Typical Crystalline Structure Research Articles

Evaluation of the Structural, Physicochemical and Functional Properties of Dietary Fiber Extracted from Newhall Navel Orange By-Products.

Ultrasound-assisted enzymatic treatment was used to treat Newhall navel orange peel and residue, and then the structural, physicochemical and functional properties of extracted soluble dietary fibers (SDF) and insoluble dietary fibers (IDF) were investigated. The structural properties were determined using scanning electron microscopy, X-ray diffraction, FT-IR and monosaccharide composition. Among these dietary fibers, residue-SDF showed a more complex structure, while peel-IDF exhibited a looser structure. Four samples showed representative infrared spectral features of polysaccharides, typical cellulose crystalline structure and diverse monosaccharide composition. Furthermore, residue-IDF exhibited higher oil-holding capacity (2.08 g/g), water-holding capacity (13.43 g/g) and nitrite ion adsorption capacity (NIAC) than other three samples, and residue-SDF showed the highest swelling capacity (23.33 mL/g), cation exchange capacity (0.89 mmol/g) and cholesterol adsorption capacity (CAC) among these dietary fibers. In summary, this study suggests that the residue-SDF and residue-IDF could be used as the ideal dietary fibers for application in the functional food industry.

Synthesis and Characterisation of Zinc-doped Antimony Selenide

Antimony selenide substituted with Sb0.4Se0.6 and doped with zinc at three doping ratios (x=0, 0.01 and 0.03) was prepared via the solid state reaction method. The three prepared compositions were reacted thermally at 400 °C for 3 h. The structure of specimens was characterised via X-ray powder diffractometer to obtain the type of crystalline structure and lattice parameters of the prepared specimens, which showed a polycrystalline, orthorhombic structure. Optical characterisation was then achieved via UV-visible spectroscopy to exhibit the transmittance and reflectance spectra and estimate the band gap values of the prepared compositions. The samples showed high absorption spectra at low wavelengths (from 60% to 90%) and low reflectance values (from nearly zero to 17%). The band gap measurement showed an indirect transition, with values ranging from 1.2 eV to 1.23 eV. The electrical characteristics were represented by DC resistivity measurement at low temperature and AC conductivity measurement against frequency. The compositions showed a semiconducting behaviour in DC resistivity and compatible results in AC conductivity.

Structural and physicochemical properties of pea starch affected by germination treatment

Two pea varieties were used to investigate the changes in the structural and physicochemical properties of pea starch during germination. The results showed that there were more obvious crimples on the surface of the germinated pea starch granules than native starch. Germination treatment led to significant increases in the amylose content and granule size distribution, while volume proportion of germinated pea starch significantly decreased. All the pea starches showed a typical C-type crystalline structure but the relative crystallinity slightly decreased during germination. Compared with the native starches, the light transmittance and absorption capacities of water and oil all firstly increased and then decreased with the increase of germination time. Moreover, there were obvious increases in the peak viscosity, trough viscosity and final viscosity, while the pasting temperature significantly decreased as germination prolonged to 4 d. The gelatinization temperature of pea starch firstly decreased and then increased during germination, while germinated pea starch showed higher gelatinization enthalpy than that of native starch. In conclusion, the structural and physicochemical properties of pea starch could be significantly affected under germination treatment, which may provide a theoretical basis to promote the utilization of germinated pea starch in the food industry.

The effects of cellulose nanocrystal and cellulose nanofiber on the properties of pumpkin starch-based composite films

Pumpkin starch (PS) was extracted from Cucurbita maxima and utilized to prepare films in combination with cellulose nanocrystal (CNC) and cellulose nanofiber (CNF), using a solvent casting strategy. The PS was characterized to contain 26.6% of amylose, exhibiting a “B”-type crystalline structure and high stability against thermal degradation. PS/CNF films showed better thermal stability than PS/CNC films, whereas the CNC was more effective than CNF for enhancing the tensile strength (TS) of the films. The nanocomposite films containing 1% CNC showed the highest TS of 30.32 MPa. Fourier transform infrared spectra revealed stronger hydrogen bonding in the PS/CNC films, likely contributing to the observed high mechanical strength. CNC and CNF both decreased the transparency of PS films, by 5.2% and 13.1%, respectively. Overall, the properties of PS composite films can be effectively modified by incorporating CNC and CNF, as PS/CNC films with high mechanical strength and PS/CNF films with good thermal stability. Our results indicate that PS is a suitable material for CNC/CNF composite film fabrication. These films are expected to be especially useful in food packaging applications.

