Bromination reaction in C  C double bond determination by XPS

Povstugar, V. I.; Lyakhovich, A. M.; Shakov, A. A.

doi:10.1016/0368-2048(94)02159-7

Cited by 7 publications

(6 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Compared with GO-COOH, the C/F ratio for GO@HEMA increases almost 6 times, a strong indication that most of the carboxyl groups are esterified with HEMA and therefore unreactive towards TFE (transesterification reactions are unlikely to occur here). For the analysis of alkenyl surface groups, a gas-phase bromination reaction was used, as it is known that under these conditions bromine adds to double bonds in unsaturated carboxylic acid derivatives 22 . The appearance of bromine peaks in the survey scans of Br 2 -derivatized GO-COOH and GO@HEMA can be explained by intercalation of molecular Br 2 between the graphene sheets, presumably forming C n -Br 2 charge-transfer complexes 32 or by a reaction with surface carboxyl groups to form carboxyl bromides 33 .…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Hema-Functionalized Graphene Oxide: a Versatile Nanofiller for Poly(Propylene Fumarate)-Based Hybrid Materials

Vasile

Pandele

Andronescu

et al. 2019

Sci Rep

View full text Add to dashboard Cite

Poly(propylene fumarate) (PPF) is a linear unsaturated polyester which has been widely investigated for tissue engineering due to its good biocompatibility and biodegradability. In order to extend the range of possible applications and enhance its mechanical properties, current approaches consist in the incorporation of various fillers or obtaining blends with other polymers. In the current study we designed a reinforcing agent based on carboxylated graphene oxide (GO-COOH) grafted with 2-hydroxyethyl methacrylate (GO@HEMA) for poly(propylene fumarate)/poly(ethylene glycol) dimethacrylate (PPF/PEGDMA), in order to enhance the nanofiller adhesion and compatibility with the polymer matrix, and in the same time to increase the crosslinking density. The covalent modification of GO-COOH was proved by Fourier-transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA) and Raman spectroscopy. The mechanical properties, water uptake capacity, morphology, biodegradability, mineralization and in vitro cytotoxicity of PPF/PEGDMA hybrid materials containing GO@HEMA were investigated. A 14-fold increase of the compressive modulus and a 2-fold improvement in compressive strength were observed after introduction of the nanofiller. Moreover, the decrease in sol fraction and solvent swelling in case of the hybrid materials containing GO@HEMA suggests an increase of the crosslinking density. SEM images illustrate an exfoliated structure at lower nanofiller content and a tendency for agglomeration at higher concentrations. Finally, the synthesized hybrid materials proved non-cytotoxic to murine pre-osteoblast cells and induced the formation of hydroxyapatite crystals under mineralization conditions.

show abstract

Section: Resultsmentioning

confidence: 99%

“…Bromine (0.1 mL) was carefully added in the outer tube. After 4 h at room temperature, the inner vial was taken out and transferred to the vacuum oven where it was kept at 5 mmHg for 24 h 22 .…”

Section: Methodsmentioning

confidence: 99%

Hema-Functionalized Graphene Oxide: a Versatile Nanofiller for Poly(Propylene Fumarate)-Based Hybrid Materials

Vasile

Pandele

Andronescu

et al. 2019

Sci Rep

View full text Add to dashboard Cite

show abstract

“…The high-resolution C 1s XPS spectra of ovi-POSS, PPVIm, and SiO 0.71 C 1.95 N 0.47 vary, as shown in Figure d. For ovi-POSS, all carbon atoms combine in the form of CC with a binding energy at 284.1 eV, while two deconvolved peaks are observed in PPVIm and SiO 0.71 C 1.95 N 0.47 . One peak shifts to 284.8 eV associated with C–C, and the other shifts to 285.5 eV corresponding to C–N, further confirming the successful doping of the nitrogen element into the Si–O skeletons …”

Section: Methodsmentioning

confidence: 97%

“…For ovi-POSS, all carbon atoms combine in the form of C�C with a binding energy at 284.1 eV, while two deconvolved peaks are observed in PPVIm and SiO 0.71 C 1.95 N 0.47 . 24 One peak shifts to 284.8 eV associated with C−C, and the other shifts to 285.5 eV corresponding to C−N, further confirming the successful doping of the nitrogen element into the Si− O skeletons. 25 To verify lithium-ion compatibility of SiO 0.71 C 1.95 N 0.47 and evaluate its charge and discharge capacity, the complete cycle performance curve of this composite anode cycled between 0.01 and 3 V along with the corresponding coulombic efficiency is shown in Figure 5a.…”

