Bamboo Charcoal/Poly(L-lactide) Fiber Webs Prepared Using Laser-Heated Melt Electrospinning

Although several studies have reported that the addition of bamboo charcoal (BC) to polylactide (PLA) enhances the properties of PLA, to date, no study has been reported on the fabrication of ultrafine BC/poly(L-lactide) (PLLA) webs via electrospinning. Therefore, ultrafine fiber webs of PLLA and BC/PLLA were prepared using PLLA and BC/PLLA raw fibers via a novel laser electrospinning method. Ultrafine PLLA and BC/PLLA fibers with average diameters of approximately 1 μm and coefficients of variation of 13–23 and 20–46% were obtained. Via wide-angle X-ray diffraction (WAXD) analysis, highly oriented crystals were detected in the raw fibers; however, WAXD patterns of both PLLA and BC/PLLA webs implied an amorphous structure of PLLA. Polarizing microscopy images revealed that the webs comprised ultrafine fibers with uniform diameters and wide variations in birefringence. Temperature-modulated differential scanning calorimetry measurements indicated that the degree of order of the crystals in the fibers was lower and the molecules in the fibers had higher mobilities than those in the raw fibers. Transmittance of BC/PLLA webs with an area density of 2.6 mg/cm2 suggested that the addition of BC improved UV-shielding efficiencies.

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Blends of Carbohydrate Polymers for the Co-Microencapsulation of Bacillus clausii and Quercetin as Active Ingredients of a Functional Food

Polymers ◽

10.3390/polym14020236 ◽

2022 ◽

Vol 14 (2) ◽

pp. 236

Author(s):

María Z. Saavedra-Leos ◽

Manuel Román-Aguirre ◽

Alberto Toxqui-Terán ◽

Vicente Espinosa-Solís ◽

Avelina Franco-Vega ◽

...

Keyword(s):

Functional Food ◽

Spherical Particles ◽

X Ray Diffraction ◽

Active Ingredients ◽

Scanning Calorimetry ◽

Modulated Differential Scanning Calorimetry ◽

X Ray ◽

Carbohydrate Polymers ◽

Bacillus Clausii ◽

Diffraction Peaks

A functional food based on blends of carbohydrate polymers and active ingredients was prepared by spray drying. Inulin (IN) and maltodextrin (MX) were used as carrying agents to co-microencapsulate quercetin as an antioxidant and Bacillus clausii (Bc) as a probiotic. Through a reduced design of experiments, eleven runs were conducted and characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and modulated differential scanning calorimetry (MDSC). The physical characterizations showed fine and non-aggregated powders, composed of pseudo-spherical particles with micrometric sizes. The observation of rod-like particles suggested that microorganisms were microencapsulated in these particles. The microstructure of the powders was amorphous, observing diffraction peaks attributed to the crystallization of the antioxidant. The glass transition temperature (Tg) of the blends was above the room temperature, which may promote a higher stability during storage. The antioxidant activity (AA) values increased for the IN-MX blends, while the viability of the microorganisms increased with the addition of MX. By a surface response plot (SRP) the yield showed a major dependency with the drying temperature and then with the concentration of IN. The work contributes to the use of carbohydrate polymers blends, and to the co-microencapsulation of active ingredients.

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Fabrication of Porous Bone Scaffolds Using Alginate and Bioactive Glass

Journal of Functional Biomaterials ◽

10.3390/jfb10010015 ◽

2019 ◽

Vol 10 (1) ◽

pp. 15 ◽

Cited By ~ 9

Author(s):

Jonathan Hatton ◽

Graham Roy Davis ◽

Abdel-Hamid I. Mourad ◽

Nizamudeen Cherupurakal ◽

Robert G. Hill ◽

...

Keyword(s):

Bioactive Glass ◽

Pore Size ◽

Composite Scaffold ◽

Average Pore Size ◽

Amorphous Structure ◽

X Ray Diffraction ◽

Scanning Calorimetry ◽

Average Pore ◽

X Ray ◽

Novel Material

Porous composite scaffold using an alginate and bioactive glass ICIE16M was synthesized by a simple freeze-drying technique. The scaffold was characterized using compression testing, Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), X-ray diffraction (XRD), X-ray microtomography (XMT) and scanning electron microscopy (SEM). The bioactivity of the scaffold was evaluated by its ability to form apatite on its surface in simulated body fluid (SBF). The data collected showed evidence that the novel material produced had an appropriate pore size for osteoconduction, with an average pore size of 110 µm and maximum pore size of 309 µm. Statistical analysis confirmed that the glass filler significantly (P < 0.05) increased the collapse yield of the scaffolds compared with pure alginate scaffolds. The ICIE16M glass had an amorphous structure, favorable for bioactivity.

