Effects of a Clean Subcritical Degreasing System on Wool Fibers

2021 ◽  
Vol 116 (5) ◽  
Author(s):  
Qiao Xia ◽  
Yinxuan Wang ◽  
Meina Zhang ◽  
Zongcai Zhang ◽  
Hong Dai
Keyword(s):  
Disulfide Bonds ◽  
Structural Changes ◽  
Depth Of Field ◽  
Diffraction Experiment ◽  
X Ray ◽  
Scale Layer ◽  
Wool Fibers ◽  
Α Helix ◽  
Thermal Stability Of ◽  
Scanning Electron

It makes sense to use environmentally friendly methods of degreasing in fur-making process. In this study, subcritical n-pentane was used to degrease wool fibers. Thermogravimetric analysis (TGA) was used to observe and analyze the properties of the subcritical n-pentane degreased wool fibers. The results showed that the thermal stability of the fibers increased. Fourier Transform Infrared (FTIR) spectroscopy was used to analyze the structural changes of macromolecular chains in wool fibers. It was found that when the pressure was higher than 0.4 MPa, the wool fibers underwent a conformational change with the α-helix changing to β-folding. If the pressure was as high as 0.6 MPa, the disulfide bonds in the wool fibers scale layer appeared to break. X-ray powder diffraction experiment was used to study changes in wool fiber aggregation morphology. It was demonstrated that the crystalline zone of wool fibers changed and the fibers index grew, from 22.89% to 30.19%. Field emission scanning electron microscopy and ultra-depth of field microscopy was used to analyze changes in the surface morphology of wool fibers. The results suggested that after the treatment, the wool fibers were not damaged and the impurities on the wool surface were reduced.

Sem/X-Ray Applications to the Forensic Science Field

1976 ◽  
Vol 34 ◽  
pp. 390-391
Author(s):  
K. Culbreth
Keyword(s):  
Forensic Science ◽  
Depth Of Field ◽  
Surface Phenomena ◽  
Criminal Cases ◽  
Forensic Evidence ◽  
Science Field ◽  
X Ray ◽  
Hit And Run ◽  
Evaluation Of Evidence ◽  
Scanning Electron

The introduction of scanning electron microscopy and energy dispersive x-ray analysis to forensic science has provided additional methods by which investigative evidence can be analyzed. The importance of evidence from the scene of a crime or from the personal belongings of a victim and suspect has resulted in the development and evaluation of SEM/x-ray analysis applications to various types of forensic evidence. The intent of this paper is to describe some of these applications and to relate their importance to the investigation of criminal cases.The depth of field and high resolution of the SEM are an asset to the evaluation of evidence with respect to surface phenomena and physical matches (1). Fig. 1 shows a Phillips screw which has been reconstructed after the head and shank were separated during a hit-and-run accident.

scholarly journals Improvement of the thermal stability of dendritic silver-coated copper microparticles by surface modification based on molecular self-assembly

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Tae Hyeong Kim ◽  
Hyeji Kim ◽  
Hyo Jun Jang ◽  
Nara Lee ◽  
Kwang Hyun Nam ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Photoelectron Spectroscopy ◽  
Self Assembly ◽  
Electrically Conductive ◽  
X Ray ◽  
Alkyl Chains ◽  
Conductive Film ◽  
Initial Resistance ◽  
Thermal Stability Of ◽  
Scanning Electron

AbstractIn the study reported herein, silver-coated copper (Ag/Cu) powder was modified with alkanethiols featuring alkyl chains of different lengths, namely butyl, octyl, and dodecyl, to improve its thermal stability. The modification of the Ag/Cu powders with adsorbed alkanethiols was confirmed by scanning electron microscopy with energy dispersive spectroscopy, X-ray photoelectron spectroscopy, and thermogravimetric analysis. Each powder was combined with an epoxy resin to prepare an electrically conductive film. The results confirmed that the thermal stability of the films containing alkanethiol-modified Ag/Cu powders is superior to that of the film containing untreated Ag/Cu powder. The longer the alkyl group in the alkanethiol-modified Ag/Cu powder, the higher the initial resistance of the corresponding electrically conductive film and the lower the increase in resistance induced by heat treatment.

