scholarly journals Silk Powder from Cocoons and Woven Fabric as a Potential Bio-Modifier

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6919
Author(s):  
Anna Baranowska-Korczyc ◽  
Andrzej Hudecki ◽  
Irena Kamińska ◽  
Małgorzata Cieślak
Keyword(s):  
Temperature Characteristic ◽  
Woven Fabric ◽  
Biological Applications ◽  
Scanning Calorimetry ◽  
Powder Morphology ◽  
Cryogenic Milling ◽  
Before And After ◽  
Low Toxicity ◽  
Degumming Process ◽  
Β Sheet

Silk, as a protein fiber characterized by high biocompatibility, biodegradability, and low toxicity, is mainly used as textile structures for various purposes, including for biological applications. The key issue for unlimited silk applicability as a modifier is to prepare its relevant form to cover or introduce to other materials. This study presents silk powder fabrication from Bombyx mori cocoons and non-dyed silk woven fabric through cryogenic milling. The cocoons were milled before and after the degumming process to obtain powders from raw structures and pure fibroin. The powder morphology and composition were analyzed using scanning electron microscopy and energy dispersive spectroscopy. The influence of the milling on the silk structure was studied using infrared and Raman spectroscopies, indicating that silk powders retained dominant β-sheet structure. The powders were also analyzed by differential scanning calorimetry and thermogravimetric techniques. The thermal endothermic peak and onset temperature characteristic for silk decomposition shifted to the lower values for all powders, indicating less thermal stability. However, the process was found to be an efficient way to obtain silk powders. The new milled form of silk can allow its introduction into different matrices or form coatings without using any harsh solvents, enriching them with new features and make more biologically friendly.

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.

Detonation Consolidation of NiFe/SiO2 and Co/SiO2 nanocomposites

2002 ◽  
Vol 759 ◽  
Author(s):  
Xinqing Ma ◽  
Y. D. Zhang ◽  
S. Hui ◽  
Mingzhong Wu ◽  
Shihui Ge ◽  
...  
Keyword(s):  
Magnetic Particles ◽  
Oxygen Mixture ◽  
Full Density ◽  
Magnetic Studies ◽  
Powder Morphology ◽  
Hypersonic Propulsion ◽  
Operation Conditions ◽  
Before And After ◽  
Propulsion Force ◽  
Size And Morphology

ABSTRACTConsolidation of nanostructure magnetic particles is required not only for manufacturing bulk component, it is actually a fundamental requirement for obtaining novel magnetic properties from the material. Consolidation (assembly) of nanoparticles to full density without deteriorating their nanostructure (size and morphology) is a big challenge. Here we present the consolidation experiments of NiFe/SiO2 and Co/SiO2 nanocomposites via detonation consolidation. This approach is based on the explosive pressure created when an acetylene and oxygen mixture gas fires in a sample containing tube, the very high hypersonic propulsion force makes nanoparticles deposit onto the target. Depending on the powder morphology and operation conditions, the density of the consolidated sample can reach over 91% of the theoretical density of the bulk materials. X-ray diffraction experiments on the samples before and after consolidation indicate that the denotation consolidations can be optimized such that it does not cause any phase transition. However, a particle size increase was observed. Static magnetic studies carried out on the samples before and after detonation operation shows that the saturation magnetization does not. This indicates that the operation does not cause an oxidation of the nanopowders. These experiments show that detonation approach is a good candidate for consolidating magnetic nanoparticles.

scholarly journals Application of Natural Dyes and Sodium Alginate From Sargassum Sp. Sea weed In Coloring Bima Woven Fabric

2020 ◽  
Vol 36 (05) ◽  
pp. 964-967
Author(s):  
Agrippina Wiraningtyan ◽  
Ruslan Ruslan ◽  
Putri Ayu Mutmainnah ◽  
Magfirah Perkasa
Keyword(s):  
Surface Structure ◽  
Sodium Alginate ◽  
Morphological Analysis ◽  
Woven Fabrics ◽  
Natural Dyes ◽  
Woven Fabric ◽  
Dyeing Process ◽  
Wave Numbers ◽  
Absorption Pattern ◽  
Before And After