Preparation of Cellulose Nanoparticles from Foliage by Bio-Enzyme Methods

There are vast reserves of foliage in nature, which is an inexhaustible precious resource. In this study, the chemical components of five foliage types (pine needles, black locust tree leaves, bamboo leaves, elm leaves and poplar leaves) were analyzed, including cellulose content, hemicellulose content, and lignin content. The bio-enzymatic method was then used to prepare cellulose nanoparticles (CNPs) from these five kinds of leaves, and the prepared CNPs were analyzed using TEM, FTIR, FESEM, and XRD. The results showed that the content of hemicellulose in bamboo leaves was the highest, and the lignin content in the other four leaves was the highest. The cellulose content in the five kinds of foliage was arranged from large to small as pine needles (20.5%), bamboo leaves (19.5%), black locust leaves (18.0%), elm leaves (17.6%), and poplar leaves (15.5%). TEM images showed that the CNPs prepared by the five kinds of foliage reached the nanometer level in width and the micrometer level in length; therefore, the CNPs prepared in this study belonged to cellulose nanofibers (CNFs). The results of FTIR and XRD showed that CNFs prepared by the enzyme treatment exhibited a typical crystalline structure of cellulose II. The degree of crystallinity (DOC) of CNFs prepared from pine needle, poplar leaves, and bamboo leaves are 78.46%, 77.39%, and 81.51%, respectively. FESEM results showed that the CNFs prepared from pine needles, poplar leaves and bamboo leaves by enzymatic method presents a three-dimensional (3D) network structure, and their widths are 31 nm, 36 nm, and 37 nm, respectively. This study provides a meaningful reference for broadening the use of foliage types and improving their added value.

Understanding the granule, growth ring, blocklets, crystalline and molecular structure of normal and waxy wheat A- and B- starch granules

Understanding the structural characteristics of starch can help in determining its functional properties and choosing appropriate applications. This work aimed to comprehensively characterize and understand the morphological, crystalline, and molecular structure of the normal and waxy wheat A- and B- starch granules. X-ray diffraction analysis revealed that both normal and waxy wheat A- and B- starch granules have a typical A-type crystalline structure. Additionally, scanning electron microscopy, small-angle X-ray scattering, and Fourier transform infrared spectroscopy analyses showed differences in shape, the thickness of semi-crystalline growth rings, and short-range molecular order of the normal and waxy A- and B- starch granules. The wheat A-starch granules contained lower proportions of A-chains (DP 6–12) and B1- chains (DP 13–24) than those of the wheat B- starch granules. Also, the results revealed that B1-chains (DP 13–24) play an important role in the formation of surface/mass fractal characteristics of starch granules. Furthermore, the atomic force microscopy analysis showed that the normal and waxy wheat A-starch granules are mass fractal, while the normal and waxy wheat B- starch granules are surface fractal.

Preparation and characterization of octenyl succinylated starch microgels via a water-in-oil (W/O) inverse microemulsion process for loading and releasing epigallocatechin gallate

Corn starch (CS), octenyl succinic anhydride modified corn starch (OSCS) and shells (OSCs) microgels have been prepared using water-in-oil (W/O) inverse microemulsions for loading and releasing of epigallocatechin gallate (EGCG). The structural and morphological properties of CS, OSCS, and OSCs microgels were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), Transmission electron microscopy (TEM), and Thermogravimetric analysis (TGA). The strong hydrogen bonds between starch molecules in the W/O system and interplay between hydroxyl groups of EGCG and oxygen atoms of starch microgels were formed. OSCs microgel showed low average particle size and weak thermal stability with an irregular shape and a typical V-type crystalline structure. Encapsulation efficiency (EE) and clearance rate of 2,2-diphenyl-1-picrylhydrazyl (DPPH) for EGCG were ranged between 41.78 and 63.89% and 75.53–85.37%, respectively, when absorbed into OSCS and OSCs microgels, the values which were higher than that of CS microgel. Further, OS starch microgels (particularly OSCs) modulated the slow release of EGCG into simulated gastrointestinal tract conditions and therefore could be proposed as an encapsulating agent for loading polyphenols.