Section: Methodsmentioning

confidence: 99%

Analysis of the Lithium Storage Mechanism in the SiO_x/C Composite Based on the Performance Variation Applied to a Lithium-Ion Battery

Zhang

Fan²,

Tan

et al. 2023

Energy Fuels

View full text Add to dashboard Cite

The SiO x /C composite, as a form of silicon-based materials, has been considered as an attractive alternative anode for next-generation lithium-ion batteries. The porous SiO 0.71 C 1.95 N 0.47 anode material exhibiting robust Si−O skeletons wrapped by carbon layers is successfully prepared and delivers an initial capacity of over 1700 mAh g −1 with an initial coulombic efficiency of 69.4% and favorable cycle life. Both Si (2p) X-ray photoelectron spectroscopy (XPS) and 29 Si nuclear magnetic resonance (NMR) demonstrate the existence of SiO 4 and SiO 3 C units as main lithium storage sites in the original state. The XPS curve moved toward the direction of the binding energy decreasing with NMR spectra shifting to a high field after the first lithiation process. The massive capacity loss during the first discharge and charge cycle results from the formation of irreversible Li silicate (Li 2 SiO 4 ). The fluctuation of the charge and discharge capacity, including a persistent decline during the first 30 cycles and a continuous elevation in the following 400 cycles, could be attributed to the participated degree of reversible Li silicate (Li 2 SiO 3 and Li 2 Si 2 O 5 ) in the delithiation process. The Si−O skeletons are gradually corroded and ultimately destroyed in the final 400 cycles, leading to the sharp drop of the cycling performance of the half-cell.

show abstract

“…Recent works conducted by several investigators showed that the phase contrast images were highly effective for estimating structural inhomogeneity of materials [5]. The chemical composition of the fracture surfaces was studied by techniques of XPS-analysis described in [6].…”

Section: Experimental Methods and Specimensmentioning

confidence: 99%

Investigation of Structural Hierarchy of Nanoceramics Compacted by Dry Pressing under Powerful Ultrasound Action

Хасанов

Karban

Двилис³

2004

KEM

View full text Add to dashboard Cite

Abstract. AFM techniques were used to investigate the microstructure, internal grain structure and intergrain interfaces of zirconia nanostructured ceramics sintered from green compacts being compacted by the common uniaxial dry compacting of nanopowders and under powerful ultrasound action. It was confirmed an essential influence of nanopowder compacting conditions on microstructure of sintered ceramics.

show abstract

Bromination reaction in C  C double bond determination by XPS

Cited by 7 publications

References 9 publications

Hema-Functionalized Graphene Oxide: a Versatile Nanofiller for Poly(Propylene Fumarate)-Based Hybrid Materials

Hema-Functionalized Graphene Oxide: a Versatile Nanofiller for Poly(Propylene Fumarate)-Based Hybrid Materials

Analysis of the Lithium Storage Mechanism in the SiO_x/C Composite Based on the Performance Variation Applied to a Lithium-Ion Battery

Investigation of Structural Hierarchy of Nanoceramics Compacted by Dry Pressing under Powerful Ultrasound Action

Contact Info

Product

Resources

About

Bromination reaction in C  C double bond determination by XPS

Cited by 7 publications

References 9 publications

Hema-Functionalized Graphene Oxide: a Versatile Nanofiller for Poly(Propylene Fumarate)-Based Hybrid Materials

Hema-Functionalized Graphene Oxide: a Versatile Nanofiller for Poly(Propylene Fumarate)-Based Hybrid Materials

Analysis of the Lithium Storage Mechanism in the SiOx/C Composite Based on the Performance Variation Applied to a Lithium-Ion Battery

Investigation of Structural Hierarchy of Nanoceramics Compacted by Dry Pressing under Powerful Ultrasound Action

Contact Info

Product

Resources

About

Analysis of the Lithium Storage Mechanism in the SiO_x/C Composite Based on the Performance Variation Applied to a Lithium-Ion Battery