This study aims to extract dye and alginate from seaweed Sargassum sp. as a dye paste in the coloring of Bima woven fabric. The concentration of sodium alginate used was 0%; 1%; 3% and 5%. The results showed that the absorbance value of the dye extract from seaweed Sargassum sp at maximum λ = 203 nm obtained A = 3.899. The effect of variations in the concentration of sodium alginate in the dye paste was determined by comparing the FTIR absorption pattern of Bima woven fabrics. Based on the FTIR absorption pattern data, it was found that a mixture of dye and sodium alginate of 3% had a stronger intensity, namely the wave numbers 3448.72 cm-1 and 1635 cm-1; 2900.94 cm-1; 2337.72 cm-1; 1381.03 cm-1 and 1064.71 cm-1. The results of the morphological analysis showed significant differences in surface structure on Bima woven fabrics before and after the dyeing process.

scholarly journals Utilization of Near IR Absorbing Gold Nanocolloids by Green Synthesis

2018 ◽  
Vol 915 ◽  
pp. 213-219
Author(s):  
Beste Elveren ◽  
Ümit Hakan Yildiz ◽  
Ahu Arslan Yildiz
Keyword(s):  
Drug Delivery ◽  
Tissue Engineering ◽  
Gold Nanoparticles ◽  
Binding Kinetics ◽  
Biological Applications ◽  
Near Ir ◽  
Novel Synthesis ◽  
Low Toxicity ◽  
Biological Environment ◽  
Unique Surface

The rapid developments in nanoscience, and its applications on biomedical areas have a large impact on drug delivery, tissue engineering, sensing, and diagnosis. Gold is widely investigated nanomaterial for the last couple of decades, since it has unique surface properties and very low toxicity to biological environment. In this work, we present a novel synthesis of gold nanoparticles (GNPs) exhibiting both visible and near-IR absorbance without agglomeration. The surface of GNPs were analyzed by routine methods and the binding kinetics were investigated by Surface Plasmon Resonance (SPR) Spectroscopy. The unique optical properties of near-IR asorbing GNP colloids hold promise for biological applications.

Expandable polystyrene without any embedded blowing agent

2020 ◽  
pp. 0021955X2094497
Author(s):  
Habib Haji Avdi ◽  
Morteza Nasiri ◽  
Mohammad Javad Tehrani ◽  
Maryam Alizadeh Aghdam ◽  
Farhang Abbasi
Keyword(s):  
Suspension Polymerization ◽  
Expansion Ratio ◽  
Scanning Calorimetry ◽  
Blowing Agents ◽  
Blowing Agent ◽  
Rate Of Polymerization ◽  
Polystyrene Matrix ◽  
Expandable Polystyrene ◽  
Before And After

In this research, in-situ suspension polymerization of styrene in the presence of graphene, without any blowing agent, was investigated. Steam used in the expansion process of graphene-filled expandable polystyrene (GEPS). The dispersed graphene nano-sheets in the polystyrene matrix may absorb water in high temperatures, which evaporates by lowering the pressure and expansion precedes. The effects of graphene type and loading and steam temperature on the expansion ratio evaluated. Scanning electron microscopy (SEM) used to reveal the cross-section morphologies before and after expansion. The effect of graphene on the polymerization kinetics evaluated by differential scanning calorimetry (DSC). The results showed that by increasing the graphene loading, the rate of polymerization decreased, and the expansion ratio increased. The highest expansion ratio of about 4.8 was for particles containing 0.4% of graphene. Therefore, it was shown that by using graphene as a dispersed phase, polystyrene particles expanded without any organic blowing agents. Here, the idea of expandable polymers without any embedded blowing agent is introduced, which eliminates the release of volatile organic compounds and makes the process environmentally friendly.

