scholarly journals Effect of Microwave Irradiation on the Physical Properties and Structures of Cotton Fabric

2018 ◽  
Vol 13 (2) ◽  
pp. 155892501801300
Author(s):  
Zhao Xue
Keyword(s):  
Microwave Irradiation ◽  
Physical Properties ◽  
Cotton Fabric ◽  
Chemical Structure ◽  
Irradiation Time ◽  
Morphological Structure ◽  
Microwave Treatment ◽  
Radio Waves ◽  
X Ray Diffraction ◽  
Scanning Calorimetry

Microwaves are high frequency radio waves which are capable of penetrating many materials and causing heat to be generated in the process. To investigate the effect of microwave irradiation on the physical properties, chemical structure, surface morphological structure and fine structure of cotton fabric, cotton fabric was treated with microwave irradiation under variety of conditions in terms of the power and the time of microwave treatment. The breaking strength, breaking elongation, and whiteness of the treated cotton fabric in wet state were investigated. The structures of the untreated and treated cotton were investigated with Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The results show that the physical properties of the treated cotton fabrics were changed with microwave irradiation time and power. The chemical structure and the surface morphological structure did not significantly change. Crystallinity of the treated cotton was changed.

scholarly journals Effect of Microwave Irradiation on the Physical Properties and Structure of Silk Fibre

2018 ◽  
Vol 26 (4(130)) ◽  
pp. 111-115
Author(s):  
Xue Zhao
Keyword(s):  
Microwave Irradiation ◽  
Physical Properties ◽  
Irradiation Time ◽  
Morphological Structure ◽  
Microwave Treatment ◽  
Decomposition Temperature ◽  
Silk Fibre ◽  
Silk Fabric ◽  
Scanning Calorimetry ◽  
Chemical Surface

Microwaves are high frequency radio waves which are capable of penetrating many materials and causing heat to be generated in the process. To investigate the effect of microwave irradiation on the physical properties as well as the chemical , surface morphological and fine structure of silk fabric, silk fabric was treated with microwave irradiation under a variety of conditions in terms of the power and time of microwave treatment. The breaking strength, elongation at break, and whiteness of the treated silk fabric in a wet state were investigated. The structures of the untreated and treated silk were investigated with Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The results show that the physical properties of the treated silk fabrics were changed with the microwave irradiation time. The chemical and surface morphological structure as well as the decomposition temperature and crystallinity of the treated silk were changed.

scholarly journals Enhancement of solubility and dissolution rate of poorly water soluble raloxifene using microwave induced fusion method

2013 ◽  
Vol 49 (3) ◽  
pp. 571-578 ◽  
Author(s):  
Payal Hasmukhlal Patil ◽  
Veena Sailendra Belgamwar ◽  
Pratibha Ramratan Patil ◽  
Sanjay Javerilal Surana
Keyword(s):  
Dissolution Rate ◽  
Hydroxypropyl Methylcellulose ◽  
Microwave Treatment ◽  
Water Soluble ◽  
Fusion Method ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Wetting Properties ◽  
Poorly Soluble ◽  
Poorly Water Soluble

The objective of the present work was to enhance the solubility and dissolution rate of the drug raloxifene HCl (RLX), which is poorly soluble in water. The solubility of RLX was observed to increase with increasing concentration of hydroxypropyl methylcellulose (HPMC E5 LV). The optimized ratio for preparing a solid dispersion (SD) of RLX with HPMC E5 LV using the microwave-induced fusion method was 1:5 w/w. Microwave energy was used to prepare SDs. HPMC E5 LV was used as a hydrophilic carrier to enhance the solubility and dissolution rate of RLX. After microwave treatment, the drug and hydrophilic polymer are fused together, and the drug is converted from the crystalline form into an amorphous form. This was confirmed through scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and powder X-ray diffraction (PXRD) studies. These results suggested that the microwave method is a simple and efficient method of preparing SDs. The solubility and dissolution rate of the SDs were increased significantly compared with pure RLX due to the surfactant and wetting properties of HPMC E5 LV and the formation of molecular dispersions of the drug in HPMC E5 LV. It was concluded that the solubility and dissolution rate of RLX are increased significantly when an SD of the drug is prepared using the microwave-induced fusion method.

Thermotropic behavior of sodium cholesteryl carbonate

2009 ◽  
Vol 24 (1) ◽  
pp. 156-163 ◽  
Author(s):  
Rabkwan Chuealee ◽  
Timothy S. Wiedmann ◽  
Teerapol Srichana
Keyword(s):  
Phase Behavior ◽  
Chemical Structure ◽  
Liquid Crystalline ◽  
Polarized Light ◽  
Wave Number ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
X Ray Scattering ◽  
C Nmr

