Performances and structure changes of neat PPS fiber and nano Ti-SiO2-modified PPS fiber after over-temperature oxidation

2017 ◽  
Vol 30 (3) ◽  
pp. 328-338 ◽  
Author(s):  
Dandan Lian ◽  
Ruiping Zhang ◽  
Jianjun Lu ◽  
Jinming Dai
Keyword(s):  
Photoelectron Spectroscopy ◽  
Crystalline Form ◽  
Supramolecular Structures ◽  
Polyphenylene Sulfide ◽  
Cross Linking ◽  
Scanning Calorimetry ◽  
Temperature Oxidation ◽  
Xps Spectra ◽  
X Ray ◽  
Structure Changes

Neat polyphenylene sulfide (PPS) fiber and nano titanium-silicon dioxide-modified PPS fibers (A-PPS) were submitted to an over-temperature in air environment at 200, 220, and 240°C for 24, 192, and 360 h, respectively. Molecular and supramolecular structures were characterized by differential scanning calorimetry, X-ray diffraction, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy (XPS). The outside color of the PPS fibers turned yellow and the mechanical properties were reduced after over-temperature, but the performances of the A-PPS fibers were better than that of the neat PPS fibers. The analyses of the molecular and supramolecular structures showed that the temperatures of 200 and 220°C could not change the crystalline form but could increase the crystallinity of the PPS fibers. The crystallization temperature high-shifted and the crystallization FWHM increased after over-temperature. More significant changes at 240°C could be observed such as breaking of the macromolecular chains, mutual cross-linking, and increase of the melting enthalpy to a higher value than the complete crystallization enthalpy of PPS. Cross-linking between the benzene rings and oxidation of the S atoms did not change the PPS crystalline form but decreased the lattice constant. XPS spectra showed that the cross-linking and oxidation of the S atoms of the PPS fibers mainly came from the breaking of the C–S–C bonds, while the break ratio of the C–S–C bonds was relatively smaller in the case of the A-PPS fibers.

Preparation and Characterization of Ni2+-Montmorillonite/Polyvinyl Alcohol Water-Soluble Nanocomposite Film

2005 ◽  
Vol 13 (8) ◽  
pp. 839-846 ◽  
Author(s):  
Li-Ping Wang ◽  
Yun-Pu Wang ◽  
Fa-Ai Zhang
Keyword(s):  
Polyvinyl Alcohol ◽  
Photoelectron Spectroscopy ◽  
Thermal Characteristics ◽  
Water Soluble ◽  
Scanning Calorimetry ◽  
Xps Spectra ◽  
X Ray ◽  
Alcohol Water ◽  
Ft Ir ◽  
Silicate Layers

A new type of nano-composite film was prepared from polyvinyl alcohol, Ni2+-montmorillonite (Ni2+-MMT), defoamer, a levelling agent and a plasticizer. Its thermal characteristics were studied by Differential Scanning Calorimetry (DSC). The intermolecular interactions were measured by Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS), and the tensile strength (TS) and elongation at break (%E) were measured. The microstructures were studied by X-ray diffraction (XRD) and atomic force microscopy (AFM). FT-IR and XPS spectra indicated that cross-linking has taken place between PVA and Ni2+-MMT. XRD and AFM indicate that the PVA molecules had inserted themselves into the silicate layers of MMT, exfoliating them and dispersing them randomly into the PVA matrix. Compared to pure PVA film, the TS of the films was increased and %E decreased when the Ni2+-Montmorillonite was added and the dissolution temperature of the film was also reduced.

scholarly journals Preparation of LiFePO4/C Cathode Materials via a Green Synthesis Route for Lithium-Ion Battery Applications

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2251 ◽  
Author(s):  
Rongyue Liu ◽  
Jianjun Chen ◽  
Zhiwen Li ◽  
Qing Ding ◽  
Xiaoshuai An ◽  
...  
Keyword(s):  
Cathode Materials ◽  
Photoelectron Spectroscopy ◽  
Raw Materials ◽  
Lithium Ion ◽  
Lithium Carbonate ◽  
Electrochemical Performances ◽  
Scanning Calorimetry ◽  
Xps Spectra ◽  
X Ray ◽  
Exhaust Purification

