scholarly journals Electrospun Sodium Alginate/Polyethylene Oxide Fibers and Nanocoated Yarns

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
C. Hu ◽  
R. H. Gong ◽  
F. L. Zhou
Keyword(s):  
Tensile Strength ◽  
Sodium Alginate ◽  
Polyethylene Oxide ◽  
Chemical Properties ◽  
Synthetic Polymer ◽  
Electrospun Fibers ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Hybrid Yarn ◽  
And Chemical Properties

Sodium alginate (NaAlg), as a natural biopolymer, was electrospun from aqueous solution via blending with a biofriendly synthetic polymer polyethylene oxide. The morphology and chemical properties of resultant alginate-based nanofibers were characterized by using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), powder X-ray diffractometer (PXRD), and differential scanning calorimetry (DSC). At a wide voltage window (i.e., 12–24 kV), smooth and uniform nanofibers were obtained from the 5.0% concentration with the NaAlg/PEO ratio ranging from 1 : 1 to 1 : 3. The results from FTIR, PXRD, and DSC demonstrate that molecular interaction exists between these two polymers and, therefore, contributes to the alteration of crystallinity of electrospun fibers. In addition, NaAlg/PEO nanofiber-coated polylactic acid (PLA) yarns with different twist levels were also fabricated in this work. The results show that the tensile strength of the nanocoated hybrid yarn and the tensile strength of uncoated yarn increase with the twist per centimeter (TPC) up to 0.5 but decrease when TPC is further increased. The tensile properties of hybrid yarn are superior to those of the uncoated yarn.

Glass-Ceramics Obtained from Sewage Sludge and its Characteristics Affected by Alkalinity

2014 ◽  
Vol 937 ◽  
pp. 70-73
Author(s):  
Di Wu ◽  
Jun Zhang ◽  
Xing Wang Wen ◽  
Hui Ling Liu
Keyword(s):  
Sewage Sludge ◽  
Raw Materials ◽  
Glass Ceramics ◽  
Chemical Properties ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Sludge Disposal ◽  
Physical And Chemical ◽  
And Chemical Properties

Sewage sludge was tested as component for producing glass-ceramics with the addition of analytic reagent CaO to solve the sewage sludge disposal problems. The effect of alkalinity (Ak=mCaO/mSiO2) on the characteristics of the glass-ceramics was investigated. Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) were used to investigate thermal behavior and crystalline phase of the samples. It was found that the degree and characteristics of crystals in vitrified sludge significantly correlate to the alkalinity of the raw materials. The glass-ceramics with Ak = 0.36 possessed the best physical and chemical properties.

scholarly journals Effect of the Iron Reduction Index on the Mechanical and Chemical Properties of Continuous Basalt Fiber

Materials ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2472 ◽  
Author(s):  
Lida Luo ◽  
Qichang Zhang ◽  
Qingwei Wang ◽  
Jiwen Xiao ◽  
Jin Liu ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Iron Reduction ◽  
Basalt Fiber ◽  
Chemical Properties ◽  
Aluminosilicate Glass ◽  
Photometric Method ◽  
X Ray ◽  
Iron Redox ◽  
And Chemical Properties ◽  
Redox Index

Basalt glass belongs to the iron-rich aluminosilicate glass system; thus, the iron content and the iron redox index (IRI=Fe2+/Fetotal) influence the viscosity, density, mechanical and chemical properties of basalt fiber (BF). In this work, continuous BFs with IRIs ranging from 0.21–0.87 were prepared by adding a different amount of redox agents. An economical and easily accessible testing method—the spectral photometric method with 1,10-phenanthroline—is applied to measure the IRI with convinced accuracy, which has been approved by Mössbauer spectra and X-ray fluorescence analysis. The tensile strength of the BF samples increases approximately linearly with increasing IRI as a function of σ = 227.9 IRI + 780.0 . The FT-IR results indicate that, with increasing IRI, the ferric ions are replaced by the much stronger network formers (Al3+ and Si4+), hence the increased the tensile strength. The X-ray diffraction results show an amorphous nature of BF samples. Moreover, the tensile strength is significantly decreased after the alkali corrosion, which is partly attributed to the severe surface damaging according to the SEM results. This work proved the feasibility of mechanical property improvement in BF production by controlling the iron redox index.

scholarly journals Formulation and Optimization of Sodium Alginate Polymer Film as a Buccal Mucoadhesive Drug Delivery System Containing Cetirizine Dihydrochloride