scholarly journals Obtaining human hair keratin-based films and their characteristics

2021 ◽  
Vol 15 (1) ◽  
pp. 27-36
Author(s):  
V. V. Mykhaliuk ◽  
◽  
V. V. Havryliak ◽  
Keyword(s):  
Molecular Weight ◽  
Disulfide Bonds ◽  
Protein Concentration ◽  
Sodium Dodecyl ◽  
Protein Composition ◽  
Surface Characteristics ◽  
Film Structure ◽  
X Ray ◽  
Wide Range ◽  
Scanning Electron

Background. Keratins are natural biopolymers with a wide range of applications in the field of biotechnology. Materials and Methods. Extraction of keratins was performed by a modified Nakamura method using 250 mM DTT. The protein concentration in the supernatant was determined by Bradford method. The protein composition was studied by their electro­phoretic separation in a polyacrylamide gel in the presence of sodium dodecyl sulfate. The films were made by casting. The surface characteristics of the films were determined using a scanning electron microscope REMMA-102. The elemental composition of the films was determined using an X-ray microanalyzer. Results. The protein concentration in the supernatant was 3.75 mg/mL. After using dithiothreitol in the extraction mixture, we obtained proteins of intermediate filaments with a molecular weight of 40–60 kDa and a low Sulfur content. In the low molecular weight region, we obtained keratin-associated proteins with a molecular weight of 10–30 kDa and a high content of Sulfur. These proteins belong to fibrillar proteins, which can be used as a matrix for the creation of new keratin-containing biocomposites with a wide range of applications in reparative medicine and tissue engineering. Based on the obtained keratin extract, polymer films with and without the addition of glycerol were made. Scanning electron microscopy revealed that glycerol provided the film structure with homogeneity and plasticity due to the accumulation of moisture after the fixation by water vapor. The X-ray microanalysis of films revealed such elements as Sodium, Silicon, Sulfur, Potassium. Among the detected elements, Sulfur has the largest share that is due to the large number of disulfide bonds in the keratin molecule. Conclusions. The polymer keratin films with the addition of glycerol demonstrated better mechanical properties and can be used in biomedicine.

scholarly journals Structural and thermoelectric properties of the Pr2Zr2O7 compound

2019 ◽  
pp. 4-9
Author(s):  
Adolfo Quiroz-Rodríguez ◽  
Cesia Guarneros-Aguilar ◽  
Ricardo Agustin-Serrano
Keyword(s):  
Electron Microscopy ◽  
Thermal Conductivity ◽  
Thermoelectric Properties ◽  
Crystal Size ◽  
Ambient Pressure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Increasing Temperature ◽  
Thermal Stability Of ◽  
Scanning Electron

In this research, it is presented a detailed study of the structural and thermoelectric properties of the pyrochlore zirconium Pr2Zr2O7 compound prepared by solid-state reaction (SSR) in air at ambient pressure. The synthesized sample was characterized using powder X-ray diffraction. The thermal stability of the thermoelectric compound (TE) Pr2Zr2O7 was tested by thermogravimetric analysis (TGA) and differential thermal analysis (DTA). Scanning electron microscopy shows that the crystal size varies between 0.69 and 2.81μm. Electrical conductivity (\sigma) of the sample calcined at 1400 °C presented values increase irregularly with the increasing temperature from 0.001 to 0.018 S cm-1 as expected in a semiconductor material. The thermal conductivity is lower than 0.44 - 775 W m-1 K-1 which is quite anomalous in comparison with the thermal conductivity of other oxides.