In this work, LiFePO4/C composite were synthesized via a green route by using Iron (III) oxide (Fe2O3) nanoparticles, Lithium carbonate (Li2CO3), glucose powder and phosphoric acid (H3PO4) solution as raw materials. The reaction principles for the synthesis of LiFePO4/C composite were analyzed, suggesting that almost no wastewater and air polluted gases are discharged into the environment. The morphological, structural and compositional properties of the LiFePO4/C composite were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), Raman and X-ray photoelectron spectroscopy (XPS) spectra coupled with thermogravimetry/Differential scanning calorimetry (TG/DSC) thermal analysis in detail. Lithium-ion batteries using such LiFePO4/C composite as cathode materials, where the loading level is 2.2 mg/cm2, exhibited excellent electrochemical performances, with a discharge capability of 161 mA h/g at 0.1 C, 119 mA h/g at 10 C and 93 mA h/g at 20 C, and a cycling stability with 98.0% capacity retention at 1 C after 100 cycles and 95.1% at 5 C after 200 cycles. These results provide a valuable approach to reduce the manufacturing costs of LiFePO4/C cathode materials due to the reduced process for the polluted exhaust purification and wastewater treatment.

scholarly journals Optical, XPS and XRD Studies of Semiconducting Copper Sulfide Layers on a Polyamide Film

2009 ◽  
Vol 2009 ◽  
pp. 1-8 ◽  
Author(s):  
Valentina Krylova ◽  
Mindaugas Andrulevičius
Keyword(s):  
Photoelectron Spectroscopy ◽  
Copper Sulfide ◽  
Diffusion Method ◽  
X Ray Diffraction ◽  
Xps Spectra ◽  
X Ray ◽  
Xrd Studies ◽  
Polyamide Film ◽  
Indirect Band Gap ◽  
Xrd Method

Copper sulfide layers were formed on polyamide PA 6 surface using the sorption-diffusion method. Polymer samples were immersed for 4 and 5 h in 0.15 mol⋅  solutions and acidified with HCl (0.1 mol⋅) at . After washing and drying, the samples were treated with Cu(I) salt solution. The samples were studied by UV/VIS, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) methods. All methods confirmed that on the surface of the polyamide film a layer of copper sulfide was formed. The copper sulfide layers are indirect band-gap semiconductors. The values of are 1.25 and 1.3 eV for 4 h and 5 h sulfured PA 6 respectively. Copper XPS spectra analyses showed Cu(I) bonds only in deeper layers of the formed film, while in sulfur XPS S 2p spectra dominating sulfide bonds were found after cleaning the surface with ions. It has been established by the XRD method that, beside , the layer contains as well. For PA 6 initially sulfured 4 h, grain size forchalcocite, , was  nm and fordjurleite, , it was 54.17 nm. The sheet resistance of the obtained layer varies from 6300 to 102 .

scholarly journals pH-controlled synthesis of sustainable lauric acid/SiO2 phase change material for scalable thermal energy storage

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shafiq Ishak ◽  
Soumen Mandal ◽  
Han-Seung Lee ◽  
Jitendra Kumar Singh
Keyword(s):  
Electron Microscopy ◽  
Phase Change ◽  
Lauric Acid ◽  
Photoelectron Spectroscopy ◽  
Phase Change Materials ◽  
Precursor Solution ◽  
Thermal Reliability ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Heating And Cooling

AbstractLauric acid (LA) has been recommended as economic, eco-friendly, and commercially viable materials to be used as phase change materials (PCMs). Nevertheless, there is lack of optimized parameters to produce microencapsulated PCMs with good performance. In this study, different amounts of LA have been chosen as core materials while tetraethyl orthosilicate (TEOS) as the precursor solution to form silicon dioxide (SiO2) shell. The pH of precursor solution was kept at 2.5 for all composition of microencapsulated LA. The synthesized microencapsulated LA/SiO2 has been characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), X-Ray photoelectron spectroscopy (XPS), Scanning electron microscopy (SEM), and Transmission electron microscopy (TEM). The SEM and TEM confirm the microencapsulation of LA with SiO2. Thermogravimetric analysis (TGA) revealed better thermal stability of microencapsulated LA/SiO2 compared to pure LA. PCM with 50% LA i.e. LAPC-6 exhibited the highest encapsulation efficiency (96.50%) and encapsulation ratio (96.15%) through Differential scanning calorimetry (DSC) as well as good thermal reliability even after 30th cycle of heating and cooling process.

scholarly journals An estimation on the mechanical stabilities of SAMs by low energy Ar+ cluster ion collision