Sodium cholesteryl carbonate ester (SCC) was synthesized, and its phase behavior was studied. The chemical structure was assessed by solid-state infrared spectroscopy based on vibration analysis. The wave number at 1705 and 1276 cm−1 corresponds to a carbonyl carbonate and O–C–O stretching of SCC, respectively. Molecular structure of SCC was further investigated with 1H and 13C NMR spectroscopy. The chemical shift, for the carbonyl carbonate resonance appeared at 155.5 ppm. A molecular mass of SCC was at m/z of 452. Differential scanning calorimetry (DSC), video-enhanced microscopy (VEM) together with polarized light microscopy, and small-angle x-ray scattering (SAXS) were used to characterize the phase behavior as a function of temperature of SCC. Liquid crystalline phase was formed with SCC. Based on the thermal properties and x-ray diffraction, it appears that SCC forms a structure analogous to the type II monolayer structure observed with cholesterol esters.

scholarly journals Brazilian gutta-percha points. Part II: thermal properties

2007 ◽  
Vol 21 (1) ◽  
pp. 29-34 ◽  
Author(s):  
Cláudio Maniglia-Ferreira ◽  
Eduardo Diogo Gurgel-Filho ◽  
João Batista Araújo Silva Jr ◽  
Regina Célia Monteiro de Paula ◽  
Judith Pessoa Andrade Feitosa ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Thermal Properties ◽  
Physical Properties ◽  
Ambient Temperature ◽  
Amorphous Phase ◽  
Thermal Behaviour ◽  
Chemical Structure ◽  
Scanning Calorimetry ◽  
Gutta Percha ◽  
Thermal Manipulation

This study was undertaken to explore the effect of heating on gutta-percha, analyzing the occurrence of endothermic peaks corresponding to the transformation that occurs in the crystalline structure of the polymer during thermal manipulation. This study also seeked to determine the temperature at which these peaks occur, causing a transformation from the beta- to the alpha-form, and from the alpha- to the amorphous phase. Eight nonstandardized gutta-percha points commercially available in Brazil (Konne, Tanari, Endopoint, Odous, Dentsply 0.04, Dentsply 0.06, Dentsply TP, Dentsply FM) and pure gutta-percha (control) were analysed using differential scanning calorimetry (DSC) and thermogravimetry analysis (TGA). The transition temperatures were determined and analysed. With the exception of Dentsply 0.04 and Dentsply 0.06, the majority of the products showed thermal behaviour typical of beta-gutta-percha, with two endothermic peaks, exhibiting two crystalline transformations upon heating from ambient temperature to 130°. Upon cooling and reheating, few samples presented two endothermic peaks. It was concluded that heating dental gutta-percha to 130°C causes changes to its chemical structure which permanently alter its physical properties.

Investigating the carbon materials’ microwave absorption and its effects on the mechanical and physical properties of carbon fiber and carbon black/ polypropylene composites

2016 ◽  
Vol 51 (16) ◽  
pp. 2263-2276 ◽  
Author(s):  
Jafar Rezania ◽  
Hamid Rahimi
Keyword(s):  
Microwave Irradiation ◽  
Physical Properties ◽  
Carbon Materials ◽  
Loss Modulus ◽  
Polymeric Materials ◽  
Microwave Treatment ◽  
Structural Defects ◽  
Polypropylene Composites ◽  
Dynamic Mechanical ◽  
Mechanical And Physical Properties

Carbon compounds have high dielectric losses, which means that these materials are heated efficiently by microwave irradiation. Carbon materials can be used as microwave absorbers in polymeric materials that are transparent to microwave irradiation. In this paper, carbon-reinforced polypropylene composites were exposed to microwave irradiation and then their dynamic mechanical thermal properties, electromagnetic shielding, and surface morphology were investigated. The test results showed that mechanical and physical properties of carbon–polypropylene composites improved following microwave exposure. The dynamic mechanical thermal analysis results showed that their storage and loss modulus were improved following microwave treatment. It is postulated that microwave irradiation heats carbon materials, which is likely to melt neighboring matrix thus improving interfacial adhesion and structural defects.

scholarly journals Influence of the Duration of Microwave Irradiation of Scots Pine (Pinus sylvestris L.) Cones on the Quality of Harvested Seeds

Forests ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 1108
Author(s):  
Monika Aniszewska ◽  
Arkadiusz Gendek ◽  
Ewa Tulska ◽  
Paulina Pęska ◽  
Tadeusz Moskalik
Keyword(s):  
Microwave Irradiation ◽  
Irradiation Time ◽  
Initial Moisture Content ◽  
Outer Part ◽  
Microwave Treatment ◽  
Quality Class ◽  
Short Period ◽  
Seed Extraction ◽  
Pine Cones