Carboxyl graphene reinforced melamine-based polyamide nanocomposites

2021 ◽  
pp. 089270572110514
Author(s):  
Himanshu V Madhad ◽  
Dilip V Vasava
Keyword(s):  
Electron Microscopy ◽  
Decomposition Temperature ◽  
Differential Scanning Calorimetric ◽  
X Ray Diffraction ◽  
One Pot ◽  
X Ray ◽  
Mild Conditions ◽  
Thermal Stability Of ◽  
Infrared Techniques ◽  
Scanning Electron

Over the years, various types of techniques have been used for the synthesis of nanocomposites. In this work, melamine-based polyamide (PA) was synthesized using a one-pot polycondensation method under mild conditions. carboxyl graphene (CG)/PA nanocomposites (CGMPA) were prepared by CG nanofiller loadings of 1, 3, and 5 wt.% via delamination/adsorption approach. The prepared CGMPA nanocomposites were characterized using different analyses, such as Fourier transform infrared techniques (FTIR), field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), differential scanning calorimetric (DSC), and thermogravimetric analysis (TGA). The effects of the CG on the thermal properties of the CGMPA nanocomposites were significant. The results showed that the melting temperature (Tm) of neat PA and CGMPA were increased from 378°C to 393°C suggested better dispersion of CG in PA matrix. The decomposition temperature of PA was increased from 451°C to 463°C in CGMPA nanocomposites indicates the better thermal stability of PA matrix by addition of CG.

scholarly journals Structural Changes in the Aluminum - Magnesium System Alloy

2020 ◽  
Vol 989 ◽  
pp. 577-582
Author(s):  
I.E. Illarionov ◽  
T.R. Gilmanshina ◽  
A.A. Kovaleva
Keyword(s):  
Mechanical Properties ◽  
Structural Changes ◽  
Single Phase ◽  
Secondary Phases ◽  
Micro Hardness ◽  
System Alloy ◽  
Quenching Temperature ◽  
Monitor Screen ◽  
X Ray ◽  
Scanning Electron

The purpose of this work is to study the structure and mechanical properties of an aluminum – magnesium system alloy after various types of heat treatment (quenching and ageing). The microstructure of an alloy has been studied by means of Zeiss OBSERVER.D1m microscope combined with a camera and image display on a monitor screen. Micro X-ray spectral analysis was performed by means of Carl Zeiss EVO 50 scanning electron microscope. The micro-hardness of the samples has been measured on prepared metallographic sections by means of DM8 micro-hardness meter. In the course of the process it has been found that quenching the Al-12,78% Mg alloy from temperatures of 430–440 ° C does not lead to the formation of a single-phase solid solution. Ageing at 100 ° C enables the formation of secondary phases. It was noted that with an increase in the quenching temperature, the micro-hardness increases slightly. An increase in the exposure time doesn’t influence greatly the micro-hardness of the alloy, while the structure remains practically unchanged.

Mechanics and hierarchical structure transformation mechanism of wool fibers

2020 ◽  
pp. 004051752094424
Author(s):  
Hongling Liu ◽  
Liang Zhao ◽  
Guosheng Zhang ◽  
Feng Pan ◽  
Weidong Yu
Keyword(s):  
Hierarchical Structure ◽  
Disulfide Bonds ◽  
Solution Concentration ◽  
Single Fiber ◽  
Cold Weather ◽  
Structure Transformation ◽  
Transformation Mechanism ◽  
External Threats ◽  
Wool Fibers ◽  
Α Helix

Various natural protein materials have hierarchical microscale and nanoscale structures that protect animals from suffering cold weather or external threats. Herein, we contribute an effective strategy for exploring the hierarchical structure transformation mechanism by stretching a single fiber and bundle fibers. Taking advantage of controllable stretching, the disulfide bonds and peptide chains were taken apart or reconstructed by the new crosslinking bonds inside the wool fiber. If the temperature, solution concentration and stretching velocity were appropriate, the strain was more than 230% and the microstructure transformation of a single fiber underwent α→ β transition, disulfide bond breakage and macromolecule slippage occurred during the tensile process. The transformation mechanism was modeled and experimentally tested in wool bundle fibers after setting, suggesting that the stretching led to the transformation from α helix to β-pleated sheet, the breakage of disulfide bonds and the slippage of microfibrils. The availability of wool fibers provides many opportunities for bio-friendly cellular substrates and biosensor devices.

scholarly journals Preparation and Properties of Ginger Essential Oil β-Cyclodextrin/Chitosan Inclusion Complexes