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Y. Tong ◽  
G. R. Berdiyorov ◽  
A. Sinopoli ◽  
M. E. Madjet ◽  
V. A. Esaulov ◽  
...  
Keyword(s):  
Electron Irradiation ◽  
Photoelectron Spectroscopy ◽  
Density Functional ◽  
Crystal Surface ◽  
Depth Profiling ◽  
Low Energy ◽  
Cross Linking ◽  
Xps Spectra ◽  
Self Assembled ◽  
The Stability

AbstractThe stability of the molecular self-assembled monolayers (SAMs) is of vital importance to the performance of the molecular electronics and their integration to the future electronics devices. Here we study the effect of electron irradiation-induced cross-linking on the stability of self-assembled monolayer of aromatic 5,5′-bis(mercaptomethyl)-2,2′-bipyridine [BPD; HS-CH2-(C5H3N)2-CH2-SH] on Au (111) single crystal surface. As a refence, we also study the properties of SAMs of electron saturated 1-dodecanethiol [C12; CH3-(CH2)11-SH] molecules. The stability of the considered SAMs before and after electron-irradiation is studied using low energy Ar+ cluster depth profiling monitored by recording the X-ray photoelectron spectroscopy (XPS) core level spectra and the UV-photoelectron spectroscopy (UPS) in the valance band range. The results indicate a stronger mechanical stability of BPD SAMs than the C12 SAMs. The stability of BPD SAMs enhances further after electron irradiation due to intermolecular cross-linking, whereas the electron irradiation results in deterioration of C12 molecules due to the saturated nature of the molecules. The depth profiling time of the cross-linked BPD SAM is more than 4 and 8 times longer than the profiling time obtained for pristine and BPD and C12 SAMs, respectively. The UPS results are supported by density functional theory calculations, which show qualitative agreement with the experiment and enable us to interpret the features in the XPS spectra during the etching process for structural characterization. The obtained results offer helpful options to estimate the structural stability of SAMs which is a key factor for the fabrication of molecular devices.

29Si NMR and XPS Investigation of the Structure of Silicon Oxycarbide Glasses Derived from Polysiloxane Precursors

1994 ◽  
Vol 346 ◽  
Author(s):  
R.J.P. Corriu ◽  
D. Leclercq ◽  
P.H. Mutin ◽  
A. Vioux
Keyword(s):  
Solid State ◽  
Photoelectron Spectroscopy ◽  
Solid State Nmr ◽  
Random Distribution ◽  
Silicon Oxycarbide ◽  
29Si Nmr ◽  
Xps Spectra ◽  
Excess Carbon ◽  
X Ray ◽  
Silicon Oxycarbide Glasses

ABSTRACTTwo silicon oxycarbide glasses with different compositions (O/Si ratio 1.2 and 1.8) were prepared by pyrolysis at moderate temperature (900 °C) of polysiloxane precursors. Their structure was investigated using quantitative 29Si solid-state NMR and X-ray photoelectron spectroscopy (XPS). The environment of the silicon atoms in the oxycarbide phase corresponded to a purely random distribution of Si-O and Si-C bonds depending on the O/Si ratio of the glass only and not on the structure of the precursors. At the light of the NMR results, the Si2p XPS spectra of the glasses may be interpreted using the contribution of the five possible SiOxC4-x tetrahedra. The Cls spectra of these glasses indicated the presence of oxycarbide carbon in CSi4 tetrahedra, similar to carbide carbon, and graphitic-like excess carbon.

High Temperature Oxidation Behavior of SUS310S Austenitic Stainless Steel

2014 ◽  
Vol 941-944 ◽  
pp. 212-215
Author(s):  
Tao Zheng ◽  
Jing Tao Han
Keyword(s):  
Photoelectron Spectroscopy ◽  
Oxidation Behavior ◽  
Layer Structure ◽  
Energy Dispersive Spectrometer ◽  
Austenitic Stainless Steels ◽  
Temperature Oxidation ◽  
X Ray ◽  
High Temperature Oxidation Behavior ◽  
High Oxidation Resistance ◽  
Ray Diffusion

The oxidation behavior of SUS310S austenitic stainless steels was studied in isothermal conditions at different temperatures between 800oC and 1100oC for 96h in air. The oxidation kinetics was analyzed, the surface and cross-section of the oxide scale grown by oxidation were characterized by using scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), X-ray diffusion (XRD) and X-ray photoelectron spectroscopy (XPS). The SUS310S steel has high oxidation resistance at 800oC and with the increase of the temperature, the parabolic rate constants is constantly increasing. Examination of the morphology and composition of oxide layers reveals a double-layer structure, The inner layer is mainly chromium oxide (Cr2O3) and is covered by an uneven thinness outer layer of manganese-chromium or iron-chromium spinel oxide.

