Synthesis and characterization of hydrogen-bond acidic functionalized graphene

2014 ◽  
Vol 07 (04) ◽  
pp. 1450043 ◽  
Author(s):  
Liu Yang ◽  
Qiang Han ◽  
Yong Pan ◽  
Shuya Cao ◽  
Mingyu Ding
Keyword(s):  
Photoelectron Spectroscopy ◽  
Thermo Gravimetric Analysis ◽  
Synthesis Method ◽  
Phenyl Group ◽  
Nerve Agent ◽  
Potential Candidate ◽  
Gravimetric Analysis ◽  
Functionalized Graphene ◽  
Functionalized Materials ◽  
Diazonium Reaction

Hexafluoroisopropanol phenyl group functionalized materials have great potential in the application of gas-sensitive materials for nerve agent detection, due to the formation of strong hydrogen-bonding interactions between the group and the analytes. In this paper, take full advantage of ultra-large specific surface area and plenty of carbon–carbon double bonds and hexafluoroisopropanol phenyl functionalized graphene was synthesized through in situ diazonium reaction between - C = C - and p-hexafluoroisopropanol aniline. The identity of the as-synthesis material was confirmed by transmission electron microscopy, Raman spectroscopy, ultraviolet visible spectroscopy, X-ray photoelectron spectroscopy and thermo gravimetric analysis. The synthesis method is simply which retained the excellent physical properties of original graphene. In addition, the novel material can be assigned as an potential candidate for gas sensitive materials towards organophosphorus nerve agent detection.

scholarly journals Preparation and structure of SiOCN fibres derived from cyclic silazane/poly-acrylic acid hybrid precursor

2019 ◽  
Vol 6 (10) ◽  
pp. 190690
Author(s):  
Zhongkan Ren ◽  
Christel Gervais ◽  
Gurpreet Singh
Keyword(s):  
Acrylic Acid ◽  
Photoelectron Spectroscopy ◽  
Thermo Gravimetric Analysis ◽  
Ceramic Matrix Composite ◽  
Linear Structure ◽  
Cost Effective ◽  
Gravimetric Analysis ◽  
Low Viscosity ◽  
Hybrid Precursor ◽  
Poly Acrylic Acid

Ceramic matrix composite (CMC) materials have been considered a desired solution for lightweight and high-temperature applications. Simultaneously, among all different CMC reinforcements, polymer-derived ceramic (PDC) fibres have gained attention for the intrinsic thermal stability and mechanical strength with simple and cost-effective synthesis techniques. Here, carbon-rich SiOCN fibres were synthesized via hand-drawing and polymer pyrolysis of a hybrid precursor of 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasilazane (TTCSZ) and poly-acrylic acid (PAA). The type of silazane reported in this work is considered as a major precursor for SiCN; however, it is unspinnable, due to its unfavourable physical properties (low viscosity) and chemical structure (cyclic rather than linear structure). The introduction of PAA to TTCSZ to create a hybrid precursor remarkably improved the spinnability of the silazane and should be widely applicable to other unspinnable PDC pre-ceramic polymers. Investigations on the structural and compositional development of the fibres were mainly conducted via Raman spectroscopy, Fourier-transform infrared spectroscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, nuclear magnetic resonance and thermo-gravimetric analysis to determine spinnability, free carbon content, cross-linking and pyrolysis behaviour of the fibres, respectively.

scholarly journals 3D Printed Silicone Meniscus Implants: Influence of the 3D Printing Process on Properties of Silicone Implants

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2136
Author(s):  
Eric Luis ◽  
Houwen Matthew Pan ◽  
Anil Kumar Bastola ◽  
Ram Bajpai ◽  
Swee Leong Sing ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Weight Bearing ◽  
Thermo Gravimetric Analysis ◽  
Silicone Implants ◽  
Osteoarthritis Of The Knee ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Hydrogel Scaffolds ◽  
Custom Made ◽  
3D Printed