Effect of germination treatment on the structural and physicochemical properties of quinoa starch

Changes in the structural and physicochemical properties of quinoa starch during germination were investigated. The amylose content of Zhongli No.1 quinoa (ZQ) was 17.37%, which was almost 4–5 times greater than the other two genotypes. The surface of germinated quinoa starch granules showed more pinholes and obvious crimples than native starch. The germinated Mengli No. 1 quinoa starch (MQS) and Yunnan red quinoa starch (YQS) had a higher ratio of short chains than native starch, while the opposite result was observed in Zhongli No.1 quinoa starch (ZQS). Germination decreased the relative crystallinity of starch, but it did not change its crystalline structure type. Peak viscosity, trough viscosity, retrogradation enthalpy and the percentage of retrogradation significantly decreased during germination. In conclusion, germination significantly impacted on the structural and physicochemical properties of quinoa starch, which provides a basis for the utilization of germinated quinoa products in the food industry.

Greener synthesis and characterization of cadmium-tellurium quantum dots using aqueous extract of waste orange peel

Cadmium-Tellurium quantum dots are inorganic semiconductor material. In the present study, highly stable Cadmium-Tellurium (CdTe) quantum dots with good optical properties were successfully synthesized by using waste orange peel extract. Fourier-transform infrared spectroscopy (FTIR) identified the presence of hydroxyl, carboxyl and amine groups. Multifunctional X-ray Photoelectron Spectroscopy (XPS) confirmed the presence of cadmium and tellurium. The average size of the quantum dots was found to be 6nm using Transmission Electron Microscopy (TEM). The cubic zinc blende type crystalline structure of quantum dots was confirmed by X-ray powder diffraction (XRD). Thermal stability was studied using thermo-gravimetric analysis (TGA). The influence of temperature with respect to mass change of 8% was observed at 200C. The high luminescence property exhibits at the wavelength of 502 nm were investigated using photoluminescence analysis (PL) and the blue shift is confirmed by UV-Visible spectroscopy.

Vertically arranged Mn2O3 nanosheets as smart sensing electrode for highly sensitive N-hydroxysuccinimide

Vertically arranged manganese (III) oxide (Mn2O3) nanosheets (NSs) thin film was deposited on nickel (Ni) foil through low temperature hydrothermal method and utilized as smart working electrode for N-hydroxysuccinimide (NHS) chemical sensor. FESEM images revealed highly dense nanosheets structures which were vertically arranged on Ni foil. Grown Mn2O3-NSs displayed a typical cubic crystalline structure with good stoichiometric composition of elements. The electrochemical analysis of Mn2O3-NSs/Ni electrode demonstrated a high anodic peak which confirmed a high electrocatalytic activity towards NHS via fast charge transfer process. Mn2O3-NSs/Ni electrode based NHS chemical sensor showed significantly a high sensitivity = ~90μA.μM−1cm−2 and detection limit = ~3.6 μM with a correlation coefficient (R) of ~0.99088 and a short response time (10 s).

Structural Characteristics of a Copper-Nickel Alloy Obtained by Selective Laser Smelting

A three-dimensional model from powders of a copper-nickel alloy Cu81-Ni19 composition is obtained by selective laser smelting. The 3D model microstructure is characterized by the absence of typical crystalline structure and contains elements of a quasi-amorphous state. The finished material differs from the standard monolithic cast billet with a lower surface roughness, higher hardness values while maintaining almost the same density indices.