Coatings ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 305 ◽  
Author(s):  
Yan Zhang ◽  
Hui Zhang ◽  
Fang Wang ◽  
Li-Xia Wang
Keyword(s):  
Particle Size ◽  
Essential Oil ◽  
Spray Drying ◽  
Small Particle Size ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Ft Ir ◽  
Thermal Stability Of ◽  
Scanning Electron

The ginger essential oil/β-cyclodextrin (GEO/β-CD) composite, ginger essential oil/β-cyclodextrin/chitosan (GEO/β-CD/CTS) particles and ginger essential oil/β-cyclodextrin/chitosan (GEO/β-CD/CTS) microsphere were prepared with the methods of inclusion, ionic gelation and spray drying. Their properties were studied by using scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermo-gravimetry analysis (TGA), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). The results showed that the particle size of GEO/β-CD composite was smaller than that of β-CD and GEO/β-CD/CTS particles were loose and porous, while the microsphere obtained by spray drying had certain cohesiveness and small particle size. Besides, results also indicated that β-CD/CTS could modify properties and improve the thermal stability of GEO, which would improve its application value in food and medical industries.

Surface Modification of 1-Butyl-3-Methylimidazolium Chloride -Treated Lignocellulosic Materials

2020 ◽  
Vol 1010 ◽  
pp. 526-531
Author(s):  
Asanah Radhi ◽  
Abdullah Othman ◽  
Muhammad Afif Aziz ◽  
Nik Raihan Nik Yusoff
Keyword(s):  
Electron Microscopy ◽  
Surface Modification ◽  
Functional Group ◽  
Hydroxyl Groups ◽  
Lignocellulosic Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hexadecyl Trimethylammonium Bromide ◽  
Thermal Stability Of ◽  
Scanning Electron

Lignocellulosic materials are generally considered hydrophilic due to the high density of hydroxyl groups. The use of lignocellulosic materials in hydrophobic systems thus require surface modification. Therefore, in this study, cellulose (MCC) and sawdust (SD) have been pretreated with ionic liquid, 1-butyl-3-methylimidazolium chloride (BMIMCl) prior to surface modification with cationic surfactant, hexadecyl trimethylammonium bromide (CTAB). The effect of BMIMCl pretreatment prior to surface modification has been investigated. Crystallinity, functional group changes, morphology and thermal stability of the sawdust and cellulose upon BMIMCl pretreatment and surface modification have been studied using x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and thermogravimetric Analysis (TGA). XRD results showed that the structure of lignocellulosic materials became more amorphous upon pretreatment with BMIMCl. FTIR results indicated that the modification of lignocellulosic is more efficient in BMIMCl-pretreated samples. Percentage of decomposition is higher for the BMIMCl-pretreated and CTAB modified samples.

Characterization of PET-Silver Nanocomposite Filaments

2018 ◽  
Vol 930 ◽  
pp. 224-229
Author(s):  
Marcos Antônio Guerra ◽  
Jeferson Prado Swerts ◽  
Mei Abe Funcia ◽  
Neide Aparecida Mariano ◽  
Maria Gabriela Nogueira Campos
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Scanning Electron Microscopy ◽  
Silver Nanoparticles ◽  
Addition Method ◽  
X Ray ◽  
Silver Nanocomposite ◽  
Thermal Stability Of ◽  
Scanning Electron

Polyethylene terephthalate (PET) fiber is a very versatile fiber that can be produced with different properties, such as antimicrobial activity. This study aims to synthesize antimicrobial PET filaments incorporated with silver nanoparticles immobilized in silica (NPAg-Si) by bulk additive method. Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX) characterized the obtained filaments at concentrations (w/w) of 0.008%, 0.016%, 0.032%, 0.047% and 0.063% NPAg-Si, in order to identify the nanoparticles and analyze their dispersion in the polymeric matrix. Moreover, thermogravimetric analysis (TGA) was carry out to confirm the presence and concentration of the silver nanoparticles in the filaments as well as the thermal stability of the nanocomposites. The bulk addition method was efficient to produce PET-Silver filaments with silver nanoparticles homogeneously dispersed in the PET matrix.

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