investigated as SiC structures. From SEM images, it is confirmed that triangle SiC formed on Si(111) surface. In addition formation of SiC on Si(111) was observed by Raman spectroscopy.

The Influence of Alternating Magnetic Field Frequency on Magneto-Thermal Behavior of Mn0.25Fe2.75O4@PANI Material

Mn0.25Fe2.75O4@PANI material has been successfully synthesized using in-situ polymerization method. Meanwhile, Mn0.25Fe2.75O4 nanoparticles based on local sand was synthesized using the coprecipitation method. The Mn0.25Fe2.75O4@PANI sample was characterized using the instrument of X-Ray Diffraction (XRD), Fourier Transform Infrared (FTIR), Transmission Electron Microscopy (TEM), and Magneto-Thermal Test to know the structure of the material, functional group of the material, size morphology of the material, and the specific absorption rate (SAR) value. The XRD pattern of Mn0.25Fe2.75O4@PANI material was dominated by an amorphous structural pattern. The domination of PANI polymer in the Mn0.25Fe2.75O4@PANI material implicated to the decrease in the intensity of Mn0.25Fe2.75O4 nanoparticle peak. The existence of PANI polymer also impacted on the amount of aggregation of the Mn0.25Fe2.75O4 nanoparticles so that the size of the Mn0.25Fe2.75O4 particles increased from 8.4 nm (without PANI) to 30.4 nm (with PANI). Moreover, the test result using magneto-thermal instrument showed that the bigger the frequency of the alternating magnetic field, the obtained SAR value of the Mn0.25Fe2.75O4@PANI material would be bigger as well. For the frequency of 483 and 553 Hz, the SAR values of Mn0.25Fe2.75O4@PANI material was 0.81 and 3.65 W/g, respectively. Based on the SAR results, the Mn0.25Fe2.75O4@PANI material has the potential to be the media of drug delivery for cancer therapy.

Development of an amorphous nanosuspension by sonoprecipitation-formulation and process optimization using design of experiment methodology

A Design of Experiment (DoE) methodology was adopted to investigate and optimize process parameters and formulations variables for preparing an amorphous clotrimazole (CLT) nanosuspension by sonoprecipitation technique. The amorphous nanosuspension can provide a synergistic effect of increase in dissolution velocity and kinetic solubility which can be advantageously used to improve bioavailability of low-solubility drugs. A Box-Behnken design was utilized to study the effect of formulation parameters (drug concentration, polymer concentration, and surfactant concentration) and process parameter (antisolvent: solvent ratio) on particle size, polydispersibility index (PDI), and zeta potential of amorphous CLT nanoparticles. Soluplus® and poloxamer 407 were incorporated in the formulation for steric and electrostatic stabilization respectively. The optimized formulation predicted by the developed model was validated experimentally. The micronized amorphous suspension, micronized crystalline suspension and nanocrystalline suspension were prepared as controls. The optimized amorphous nanosuspension and controls were characterized by differential scanning calorimetry (DSC), X-ray powder diffraction (XRPD) and polarized light microscopy (PLM) techniques. Additionally, in-vitro dissolution studies were performed. The drug concentration, polymer concentration and antisolvent:solvent ratio were found to be statistically significant in impacting critical quality attributes (CQAs) of drug product. The model developed for zeta potential was insignificant at a 95% confidence interval. The DSC, XRPD and PLM results confirmed the amorphization of CLT by sonoprecipitation process. The DSC thermogram did not show any characteristic endothermic peak, XRPD diffractogram showed amorphous halo pattern whereas PLM images did not illustrate birefringence for amorphous CLT nanosuspension. The in-vitro drug dissolution studies demonstrated relatively higher drug dissolution for amorphous CLT nanosuspension compared to controls at both the dissolution media (de-ionized water and pH 7.2 buffer). The sonoprecipitation process was successfully used to produce a stable amorphous nanosuspension with notably enhanced dissolution velocity by evaluating and optimizing critical process and formulation parameters.

Synthesis of a Polyaniline Nanoparticle Using a Solution Plasma Process with an Ar Gas Bubble Channel.