Ultrastructural features of aporocotylid blood flukes: The tegument and sensory receptors of Sanguinicola inermis Plehn, 1905 from the pike Esox lucius, with a comparative analysis of their traits within the Neodermata

This work represents the first ultrastructural study of the tegument of a freshwater teleost-infecting aporocotylid blood fluke and the first detailed observations of the surface sensory receptors of any aporocotylid. The work was carried out on Sanguinicola inermis from the branchial arteries of the pike, Esox lucius. Light and scanning electron microscopy observations failed to show the presence of protruding surface spines in S. inermis. Transmission electron microscopy studies revealed, deep beneath the distal cytoplasm of the tegument, sporadic, membrane-bound sarcoplasmic processes, each containing a single spine with the typical crystalline structure of digenean spines. On rare occasions, the spine may protrude above the body surface, but in such cases the distal tegumental cytoplasm is extremely flattened. This finding supports a unique, deep origin of aporocotylid spines when compared to those of other digenean families. This character may well prove to be an autapomorphy of the Aporocotylidae, and the position of the base of aporocotylid spines within sarcoplasmic processes supports their origin as a muscle derivative. Unlike other digenean groups, the distal region of the cytoplasmic processes, connecting sunken tegumental perikarya with the syncytial tegumental cytoplasm, is strengthened by peripheral microtubules. Three types of ciliated and three types of non-ciliated sensory receptors were distinguished in the tegument of S. inermis. One of the distinctive features of the ciliated receptors is the unusual position of the basal region of the cilium within a tegumental outgrowth. Such a position has previously been described for certain receptors types in larval and adult schistosomatids and larval diplostomids, suggesting that this feature, in adult worms, might prove to be an apomorphic trait for some or all groups of blood flukes.

Enhanced ultraviolet shielding performances of TiO₂ nanorods in different crystalline structures and illite-loaded composites

With deeper understanding of the harm of ultraviolet (UV) ray radiation, more and more attentions have been paid on developing UV shielding agents with better price-quality ratio. In this article, TiO₂ nanorods with three types of crystalline structures (anatase, brookite, and rutile) and their composites with natural illites were prepared by hydrothermal method under appropriate glycolic acid and pH environment. The resultant samples were analyzed by XRD, SEM, XPS, TEM, UV–vis spectrum and UV aging testing. The results confirm that both the aspect ratio and the crystalline structures of TiO₂ nanorods greatly affect the UV shielding performances of TiO₂ films. Compared with anatase and brookite, rutile TiO₂ nanorods with the best aspect ratio (around 3.5) display the best UV shielding performance. Furthermore, after loaded by natural illite micro-sheets, the illite-TiO2 composites display better UV shielding performance than pure TiO₂ nanorods, due to the physical reflection effect and interfacial coupling effect of illite micro-sheets. When the loading amount ratio reaches to 1:1, the illite-TiO2 composite loaded with rutile TiO₂ nanorods display the best UV shielding performance. And such coating is confirmed to be greatly helpful in protecting cotton fabrics from fractures caused by UV aging. The best illite-TiO2 composite can significantly increases the retention tensile strength of cotton fabrics by 47 % against UV radiation. The resultant novel illite-TiO2 composite provides a promising method to product better UV shielding agents for practical applications, which displays lower cost, nearly non-toxic, better aqueous dispersion, controlled UV–vis spectral characteristics, and higher UV shielding performances.

Conversion of blue emitting thermally stable Ca3Bi(PO4)3 host as a color tunable phosphor via energy transfer for luminescent devices