Osteoarthritis of the knee with meniscal pathologies is a severe meniscal pathology suffered by the aging population worldwide. However, conventional meniscal substitutes are not 3D-printable and lack the customizability of 3D printed implants and are not mechanically robust enough for human implantation. Similarly, 3D printed hydrogel scaffolds suffer from drawbacks of being mechanically weak and as a result patients are unable to execute immediate post-surgical weight-bearing ambulation and rehabilitation. To solve this problem, we have developed a 3D silicone meniscus implant which is (1) cytocompatible, (2) resistant to cyclic loading and mechanically similar to native meniscus, and (3) directly 3D printable. The main focus of this study is to determine whether the purity, composition, structure, dimensions and mechanical properties of silicone implants are affected by the use of a custom-made in-house 3D-printer. We have used the phosphate buffer saline (PBS) absorption test, Fourier transform infrared (FTIR) spectroscopy, surface profilometry, thermo-gravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM) to effectively assess and compare material properties between molded and 3D printed silicone samples.

scholarly journals Synthesis and catalytic properties of nitrogen-containing carbon nanotubes

2021 ◽  
Vol 12 (2) ◽  
pp. 135-143
Author(s):  
Yu. I. Sementsov ◽  
◽  
O. A. Cherniuk ◽  
S. V. Zhuravskyi ◽  
Wang Bo ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Hydrogen Peroxide ◽  
Photoelectron Spectroscopy ◽  
Direct Synthesis ◽  
Synthesis Method ◽  
Total Content ◽  
Carbon Matrix ◽  
Intensity Increase ◽  
Gravimetric Analysis ◽  
Catalytically Active

Nitrogen-containing carbon nanotubes (CNTs) were synthesized by the CVD method on oxide catalysts of Al-Fe-Mo-O by adding acetonitrile or ethylenediamine to the carbon source (propylene), or completely replacing it, as well as impregnating the original CNTs with urea, followed by heat treatment. The structure of nitrogen-containing CNTs (N-CNT) was characterized by the method of Raman scattering, transmission electron microscopy (TEM), differential thermal and gravimetric analysis (DTA, DTG) and X-ray photoelectron spectroscopy (XPS). The influence of the synthesis method on the number and chemical state of nitrogen heteroatoms in the structure of the carbon matrix is found. According to the TEM, nitrogen-containing CNTs have a characteristic bamboo-like structure, which is less perfect compared to the structure of the original CNTs: the characteristic Raman bands (G and D) are shifted to higher frequencies, their half-width and band D intensity increase relative to G. This is also manifested in the lower thermal stability of nitrogen-containing CNTs. According to the XPS, the direct synthesis of nitrogen-containing CNTs increases the total content of nitrogen atoms and the proportion of pyrrolic and quaternary nitrogen against the background of a significant decrease in the amount of pyridinic form. This can be explained by the fact that nitrogen is evenly distributed throughout the carbon matrix of CNTs, and during nitriding of CNTs with urea, nitrogen is included mainly in the surface layers and defects, because the pyridine form is characteristic of the edge location of the nitrogen atom in the graphene plane.The catalytic effect of multilayer nitrogen-containing carbon nanotubes (N-CNT) on the kinetics of decomposition of hydrogen peroxide in aqueous solutions at different pH values is considered. It is concluded that the method of direct synthesis of nitrogen-containing CNTs allows to obtain more catalytically active carbon nanotubes containing more nitrogen, mainly pyrrolic and quaternary type. It has been found that regardless of the method of synthesis, the maximum catalytic activity in the decomposition of hydrogen peroxide is observed at pH 7.

scholarly journals Effects of Platinum and Palladium Metals on Ni/Mg1-xZrxO Catalysts in the CO2 Reforming of Methane

2018 ◽  
Vol 13 (2) ◽  
pp. 295 ◽  
Author(s):  
Faris Jasim Abdulridha Al-Doghachi
Keyword(s):  
Photoelectron Spectroscopy ◽  
Thermo Gravimetric Analysis ◽  
Coke Formation ◽  
Dry Reforming Of Methane ◽  
Precipitation Method ◽  
Cubic Phase ◽  
Gravimetric Analysis ◽  
Co2 Reforming ◽  
X Ray ◽  
Co2 Reforming Of Methane