To improve the process of seed extraction, new solutions have been investigated in an attempt to develop guidelines for the construction of small seed extraction equipment. One of the solutions proposed in this field is the use of electromagnetic radiation in the first stage of hulling cones, reducing their initial moisture content, which will result in quicker scale opening. It is proposed that cones should be irradiated for a relatively short period in the first stage. This operation will allow a quicker loss of moisture from the cones that are still closed, which will result in a more intensive opening of cone scales and will also positively affect the exposure of seeds for the next phase of hulling. The aim of the study was to evaluate the effect of microwave irradiation of pine cones on the quality of the seeds obtained. Cones were exposed to microwaves produced by an 800 W generator. The research was performed in several modes, in which the variable parameters were the duration of microwave irradiation, arrangement of cones with the apex pointed towards either the inner or outer part of the turntable, and the number of cones. The temperature distribution on the surface of and inside the cones was determined using the THERM v2 (Vigo System SA, Ożarów Mazowiecki, Poland) thermal image processing software. We also assessed the energy (vitality) and germinability (quality class) of seeds that were not exposed and those after microwave treatment. The results of the research allowed us to state that, with the assumed parameters of the process, it is possible to obtain second quality class seeds after exposure to microwaves for 5 s. This result was comparable to the quality of seeds obtained without the use of microwaves. When the irradiation time was increased above 5 s, the vitality of seeds decreased and their quality was not satisfactory.

Graft Copolymerization of Chitosan with L-Lactide under Microwave Irradiation

2015 ◽  
Vol 778 ◽  
pp. 120-123
Author(s):  
Ye Tian ◽  
Qing Hui Zeng ◽  
Ya Qing Ren ◽  
Xiao Fan He
Keyword(s):  
Thermal Stability ◽  
Low Temperature ◽  
Microwave Irradiation ◽  
Physical Properties ◽  
Ring Opening ◽  
Chemical Structure ◽  
Graft Copolymerization ◽  
Short Time

Poly (L-lactide) was grafted onto chitosan by ring-opening copolymerization under microwave irradiation in the presence of tin octoate (Sn (Oct)2) as catalyst. The chemical structure and physical properties of the copolymers with different feeding ratios were discussed by FTIR, DTG and X-RD, taking pure chitosan as reference. The results showed that the application of microwave irradiation in the reaction could achieve the copolymer with high grafting percentage in a short time and low temperature. The thermal stability and crystallinity were decreased with the feeding ratio increasing, attributing to the increasing of grafting percentage.

Effects of Pea Protein on the Properties of Potato Starch-Based 3D Printing Materials

2018 ◽  
Vol 14 (3) ◽  
Author(s):  
Feng Chuanxing ◽  
Wang Qi ◽  
Li Hui ◽  
Zhou Quancheng ◽  
Meng Wang
Keyword(s):  
3D Printing ◽  
Chemical Structure ◽  
Potato Starch ◽  
Textural Properties ◽  
Theoretical Research ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Pea Protein ◽  
X Ray ◽  
Printing Quality

AbstractSince materials are the substantial foundation for 3D printing, the lack of theoretical research on 3D printing food materials restricts the development of 3D printing in food field. Based on the principle of 3D starch gelatinization printing, this study revealed the effects of pea protein on the printability of potato starch-based 3D printing materials in granular structure, crystalline structure, chemical structure, textural properties, and thermal properties, through scanning electron microscope, X-ray diffraction, Fourier-transformed infrared, differential scanning calorimetry, and textural method, and developed new food materials for 3D printing. The study indicated the structural properties and physicochemical properties changed regularly with the increase in the content of pea protein, when the content of pea protein was 1%, the printing quality was best. The study provides a new theory for the application of 3D printing in food production and technical support for actual production.

scholarly journals Effects of Hydrothermal and Microwave Dual Treatment and Zein on the Enzymolysis of High Amylose Corn Starch

Gels ◽  
2022 ◽  
Vol 8 (1) ◽  
pp. 29
Author(s):  
Jie Liu ◽  
Qiuye Yang ◽  
Tiantian Yuan ◽  
Yawei Liu ◽  
Guihong Fang
Keyword(s):  
Moisture Content ◽  
Corn Starch ◽  
Average Particle Size ◽  
Microwave Treatment ◽  
Decomposition Temperature ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
High Amylose

Resistant starch (RS) type 2-high-amylose corn starch (HACS) was subjected to simultaneous hydrothermal (25% moisture content, 90 °C for 12 h) and microwave (35% moisture content, 40 W/g microwaving for 4 min) treatment and zein (at a zein to treated starch ratio of 1:5, 50 °C for 1 h) to improve its resistance to enzymolysis. Scanning electron microscopy (SEM) highlighted the aggregation and adhesion of the composite. The average particle size of the composite (27.65 μm) was exceeded that of both the HACS (12.52 μm) and the hydrothermal and microwave treated HACS (hydro-micro-HACS) (12.68 μm). The X-ray diffraction results revealed that the hydro-micro-HACS and composite remained B-type, while their crystallinity significantly decreased to 16.98% and 12.11%, respectively. The viscosity of the hydro-micro-HACS and composite at 50 °C was 25.41% and 35.36% lower than that of HACS. The differential scanning calorimetry (DSC) results demonstrated that the composite displayed a new endothermic peak at 95.79 °C, while the weight loss rate and decomposition temperature were 7.61% and 2.39% lower than HACS, respectively. The RS content in HACS, the hydro-micro-HACS, and composite was 47.12%, 57.28%, and 62.74%, respectively. In conclusion, hydrothermal and microwave treatment combined with zein provide an efficient physical strategy to enhance the RS type 2-HACS.

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