Eulytite type crystalline structure of Eu3+ activated Ca3Bi(PO4)3 phosphors have been synthesized via solid-state reaction method in an ambient atmosphere. The diffraction pattern of the synthesized phosphor confirmed the formation of pure and single-phase crystalline with a cubic structure of Ca3Bi(PO4)3 microparticles. The SEM image of Ca3Bi(PO4)3 illustrates the growth of heterogeneous microstructures with some agglomeration. The Ca3Bi(PO4)3 host shows the broad emission peak at 434 nm (blue region) under the excitation wavelength of 326 nm ascribing to 3P1→1S0 electronic transition of Bi3+ ions. The Eu3+ activated Ca3Bi(PO4)3 phosphors exhibited intense red emission band centered at λem = 612 nm (5D0 →7F2) at excitation wavelengths of 393 & 465 nm and perceived that the optimized Eu3+ ion concentration is 8.0 mol%. The host blue emission intensity diminished with increasing Eu3+ concentration, whereas the intensity enhanced for the characteristic peaks of Eu3+ ions located in 550–725 nm range under the host excitation wavelength (λex = 326 nm). This suggests that part of host emission energy was transferred to the activator when the host was doped with Eu3+ activator ions. The CIE color coordinates for the Ca3Bi(PO4)3 host lie in the blue region, which has been modulated towards the red region with increasing Eu3+ ions concentration. However, the CIE coordinate values for Eu3+ doped Ca3Bi(PO4)3 phosphor fall in the red region at λex = 393 & 465 nm with high color purity. The average decay time of the optimized phosphor was in the range of milliseconds. The PL intensity persists up to 75.45% at 200 °C that of at ambient temperature, assuring the excellent thermal stability of phosphor. The combination of the above revealed results recommends that Ca3Bi(PO4)3: Eu3+ phosphor can be a probable contestant in near-UV/blue excited luminescent devices.

Effect of different particle size of silica on structure, morphology, and properties of thermoplastic cassava starch

Thermoplastic cassava starch (TPS)/silica (SiO2) composites were prepared through melt-mixing, and the effect of different SiO2 particle size (20 nm, 200 nm, and 23 µm) on the structure, morphology, and properties of TPS/SiO2 composites was investigated. TPS/SiO2 composite containing 200 nm SiO2 has the lowest plasticizing time and torque, and the highest tensile and impact strength. The 23 µm SiO2 particle has the strongest effect on promoting retrogradation of starch, while the 200 nm SiO2 particle could inhibit the retrogradation of starch. TPS/SiO2 composite containing 200 nm SiO2 has the highest thermal stability, resistant water absorption, and light transmittance. The 200 nm SiO2 particle could be uniformly and finely dispersed in the starch matrix, however 20 nm SiO2 particle easily aggregated in TPS. The spherulites size was uniform in TPS/SiO2 composite containing 200 nm SiO2. TPS/SiO2 composite indicates the mixture of A + V types of crystalline structure, and TPS/SiO2 composite containing 23 µm SiO2 had the largest crystal size.

Structural Investigations on Hydrothermally Grown ZnO Nanostructures

This study investigates the influence of aqueous solution molarity on the structural characteristics of zinc oxide (ZnO) grown by hydrothermal method. From the X-ray diffraction (XRD) patterns of the ZnO nanostructures, the diffraction peaks confirm the ZnO hexagonal wurtzite type crystalline structure. To investigate the structural properties of ZnO structures in more detail, we analyze the XRD line profiles of the samples by Warren-Averbach model. Based on the model, the diffraction intensity of the XRD is calculated in Fourier space and the information on the size distribution can be derived. Observing the calculated nanostructure size distribution of the samples, we can see that the breadth of the size distribution function decreases then increases with increasing molarities. Furthermore, the theoretical analyzed results are verified by photoluminescence (PL) measurements and the scanning electron microscope (SEM) images.

(Invited) Controlling the Ordering of Na+ and Vacancy By Ti-Doping in P2-Na0.67Co1-XTixO2 for High Energy and Power Density Cathode Materials in Sodium-Ion Batteries