scholarly journals Microstructure Evolution and Performance Improvement of Hypereutectic Al–Mg2Si Metallic Composite with Ca or Sb

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2714
Author(s):  
Min Zuo ◽  
Boda Ren ◽  
Zihan Xia ◽  
Wenwen Ma ◽  
Yidan Lv ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Nucleation Behavior ◽  
X Ray ◽  
Primary Mg2si ◽  
Before And After ◽  
And Performance ◽  
Hardness Values

In this article, the modification effects on Al–Mg2Si before and after heat treatment were investigated with Ca, Sb, and (Ca + Sb). In comparison with single Ca or Sb, the samples with composition modifiers (Ca + Sb) had the optimal microstructure. The sample with a molar ratio for Ca-to-Sb of 1:1 obtained relatively higher properties, for which the Brinell hardness values before and after heat treatment were remarkably increased by 31.74% and 28.93% in comparison with bare alloy. According to differential scanning calorimetry analysis (DSC), it was found that the nucleation behavior of the primary Mg2Si phase could be significantly improved by using chemical modifiers. Some white particles were found to be embedded in the center of Mg2Si phases, which were deduced to be Ca5Sb3 through X-ray diffraction (XRD) and field-emission scanning electron microscope (FESEM) analyses. Furthermore, Ca5Sb3 articles possess a rather low mismatch degree with Mg2Si particles based on Phase Transformation Crystallography Lab software (PTCLab) calculation, meaning that the efficient nucleation capability of Ca5Sb3 for Mg2Si particles could be estimated.

Nucleating effect of surface modified MWNTs on crystallization of MWNTs/PA6 composites

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Juan Li ◽  
Qun Gu ◽  
Xinyu Fan ◽  
Zhenghong Guo ◽  
Zhengping Fang
Keyword(s):  
Polyamide 6 ◽  
Surface Characteristic ◽  
Crystalline Form ◽  
Scanning Calorimetry ◽  
Amino Functionalization ◽  
Before And After ◽  
Multi Walled Carbon Nanotubes ◽  
Surface Modified ◽  
Walled Carbon Nanotubes ◽  
Nucleating Effect

AbstractThe surface characteristic of multi-walled carbon nanotubes (MWNTs) plays an important role in the crystallization of polyamide 6 (PA6). In this paper, 1,6-hexamethylenediamine(HMD) are grafted on MWNTs. The MWNTs before and after modification are used to fabricate PA6 composites through melt-blending. The nucleating effect of MWNTs with different surface characteristic is investigated by differential scanning calorimetry (DSC), polarized optical microscopy (POM) and Xray diffraction (XRD).The heterogeneous nucleating ability of MWNTs determined by the Dobreva method are higher for pristine than amine-functionalized MWNTs/PA6 composites with 1.0 wt% MWNTs. Addition of MWNTs induce more heterogeneous nucleation and retards the crystal growth of PA6. The presence of MWNTs facilitates the formation of α crystalline form, while amino-functionalization weakens this trend. MWNTs act as effective nucleation agents for PA6, resulting in the increased number and decreased size of spherulites. MWNTs facilitate the formation of α crystalline form of PA6. Amino-functionalization decreases the crystallization and nucleating effect of MWNTs on PA6

Chemical Exchange Reactions in Blends of the Biodegradable Polyester with poly(hydroxy ether of bisphenol-A)

2014 ◽  
Vol 953-954 ◽  
pp. 1246-1249 ◽  
Author(s):  
Chean Cheng Su ◽  
Chern Hwa Chen ◽  
Neng Lang Shih ◽  
Yin Shuo Li
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Differential Scanning Calorimetry ◽  
Bisphenol A ◽  
Chemical Exchange ◽  
Exchange Reactions ◽  
Scanning Calorimetry ◽  
Butylene Succinate ◽  
Butylene Terephthalate ◽  
Before And After ◽  
Hydroxy Ether