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Structure Evolution of La(OH)3 /Fe Composite during Ball Milling

Journal of Nano Research ◽

10.4028/www.scientific.net/jnanor.65.123 ◽

2020 ◽

Vol 65 ◽

pp. 123-134

Author(s):

Samira Lalaoua ◽

Bouguerra Bouzabata ◽

Safia Alleg ◽

Abedelmalik Djekoun ◽

David Shmool

Keyword(s):

Ball Milling ◽

Milling Time ◽

Magnetic Measurements ◽

Amorphous Structure ◽

Structure Evolution ◽

Vibrating Sample Magnetometer ◽

X Ray Diffraction ◽

Scanning Calorimetry ◽

Composite Powders ◽

X Ray

Fe-10wt% La (OH)3 composite powders have been fabricated by ball milling, under argon atmosphere for milling periods of 0, 5 and 10 h, respectively. Changes in structural, morphological, thermal and magnetic properties of the powders during mechanical alloying and during subsequent annealing have been examined by X-ray diffraction, scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and vibrating sample magnetometer (VSM). XRD results: showed the formation of new phases (Fe and LaFeO3 perovskite) created through the ball milling. The results showed that the crystalline size of ball milled powders decreased with increasing the milling time. In fact, after 10 h of ball milling, La (OH)3 changes from nanostructure in amorphous structure. The magnetic measurements display a distinct saturation magnetization and coercivity.

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Study on Crystallization Characteristic of 3PE Anti-Corrosion Coating for Steel Pipeline

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.287-290.2169 ◽

2011 ◽

Vol 287-290 ◽

pp. 2169-2174

Author(s):

Yi Ping Tang ◽

Zhi Feng Li ◽

Guang Ya Hou ◽

Hua Zhen Cao ◽

Guo Qu Zheng

Keyword(s):

Differential Scanning Calorimetry ◽

Cooling Rate ◽

X Ray Diffraction ◽

Scanning Calorimetry ◽

Modulated Differential Scanning Calorimetry ◽

X Ray ◽

Skin Region ◽

Near Zone ◽

Crystallization Characteristic ◽

Lamella Thickness

Three layers polyethylene (3PE) anti-corrosion coating was widely used in oil or gas transmission pipelines in the world. Special HDPE (SHDPE) was used in the outer layer of 3PE coating, which is very important to the performance of the whole coating system. However, till to now fewer study about SHDPE crystallization have been reported. In this paper, the crystallization characteristic of SHDPE and 3PE coating were investigated by differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD), modulated differential scanning calorimetry (MDSC). The results showed that, the crystallinity and lamella thickness of SHDPE were decreased with the increase of cooling rate in fabrication process. Middle adhesion layer of 3PE coating accelerated nucleation and improved the crystallinity of the near zone PE layer. The skin region of 3PE coating had lowest crystallinity due to the highest cooling rate, and the crystallinity was increased from skin to core region of 3PE coating.

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Structural Insight into Chitosan Supports Functionalized with Nanoparticles

Advances in Materials Science and Engineering ◽

10.1155/2018/3965783 ◽

2018 ◽

Vol 2018 ◽

pp. 1-11 ◽

Cited By ~ 2

Author(s):

J. Lamarra ◽

L. Damonte ◽

S. Rivero ◽

A. Pinotti

Keyword(s):

Cross Section ◽

Principal Component ◽

Amorphous Structure ◽

Homogeneous Distribution ◽

Scanning Calorimetry ◽

Modulated Differential Scanning Calorimetry ◽

Glass Transition Temperatures ◽

Positron Annihilation Lifetime ◽

Structural Insight ◽

Insight Into

The incorporation of suspensions of nanoparticles functionalized with gallic acid (GA) was used as a strategy to obtain nanocomposite active films with different both chitosan : tripolyphosphate (CH : TPP) and nanoparticles:chitosan (N : CH) ratios. The thermal analysis carried out by modulated differential scanning calorimetry (MDSC) allowed observing the shift of an endothermic event towards higher temperatures with a greater N : CH ratio. Analyzing ATR-FTIR spectra through principal component analysis (PCA) can be inferred that the incorporation of the nanoparticles produced a discrimination of the samples into clusters when the region 1400–1700 cm−1 was considered. The decrease in crystalline size with the inclusion of nanoparticles (NA and NB) proved the existence of interactions among CH, TPP, and GA, resulting in a more amorphous structure. The positron annihilation lifetime spectroscopy (PALS) technique was adequate to correlate the glass transition temperatures (Tg) obtained by using the MDSC technique with parameters τ2 and I2 ascribed to the annihilation of positrons in the interface. The cross section of nanocomposites obtained by scanning electron microscopy (SEM) clearly showed a homogeneous distribution of the nanoparticles without aggregation, suggesting their compatibility with the CH matrix. By virtue of the obtained results, the nanocomposites with the greatest nanoparticle proportion and the highest TPP concentration attained significant modifications in relation to CH matrices because of the crosslinking of the biopolymer with GA and TPP.