Sodium-ion batteries (NIBs) for large power sources having kWh or MWh scale of energy are highly interesting alternatives for lithium-ion batteries because of abundant sodium resources in the earth and high chemical similarity between Li and Na ions. However, due to the high atomic weight of Na+ and the low working potential of NIBs, the energy and power densities of NIBs are also required to be improved for wide applications. Despite the similar chemical behavior of Na ions in the rechargeable batteries, the high performance of the active material in NIBs is an essential research- topic for the realization of NIBs. Especially, Na ion having a larger diameter than Li-ion in the P2 type layered structure has a distinct Na+/vacancy ordering behavior presenting multiple voltage plateaus during sodium ion insertion and extraction in the electrochemical cycling. This different behavior from lithium-ion batteries makes the sodium ion diffusion complex in the solid matrix due to the pass-through of various stable Na+/vacancy arrangements. This presentation covers an improvement in the electrochemical performance of the cathode material, Na0.67Co1-xTixO2 having P2 type crystalline structure by using various amounts of Ti doping to control Na/vacancy ordering for mitigating the Na ion diffusion in the solid matrix as well as for extending the de-sodiation range to 4.4 & 4.5 V vs. Na/Na+. The proposed material having Ti doping presents a highly relieved an electrochemical Na+/vacancy ordering behavior from the that of Na0.67Co1-xO2 having a severe capacity loss at high potential because of irreversible phase transitions. In particular, 10 % Ti-doping in the Co content highly advances the cycleability by showing 115 mAh g-1 at the 100th cycle, as well as the rate capability by reaching 108 mAh g-1 at a current density of 1000 mA g-1. The detail diffusion kinetics and phase behaviors from the prepared materials are investigated by a systematic analysis combination comprising TEM, in-situ XRD, and electrochemical methods.

Selective Aerobic Upgrading of Lignin-Derived Compound Using a Recyclable Dual-Functional TPO-Loaded Cu-BTC Catalyst

As oxidative conversion of lignin-derived compound, vanillic alcohol (VA), to vanillin aldehyde (VL) represents as a useful process for lignocellulosic biomass valorization. While catalytic aerobic oxidation by Cu and 2,2,6,6-tetramethylpiperidine 1-oxyl (TPO) with O2 as an oxidant is proposed as a promising oxidative process for VA conversion, this conventional Cu/TPO employs homogeneous Cu ions and TPO, making recovery of homogeneous Cu ion and TPO from reaction media extremely challenging. Herein, Cu species and TPO are integrated into a single heterogeneous catalyst through a co-precipitation method to embed TPO into copper benzene-1,3,5-tricarboxylate (CuBTC) metal organic frameworks (MOFs), forming a bifunctional heterogeneous catalyst. The resulting TPO-embedded CuBTC (TEC) retained the typical octahedral morphology and crystalline structure of CuBTC, while encapsulating TPO within CuBTC. The TEC exhibited higher conversion efficiencies of VA than the simple combination of pristine CuBTC and TPO. A higher TPO embedment in TEC, higher temperature and longer reaction time substantially enhanced VA oxidation, and thus TEC with 12.5 wt% of TPO embedment at 120 °C and 2-h reaction time could achieve CVA > 98%, SVL = 100% and YVL > 98%. The TEC is also proven to be reusable for continuous VA oxidation. These features indicate that TEC is a promising heterogeneous catalyst which incorporates the dual catalytic functions of Cu sites and TPO moieties into a catalytic system to continuously, effectively and selectively oxidize VA to VL.

Changes in the Crystallinity Degree of Starch Having Different Types of Crystal Structure after Mechanical Pretreatment.

This paper examines the effect of mechanical activation on the amorphization of starch having different types of crystalline structure (A-type corn starch; B-type potato starch; and C-type tapioca starch). Structural properties of the starches were studied by X-ray diffraction analysis. Mechanical activation in a planetary ball mill reduces the degree of crystallinity in proportion to pretreatment duration. C-type tapioca starch was found to have the highest degree of crystallinity. Energy consumed to achieve complete amorphization of the starches having different types of crystalline structure was measured. The kinetic parameters of the process (the effective rate constants) were determined. The rate constant and the strongest decline in the crystallinity degree after mechanical activation change in the following series: C-type starch, A-type starch, and B-type starch.

Model of fragile destruction of metal constructions at reduced temperatures

The paper presents the results of studies of metals with different types of crystalline structure in a wide range of low temperatures. Based on the data obtained, a model of brittle fracture of metals at low temperatures is proposed. The relationship between the lattice parameter of metals and the temperature of a viscous-brittle transition is established. A quantum-mechanical simulation of the effect of temperature on the lattice parameter has been carried out. It is shown that a decrease in the lattice parameter is observed with decreasing temperature.