Nickel, palladium, and platinum catalysts (1 wt.% each) supported on MgO and MgZrO to prepare Pt,Pd,Ni/Mg1-xZrxO catalysts (where x = 0, 0.03, 0.07, and 0.15), were synthesized by using co-precipitation method with K2CO3 as the precipitant. X-ray diffraction (XRD), X-ray fluorescence (XRF), X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET), transmission electron microscopy (TEM), H2-temperature programmed reduction (H2-TPR), and thermo gravimetric analysis (TGA) were employed to observe the characteristics of the prepared catalysts. The Pt,Pd,Ni/Mg0.85Zr0.15O showed the best activity in dry reforming of methane (DRM) with 99 % and 91 % for CO2 and CH4 conversions, respectively and 1.28 for H2/CO ratio at temperature 900 °C and 1:1 of CH4:CO2 ratio. The stability of Pt,Pd,Ni/Mg0.85Zr0.15O catalyst in the presence and absence of low stream 1.25 % oxygen was investigated. Carbon formation and amount in spent catalysts were examined by TEM and TGA in the presence of stream oxygen. The results showed that the amount of carbon was suppressed and negligible coke formation (less than 3 %) was observed. Several effects were observed with ZrO2 use as a promoter in the catalyst. Firstly, the magnesia cubic phase stabilized. Secondly, thermal stability and support for basicity increased. Thirdly, carbon deposition and the reducibility of Ni2+, Pd2+, and Pt2+ ions decreased. Copyright © 2018 BCREC Group. All rights reservedReceived: 25th October 2017; Revised: 2nd January 2018; Accepted: 18th January 2018; Available online: 11st June 2018; Published regularly: 1st August 2018How to Cite: Al-Doghachi, F.A.J. (2018). Effects of Platinum and Palladium Metals on Ni/Mg1-xZrxO Catalysts in the CO2 Reforming of Methane. Bulletin of Chemical Reaction Engineering & Catalysis, 13 (2): 295-310 (doi:10.9767/bcrec.13.2.1656.295-310) 

scholarly journals Solid-State Compounding for Recycling of Sawdust Waste into Green Packaging Composites

Processes ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1386
Author(s):  
Rula M. Allaf ◽  
Mohammad Futian
Keyword(s):  
Solid State ◽  
Thermo Gravimetric Analysis ◽  
Contact Angles ◽  
Raw Material ◽  
Potential Candidate ◽  
Gravimetric Analysis ◽  
Water Contact ◽  
Elongation At Break ◽  
Green Packaging ◽  
Thermal Stability Of

The present study explores solid-state cryomilling for the compounding of green composites. Herein, wood plastic composites (WPCs) composed of sawdust (SD) and poly(ε-caprolactone) (PCL) with various compositions were prepared. Two compounding techniques, namely, extrusion and cryomilling, were utilized to prepare WPC raw material pellets and powders, respectively, for comparison purposes. Flat pressing was further utilized to prepare WPC films for testing. Morphological, structural, thermal, mechanical, and surface wettability properties were investigated. Results indicate the advantages of cryomilling in producing WPCs. Scanning electron microscopy (SEM) along with optical micrographs revealed well ground SD particles and uniform distribution in the PCL matrix. Tensile strength and elongation at break of the composites declined with increasing SD content, however, the modulus of elasticity significantly increased. Water contact angles averaged less than 90°, implying partial wetting. Visual observations and thermo-gravimetric analysis (TGA) indicated thermal stability of composites during processing. In conclusion, PCL/SD WPC is a potential candidate to replace conventional plastics for packaging applications. This would also provide a much better utilization of the currently undervalued wood waste resources.