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Thermal and structural characterization of the ZrO2−x(OH)2xto ZrO2 transition

Journal of Materials Research ◽

10.1557/jmr.2001.0303 ◽

2001 ◽

Vol 16 (8) ◽

pp. 2209-2212 ◽

Cited By ~ 22

Author(s):

E Torres-GarciÁa ◽

A. Peláiz-Barranco ◽

C. Vázquez-Ramos ◽

G. A. Fuentes

Keyword(s):

High Resolution ◽

Metastable Phase ◽

Nitrogen Adsorption ◽

The Other ◽

X Ray Diffraction ◽

Scanning Calorimetry ◽

Modulated Differential Scanning Calorimetry ◽

X Ray ◽

Exothermic Process

The exothermic process that occurs around 700 K during calcination of ZrO2−x(OH)2x, associated with the crystallization of the low-temperature tetragonal metastable phase of ZrO2, was analyzed using x-ray diffraction, high-resolution thermogravimetric analysis (TGA), nitrogen adsorption, and modulated differential scanning calorimetry (MDSC). High-resolution TGA allowed us to determine the water loss, resulting from condensation of OH− groups. The amount was 0.137 wt% in our case, equivalent to 1.7 × 10−2 mol of H2O/mol of ZrO2. That corresponds to about one −OH group per nm2 being lost in that process. By using MDSC we determined that the change in enthalpy (∆Hglobal = −15.49 kJ/mol of ZrO2) was the result of two parallel contributions. One of them was reversible and endothermic (∆Hrev = 0.11 kJ/mol of ZrO2), whereas the other was irreversible and exothermic (∆Hirrev = −15.60 kJ/mol of ZrO2). The variability and magnitude of the exotherm, as well as the fact that the accompanying weight loss is so small, are consistent with a mechanism involving the formation of tetragonal nuclei, rather than global crystallization, and hence depend on the number of nuclei so formed.

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Ultrasonic Welding of Fe78Si9B13 Metallic Glass

Materials Science Forum ◽

10.4028/www.scientific.net/msf.809-810.348 ◽

2014 ◽

Vol 809-810 ◽

pp. 348-353 ◽

Cited By ~ 1

Author(s):

Xiao Cun Song ◽

Zheng Qiang Zhu ◽

Yan Fei Chen

Keyword(s):

Metallic Glass ◽

Metallic Glasses ◽

Elevated Temperatures ◽

Supercooled Liquid ◽

Amorphous Structure ◽

Ultrasonic Welding ◽

X Ray Diffraction ◽

Scanning Calorimetry ◽

Optical Micrograph ◽

Area X

The solid bonds of multi-layer Fe78Si9B13metallic glass foils have successfully been produced by ultrasonic welding technology. The interface of weld joints was investigated by Optical micrograph (OM), scanning electron microscope (SEM) observation, micro-area X-ray diffraction (micro-XRD) and differential scanning calorimetry (DSC) analysis. The results demonstrate that no visible interface and defects were observed and the amorphous structure was maintained. The thermal properties of the joined metallic glasses were the same as that of the parent metallic glass. The formation of joining metallic glasses was attributed to the superplastic flow and the thermal stability at elevated temperatures in the supercooled liquid state. Ultrasonic welding as tack welding proposes an effective method for the preparation of bulk metallic glasses (BMGs) and lays the foundation for its future applications.

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The Influence of Annealing Temperature on Microstructure and Magnetic Properties of Fe74Co3Si8B10Al1Nb4 Amorphous Alloy Ribbons

Atlas Journal of Materials Science ◽

10.5147/ajms.v2i1.122 ◽

2017 ◽

Vol 2 (1) ◽

pp. 44-47

Author(s):

Shih Fan Chen ◽

Chih Yuan Chen ◽

Chien Fan Chiang

Keyword(s):