Compatibilization via transreactions in blends of poly (butylene succinate-co-butylene terephthalate) [P(BS-co-BT)] with poly (hydroxy ether of bisphenol-A) (phenoxy) were investigated. Analyses were based on characterization using differential scanning calorimetry (DSC) and solid-state nuclear magnetic resonance (NMR). They revealed that the P(BS-co-BT)/phenoxy blend had a phase morphology that could be homogenized only following annealing at high temperatures. As-blended P(BS-co-BT)/phenoxy (50/50 composition) exhibited immiscible phases with two distinct Tgs, but the initially phase separated blends finally merged to form a homogeneous phase with a single Tgupon heating and annealing for 60 min at 280 °C. Chemical exchange reactions upon heat-annealing were likely to have caused the phase homogenization in the P(BS-co-BT)/phenoxy blend. NMR was performed on blend samples before and after they were heated to 280 °C, but the similarity of bonds made obtaining straight results difficult. Results of this study demonstrate phase homogenization can be brought only upon heat-annealing in the P(BS-co-BT)/phenoxy blend.

Thermal Cycling Treatment and Structural Changes in Cu-Al-Ni Monocrystalline Alloys

2006 ◽  
Vol 514-516 ◽  
pp. 692-696 ◽  
Author(s):  
Rui Jorge C. Silva ◽  
L.A. Matlakhova ◽  
E.C. Pereira ◽  
A.N. Matlakhov ◽  
Sérgio Neves Monteiro ◽  
...  
Keyword(s):  
Thermal Cycling ◽  
Structural Changes ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Critical Range ◽  
Cycling Treatment ◽  
Ni Alloy ◽  
Before And After ◽  
Number Of Cycles

In the present work a monocrystalline Cu-13.5Al-4Ni (wt.%) alloy with shape memory effect (SME) submitted to thermal cycling inside the critical range was investigated in terms of number of cycles and resulting structural changes. Attention was paid to the structural changes associated with reversible β1↔γ’1 martensite transformation. The monocrystalline Cu-Al-Ni alloy was produced in Russia, according to a specific technology. The structural characteristic of the alloys was studied through optical microscopy and X-ray diffraction methods using Cu-Kα radiation. Differential scanning calorimetry permitted the determination of the temperature range as well as a thermal effect due to the β1↔γ’1 martensitic reversible transformations, before and after 100, 200 and 300 thermal cycles.

Characteristics of Porous YAG Powders Fabricated by PVA Polymer Solution Technique

2007 ◽  
Vol 534-536 ◽  
pp. 21-24 ◽  
Author(s):  
Sang Jin Lee ◽  
P.W. Shin ◽  
J.W. Kim ◽  
S.Y. Chun
Keyword(s):  
Polymer Solution ◽  
Crystallization Behavior ◽  
Milling Process ◽  
Solution Technique ◽  
Scanning Calorimetry ◽  
Powder Morphology ◽  
X Ray ◽  
Electrophoretic Light Scattering ◽  
Micron Size ◽  
Primary Particles

Pure and stable YAG (Y3Al5O12) powders were synthesized by a PVA (polyvinyl alcohol) polymer solution technique. PVA was used as an organic carrier for the precursor ceramic gel. The PVA affected crystallization behavior, powder morphology, specific surface area and crystalline size of the synthesized powders. The precursor gels were crystallized to YAG at relatively a low temperature of 900 °C. The synthesized powders, which have nano-sized primary particles, were soft and porous, and the porous powders were ground to sub-micron size by a simple ball milling process. The ball-milled powders were densified to 94% relative density at 1500 °C for 1h. In this study, the characteristics of the synthesized YAG powders were examined by using X-ray diffractometer, simultaneous differential scanning calorimetry and electrophoretic light scattering spectrophotometer. And the morphologies of the powders and the densified samples were observed by scanning electron microscopy.

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