scholarly journals FORMULATION AND EVALUATION OF DOXORUBICIN CONTAINING NANOGELS FOR DELIVERY TO CANCER CELLS

2018 ◽  
Vol 8 (5) ◽  
pp. 178-183
Author(s):  
Manish Kumar ◽  
Hemant K. Sharma
Keyword(s):  
Average Particle Size ◽  
Gellan Gum ◽  
Cross Linking ◽  
Average Particle ◽  
Scanning Calorimetry ◽  
Green Method ◽  
X Ray ◽  
Oppositely Charged ◽  
Chemical Cross Linking

The objective of this study is to prepare nanogels were prepared via charged gellan gum. It was prepared by in situ cross linking reaction between two oppositely charged materials by green method without use of chemical cross linking agents. The prepared nanogels were characterized by Dynamic light scattering, scanning electron microscopy, differential scanning calorimetry and X- Ray diffractometry. The prepared formulation had average particle size of 226 nm with polydispersity index of 0.3. The doxorubicin loaded nanogel demonstrated sustained release for 20 h. The prepared nanogels were hemocompatible and cyctocompatible as revealed by hemocompatibility and MTT assay respectively. All results confirmed that these nanogels can be used for cancer treatment. Keywords: Nanogel, Chitosan, Gellan gum, Doxorubicin, Cancer.

scholarly journals Following excited-state chemical shifts in molecular ultrafast x-ray photoelectron spectroscopy

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
D. Mayer ◽  
F. Lever ◽  
D. Picconi ◽  
J. Metje ◽  
S. Alisauskas ◽  
...  
Keyword(s):  
Excited State ◽  
Chemical Shift ◽  
Photoelectron Spectroscopy ◽  
Chemical Shifts ◽  
Excited Molecule ◽  
Charge Motion ◽  
Core Electron ◽  
Xps Spectra ◽  
X Ray ◽  
State Chemical

AbstractThe conversion of photon energy into other energetic forms in molecules is accompanied by charge moving on ultrafast timescales. We directly observe the charge motion at a specific site in an electronically excited molecule using time-resolved x-ray photoelectron spectroscopy (TR-XPS). We extend the concept of static chemical shift from conventional XPS by the excited-state chemical shift (ESCS), which is connected to the charge in the framework of a potential model. This allows us to invert TR-XPS spectra to the dynamic charge at a specific atom. We demonstrate the power of TR-XPS by using sulphur 2p-core-electron-emission probing to study the UV-excited dynamics of 2-thiouracil. The method allows us to discover that a major part of the population relaxes to the molecular ground state within 220–250 fs. In addition, a 250-fs oscillation, visible in the kinetic energy of the TR-XPS, reveals a coherent exchange of population among electronic states.

scholarly journals Cross-Linking With Diamine Monomers to Prepare Graphene Oxide Composite Membranes With Varying D-Spacing for Enhanced Desalination Properties

2021 ◽  
Vol 9 ◽  
Author(s):  
Hong Ju ◽  
Jinzhuo Duan ◽  
Haitong Lu ◽  
Weihui Xu
Keyword(s):  
Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Water Flux ◽  
Covalent Bond ◽  
Composite Membranes ◽  
Rejection Rate ◽  
High Water ◽  
Cross Linking ◽  
Separation Performance ◽  
X Ray

As a new type of membrane material, graphene oxide (GO) can easily form sub-nanometer interlayer channels, which can effectively screen salt ions. The composite membrane and structure with a high water flux and good ion rejection rate were compared by the cross-linking of GO with three different diamine monomers: ethylenediamine (EDA), urea (UR), and p-phenylenediamine (PPD). X-ray photoelectron spectroscopy (XPS) results showed that unmodified GO mainly comprises π-π interactions and hydrogen bonds, but after crosslinking with diamine, both GO and mixed cellulose (MCE) membranes are chemically bonded to the diamine. The GO-UR/MCE membrane achieved a water flux similar to the original GO membrane, while the water flux of GO-PPD/MCE and GO-EDA/MCE dropped. X-ray diffraction results demonstrated that the covalent bond between GO and diamine can effectively inhibit the extension of d-spacing during the transition between dry and wet states. The separation performance of the GO-UR/MCE membrane was the best. GO-PPD/MCE had the largest contact angle and the worst hydrophilicity, but its water flux was still greater than GO-EDA/MCE. This result indicated that the introduction of different functional groups during the diamine monomer cross-linking of GO caused some changes in the performance structure of the membrane.

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