Pharmaceutics ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 619
Author(s):  
Krisztián Pamlényi ◽  
Katalin Kristó ◽  
Orsolya Jójárt-Laczkovich ◽  
Géza Regdon
Keyword(s):  
Drug Delivery ◽  
Tensile Strength ◽  
Sodium Alginate ◽  
Drug Delivery System ◽  
Delivery System ◽  
Polymer Films ◽  
Hydroxypropyl Methylcellulose ◽  
Chemical Properties ◽  
Active Pharmaceutical Ingredient ◽  
Swallowing Problems

Currently, pharmaceutical companies are working on innovative methods, processes and products. Oral mucoadhesive systems, such as tablets, gels, and polymer films, are among these possible products. Oral mucoadhesive systems possess many advantages, including the possibility to be applied in swallowing problems. The present study focused on formulating buccal mucoadhesive polymer films and investigating the physical and physical–chemical properties of films. Sodium alginate (SA) and hydroxypropyl methylcellulose (HPMC) were used as film-forming agents, glycerol (GLY) was added as a plasticizer, and cetirizine dihydrochloride (CTZ) was used as an active pharmaceutical ingredient (API). The polymer films were prepared at room temperature with the solvent casting method by mixed two-level and three-level factorial designs. The thickness, tensile strength (hardness), mucoadhesivity, surface free energy (SFE), FTIR, and Raman spectra, as well as the dissolution of the prepared films, were investigated. The investigations showed that GLY can reduce the mucoadhesivity of films, and CTZ can increase the tensile strength of films. The distribution of CTZ proved to be homogeneous in the films. The API could dissolve completely from all the films. We can conclude that polymer films with 1% and 3% GLY concentrations are appropriate to be formulated for application on the buccal mucosa as a drug delivery system.

Monitoring of Fluctuations in the Physical and Chemical Properties of a High-Calcium Fly Ash

1987 ◽  
Vol 113 ◽  
Author(s):  
Scott Schlorholtz ◽  
Ken Bergeson ◽  
Turgut Demirel
Keyword(s):  
Fly Ash ◽  
Chemical Properties ◽  
Operating Conditions ◽  
Physical And Chemical Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Morphological Studies ◽  
High Calcium ◽  
Physical And Chemical ◽  
And Chemical Properties

ABSTRACTThe physical and chemical properties of fly ash produced at Ottumwa Generating Station have been monitored since April, 1985. The fly ash is produced from burning a low sulfur, sub-bituminous coal obtained from the Powder River Basin near Gillette, Wyoming. One-hundred and sixty samples of fly ash were obtained during the two year period. All of the samples were subjected to physical testing as specified by ASTM C 311. About one-hundred of the samples were also subjected to a series of tests designed to monitor the self-cementing properties of the fly ash. Many of the fly ash samples were subjected to x-ray diffraction and fluorescence analysis to define the mineralogical and chemical composition of the bulk fly ash as a function of sampling date. Hydration products in selected hardened fly ash pastes, were studied by x-ray diffraction and scanning electron microscopy. The studies indicated that power plant operating conditions influenced the compressive strength of the fly ash paste specimens. Mineralogical and morphological studies of the fly ash pastes indicated that stratlingite formation occurred in the highstrength specimens, while ettringite was the major hydration product evident in the low-strength specimens.

Identification of Amber and the Copal under Heat Pressurized Process

2012 ◽  
Vol 554-556 ◽  
pp. 2112-2115
Author(s):  
Hui Li ◽  
Xuan Wang ◽  
Yong Zhu ◽  
Qin Ren
Keyword(s):  
Chemical Properties ◽  
Peak Position ◽  
Exothermic Peak ◽  
Endothermic Peak ◽  
Scanning Calorimetry ◽  
Natural Resin ◽  
Before And After ◽  
Artificial Heat ◽  
Physical And Chemical ◽  
And Chemical Properties

Amber and copal belong to the natural resin, which are similar and transitional in the physical and chemical properties. The artificial heat-pressurized treatment is contributed to the polymerization of the natural copal, and turns into green, yellow-green and deep orange-yellow copal. It is very difficult to identify amber from the heat- pressurized treatment copal only based on the gemological parameters.The thermal behavior of amber and the copal before and after heat-pressurized treatment were analyzed by means of differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy(FTIR) and nuclear magnetic resonance(NMR). The results show that amber exists an evident endothermic peak around 123~132°C, and copal reveals an obvious endothermic peak at about 174~178°C, and the heat pressurized treatment copal occurs a clear exothermic peak around 150~152°C. The differences between endothermic or exothermic transition and peak position reveal occurring thermal oxidation or the bond breaking or the melting, which are of great significance in the identification.

scholarly journals PHYSICAL AND CHEMICAL STUDIES OF OVERROOF ROCKS OF CLAY SHALES OF THE DZHERDANAK DEPOSIT

2021 ◽  
pp. 16-21
Keyword(s):  
Electron Microscopy ◽  
Fine Structure ◽  
Chemical Properties ◽  
Mineralogical Composition ◽  
Physical And Chemical Properties ◽  
X Ray ◽  
Clay Shales ◽  
Chemical Studies ◽  
Physical And Chemical ◽  
And Chemical Properties