Magnetic Properties ◽

Amorphous Alloy ◽

Coercive Force ◽

Saturation Magnetization ◽

Melt Spinning ◽

Annealing Temperature ◽

Supercooled Liquid ◽

Amorphous Structure ◽

X Ray Diffraction ◽

Scanning Calorimetry

Multi-component alloy ribbons with a composition of Fe74Co3Si8B10Al1Nb4 were prepared by a single roller melt-spinning method. The alloy had a fully amorphous structure, as determined by X-ray diffraction. The alloy ribbons were annealed for 10 min at temperatures of 350, 400, 450, 500, 550 and 600 oC, respectively. Differential scanning calorimetry curves indicated that the glass transition temperature (Tg) and the supercooled liquid range (ΔTx) of the amorphous alloy ribbon were about 494 oC and 43 oC, respectively. The ribbons showed soft magnetic properties, with a Curie temperature (Tc) at 284 oC, high saturation magnetization (Ms) of 1.18 T, and coercive force (Hc) of 33.66 A/m. In the present study, both saturation magnetization and coercive force of amorphous alloy ribbons increased with increasing the annealing temperature, due to precipitations and growth of α–Fe phase nanocrystals in the amorphous matrix. On the other hand, it was found that the coercive force of alloy ribbons reduced as a consequence of precipitations of Nb3Si phase if the annealing temperature reached 600 oC.

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Microstructural Investigations of Rapidly Solidified Al-Co-Y Alloys

Advances in Materials Science and Engineering ◽

10.1155/2013/163537 ◽

2013 ◽

Vol 2013 ◽

pp. 1-7 ◽

Cited By ~ 3

Author(s):

B. Avar ◽

M. Gogebakan ◽

M. Tarakci ◽

Y. Gencer ◽

S. Kerli

Keyword(s):

Melt Spinning ◽

Alloy System ◽

Supercooled Liquid ◽

Amorphous Structure ◽

Supercooled Liquid Region ◽

Liquid Region ◽

X Ray Diffraction ◽

Scanning Calorimetry ◽

Glass Forming ◽

Rapidly Solidified

The alloys with different compositions in the Al-rich corner of the Al-Co-Y ternary system were prepared by conventional casting and further processed by melt-spinning technique. The microstructure and the thermal behavior of the alloys were analyzed by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and differential thermal analysis (DTA). It was found that only rapidly solidified Al85Co7Y8alloy exhibited the best glass forming ability (GFA) and a fully amorphous structure. Besides, Al85Co13Y2and Al85Co2Y13alloy ribbons were fully crystalline, whereas Al85Co10Y5and Al85Co5Y10alloy ribbons consisted of some crystalline phases within an amorphous matrix. The SEM results showed the same trend that the crystalline phase fraction decreases with the approaching into best glass former. From DSC results, only Al85Co7Y8amorphous alloy exhibited a glass transition temperature (Tg) at 569 K, and its supercooled liquid region (ΔTx=Tx−Tg) was found to be 17 K. Moreover, other calculated GFA parameters for this alloy system were also discussed.

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Preparation, Stabilization and Carbonization of a Novel Polyacrylonitrile-Based Carbon Fiber Precursor

Polymers ◽

10.3390/polym11071150 ◽

2019 ◽

Vol 11 (7) ◽

pp. 1150 ◽

Cited By ~ 11

Author(s):

Huichao Liu ◽

Shuo Zhang ◽

Jinglong Yang ◽

Muwei Ji ◽

Jiali Yu ◽

...

Keyword(s):

Carbon Nanofibers ◽

Carbon Fibers ◽

High Performance ◽

Great Influence ◽

X Ray Diffraction ◽

Scanning Calorimetry ◽

Electrospinning Method ◽

Lower Heat ◽

Group 2

The quality of polyacrylonitrile (PAN) precursor has a great influence on the properties of the resultant carbon fibers. In this paper, a novel comonomer containing the sulfonic group, 2-acrtlamido-2-methylpropane acid (AMPS), was introduced to prepare P(AN-co-AMPS) copolymers using itaconic acid (IA) as the control. The nanofibers of PAN, P(AN-co-IA), and P(AN-co-AMPS) were prepared using the electrospinning method. The effect of AMPS comonomer on the carbon nanofibers was studied using scanning electron microscopy (SEM), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and Raman spectrum. The structural evolutions of PAN-based nanofibers were quantitatively tracked by FTIR and XRD during the thermal oxidative stabilization (TOS) process. The results suggested that P(AN-co-AMPS) nanofibers had the lower heat release rate (ΔH/ΔT = 26.9 J g−1 °C−1), the less activation energy of cyclization (Ea1 = 26.6 kcal/mol and Ea2 = 27.5 kcal/mol), and the higher extent of stabilization (Es and SI) during TOS process, which demonstrated that the AMPS comonomer improved the efficiency of the TOS process. The P(AN-co-AMPS) nanofibers had the better thermal stable structures. Moreover, the carbon nanofibers derived from P(AN-co-AMPS) precursor nanofibers had the better graphite-like structures (XG = 46.889). Therefore, the AMPS is a promising candidate comonomer to produce high performance carbon fibers.

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