This work researched polymerization of liquid aniline monomer by solution plasma with a gas bubble channel and investigated characteristics of solution plasma and polyaniline (PANI). The injected gas bubble channel in the proposed solution plasma process (SPP) played a significant role in producing a stable discharge in liquid aniline monomer at a low voltage and furthermore enhancing the contact surface area between liquid aniline monomer and plasma, thereby achieving polymerization on the boundary of the liquid aniline monomer and plasma. Solution plasma properties were analyzed with voltage–current, optical emission spectroscopy, and high-speed camera. Conductivity, percentage yield, and firing voltage of PANI nanoparticle dispersed solution were measured. To investigate the characteristics of synthesized PANI nanoparticles, field emission scanning electron microscopy, dynamic light scattering, transmission electron microscopy, selective area electron diffraction (SAED) pattern, Fourier transform infrared spectroscopy (FTIR), gel permeation chromatography, 1H-nuclear magnetic resonance (1H-NMR), and X-ray photo spectroscopy (XPS) were examined. The FTIR, 1H-NMR, and XPS analysis showed the PANI characteristic peaks with evidence that some quinoid and benzene rings were broken by the solution plasma process with a gas bubble channel. The results indicate that PANI nanoparticles have a spherical shape with a size between 25 and 35 nm. The SAED pattern shows the amorphous pattern.

Physicochemical properties of Arenga pinnata (Wurmb.) Merr starch: effect of high-speed jet treatment

ABSTRACT Impact of high-speed jet (HSJ) treatment on morphology, crystalline structure, retrogradation, thermal and rheological properties of Arenga pinnata (Wurmb.) Merr starch (APS) was investigated. Decreasing with the number of HSJ treatment passes were the turbidity values of pastes (long-term retrogradation), the gelatinization enthalpy, and the crystallinity. Scanning electron microscopy showed APS granule structure was degraded into tiny round particle and thin sheet structures. X-ray diffraction illustrated that the C-type X-ray pattern was changed toward a weak A-type X-ray pattern. With further increases in the number of passes, the weak A-type pattern was changed to amorphous pattern. Dynamic oscillation analysis revealed that HSJ treatment significantly altered the viscoelasticity of APS. During a dynamic frequency sweep, G′ values and G″ at 10 Hz decreased from 589.9 Pa (HSJ0) to 194.9 Pa (HSJ8) and from 101.6 Pa (HSJ0) to 24.5 Pa (HSJ8), respectively, implying that HSJ treatment had a great influence on the elasticity of the APS gel. The results indicated that degradation of APS granular and crystalline structure was mainly involved and HSJ treatment was a potential physical modification technique.

Structures of Mixed-Tacticity Polyhydroxybutyrates

In order to provide parameters that can be used to tailor the crystalline and supramolecular structures of pure polyhydroxybutyrate, we synthesized polymers with fractions of meso groups in the range 0.5–1. We confirmed the random polymerization of R and S enantiomers by the catalyst. From X-ray diffractograms, the lattice parameters were determined; they remained constant for the observed range of fractions. We also traced the directional crystallite sizes over tacticity, which change significantly for one unit cell direction. The respective crystalline phase atom fractions were quantified by iteratively fitting amorphous phase diffraction patterns. We found that the crystalline contents of small-crystallite polyhydroxybutyrates have so far been underestimated. X-ray diffraction and transmission electron microscopical observations from polymers with meso group fractions of 0.5 are discussed. To facilitate the quantification of crystalline atom fractions, we refined two accessible infrared absorption spec...

Biomass fly ash and aluminium industry slags-based geopolymers

Geopolymers are a new class of non-Portland cements produced using an alumino-silicate material and an activating solution, which is mainly composed of sodium or potassium and waterglass to be subsequently cured at relatively low temperatures. Those can be formulated by adding natural minerals, waste and/or industrial by-products. The study investigates the microstructural properties of geopolymers synthesized from metakaolin (MK) and the admixture of fly ash (FBA) and aluminium industry slags (AIS) at different ages of curing. Five different geopolymer compositions were prepared and characterized by XRD, ATR-FTIR and SEM/EDS. The study revealed that geopolymeric gels are identified, which show mainly glassy microstructures, in agreement with the X-ray amorphous diffraction patterns, broad FTIR features and confirmed by SEM/EDS, with promising results prior to an industrial scale.