The purpose of this study is study of the physical and chemical properties of the overburden of the Dzherdanak deposit. The chemical and mineralogical composition of the overburden of the Djerdanak deposit has been studied by the methods of X-ray and thermography, electron microscopy and infrared spectroscopy. The main phases are quartz, kaolinite and muscovite. The study of the fine structure of the rock under an electron microscope showed the homogeneity of the rock with pronounced uniform inclusions, which is preserved even after firing. Changes in the rock after firing at 1050 °C have been determined. The formation of mullite at this temperature has been established.

Carbon Nanotube Composites

2019 ◽  
Vol 23 ◽  
pp. 75-81
Author(s):  
Ponnusamy Senthil Kumar ◽  
G. Janet Joshiba
Keyword(s):  
Carbon Nanotubes ◽  
Tensile Strength ◽  
Carbon Nanotube ◽  
Chemical Properties ◽  
Market Demand ◽  
Size Dependent ◽  
Nanotube Composites ◽  
Carbon Nanotube Composites ◽  
Physical And Chemical ◽  
And Chemical Properties

The discovery of carbon nanotubes is one of the remarkable achievement in the field of material science and it is a great advancement of Nanotechnology. A carbon nanotube is an expedient material used in several domains and paves way for the welfare of humans in many ways. Carbon nanotubes are nanosized tubes made from graphitic carbons and it is well known for its exclusive physical and chemical properties. The market demand for the nanotubes has increased progressively due to its size dependent, structure and mechanical properties. The carbon nanotubes possess high tensile strength and it is also found to be the durable fibre ever known. It is also found to possess exceptional electrical properties. The carbon nanotube composites have an excellent young’s modulus and higher tensile strength same as graphite carbon. This review plots the properties of carbon nanotubes and portrays the planning and properties of carbon nanotube composites. The wide application of carbon nanotube composites is also explained.

scholarly journals Fracture analysis and countermeasures of the grid switch castings

2020 ◽  
Vol 165 ◽  
pp. 06015
Author(s):  
Chao Feng ◽  
Siyuan Yang ◽  
Qiao Li ◽  
Mengbao Zhou ◽  
Songqi Wu ◽  
...  
Keyword(s):  
Chemical Properties ◽  
Fracture Analysis ◽  
Casting Defects ◽  
Physical And Chemical Properties ◽  
Direct Reading ◽  
X Ray ◽  
Detection Technology ◽  
Two Stages ◽  
Physical And Chemical ◽  
And Chemical Properties

Based on the detection technology of direct reading spectrum, metallographic microscope and X-ray, the defects of the grid switch castings were analyzed. The four main forms of casting fracture were summarized as poor physical and chemical properties, material misuse, casting defects and designing defects. In order to strengthen the quality control of the source of the product, it was proposed to carry out targeted network inspection in the two stages of material arrival and infrastructure acceptance.

Stereocomplex electrospun fibers from high molecular weight of poly(L-lactic acid) and poly(D-lactic acid)

2020 ◽  
Vol 40 (2) ◽  
pp. 136-142 ◽  
Author(s):  
Homa Maleki ◽  
Hossein Barani
Keyword(s):  
Molecular Weight ◽  
Lactic Acid ◽  
Thermal Properties ◽  
High Molecular Weight ◽  
Chemical Properties ◽  
Electrospun Fibers ◽  
Scanning Calorimetry ◽  
Force Microscopy ◽  
Atomic Force ◽  
Electrospinning Method

AbstractThe stereocomplex formation is a promising method to improve the properties of poly(lactide) (PLA)-based products due to the strong interaction of the side-by-side arrangement of the molecular chains. Recently, electrospinning method has been applied to prepare PLA stereocomplex, which is more convenient. The objective of the current study is to make stereocomplexed PLA nanofibers using electrospinning method and compare their properties and structures with pure poly(l-lactide) (PLLA) fibers. The stereocomplexed fibers were electrospun from a blend solution of high molecular weight PLLA and poly(d-lactide) (1:1 ratio). The morphology of the obtained electrospun fibers was examined by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Differential scanning calorimetry was applied to study their thermal properties and crystallinity. Fourier transform infrared spectroscopy (FTIR) test was conducted on the samples to characterize their chemical properties. The SEM and AFM images indicated that smooth uniform fibers with a cylindrical structure were produced. Besides, the FTIR results and thermal properties confirmed that only stereocomplex crystallites formed in the resulting fibers via the electrospinning method.

Sign in / Sign up

Export Citation Format

Share Document