Mechanisms on formation of hierarchically porous carbon and its adsorption behaviors

2016 ◽  
Vol 74 (1) ◽  
pp. 266-275 ◽  
Author(s):  
Jie Liu ◽  
Lingxia Hao ◽  
Wenzhen Qian ◽  
Yu-Feng He ◽  
Rong-Min Wang
Keyword(s):  
Activated Carbon ◽  
Electron Microscope ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Photoelectron Spectroscopy ◽  
Thermo Gravimetric Analysis ◽  
Gravimetric Analysis ◽  
Hierarchically Porous ◽  
Adsorption Behaviors

Using simple one-step carbonization-activation, the residues of paulownia flowers are employed as a precursor to prepare hierarchically porous activated carbon. After investigating the optimum conditions, the obtained paulownia flowers based activated carbon (PFAC) is characterized by Fourier transform infrared spectroscopy, scanning electron microscope, transmission electron microscope, Brunauer–Emmett–Teller specific surface area analysis (SBET), thermo gravimetric analysis, and X-ray photoelectron spectroscopy. The PFAC owns a high specific surface area of 1,053 m2/g as well as a hierarchically porous structure with a combination of micro-, meso- and macropores. The pore-forming mechanism is discussed according to results of characterization. Using methylene blue as model dye, the adsorption behaviors of PFAC were investigated. We found that the dye could be rapidly adsorbed by hierarchically porous PFAC, and the adsorption capacity of PFAC reached 300 mg/g.

Characterisation of Hydroxyapatite/Bacterial Cellulose Nanocomposites

2009 ◽  
Vol 17 (6) ◽  
pp. 353-358 ◽  
Author(s):  
Shengnan Zhang ◽  
Guangyao Xiong ◽  
Fang He ◽  
Yuan Huang ◽  
Yulin Wang ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Bacterial Cellulose ◽  
Photoelectron Spectroscopy ◽  
Thermo Gravimetric Analysis ◽  
Hydroxyl Groups ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Cellulose Nanocomposites

A novel nanocomposite material consisting of hydroxyapatite (HAp) deposited on a phosphorylated bacterial cellulose (BC) has been synthesised via a biomimetic route. X-ray photoelectron spectroscopy (XPS) showed that phosphate groups were successfully introduced to the hydroxyl groups of BC by phosphorylation reaction to promote the growth of calcium phosphate. Transmission electron microscopy (TEM) and the corresponding selected area electron diffraction (SAED) patterns of HAp/BC demonstrated that HAp crystals wrap the surfaces of BC fibres. In this work, HAp/BC nanocomposites were studied using thermo-gravimetric analysis (TGA) and differential scanning calorimetry (DSC). The TGA result suggested that HAp/BC nanocomposite, similar to natural bone in terms of composition, contained carbonate ions, in agreement with our previous Fourier transform infrared (FTIR) spectroscopy results. Thermal behaviour differences between BC and HAp/BC were observed by differential scanning calorimetry (DSC). The thermal stability of HAp/BC obtained from DSC showed an improvement when compared to that of a pure BC sample.

Temperature Stability Of Plasma Polymerized Antiadhesive Coatings

1998 ◽  
Vol 544 ◽  
Author(s):  
W. Michaeli ◽  
R. Dahlmann ◽  
I. Fonteiner
Keyword(s):  
Surface Tension ◽  
Photoelectron Spectroscopy ◽  
Thermo Gravimetric Analysis ◽  
Temperature Stability ◽  
Polymer Coatings ◽  
Gravimetric Analysis ◽  
Angle Measurements ◽  
Wide Range ◽  
Contact Angle Measurements ◽  
Thermal Stability Of

AbstractBy means of microwave-assisted plasma polymerization it is possible to deposit polymer coatings on different surfaces such as plastics or metals. The surface tension can be influenced in a wide range. However, many applications require a high thermal stability of such low surface tension layers. Therefore, the influence of variations of the process parameters on temperature stability of such layers is examined. The produced layers were studied regarding their chemical and physical characteristics under temperature influence by means of contact angle measurements, xray photoelectron spectroscopy (XPS), thermo gravimetric analysis (TGA) combined with Fouriertransformed infrared spectroscopy (FTIR). Fluorine containing monomers offer good perspectives. Up to temperatures of approx. 200°C the antiadhesivity of these coatings is adjustable to values close to those of poly(tetrafluoroethylene) (PTFE).

Liquid-State Synthesis and Properties of Fluorescent Conducting Polymers: α, βi-SiW11AlIII/Polyaniline

2013 ◽  
Vol 561 ◽  
pp. 13-18
Author(s):  
Wan Li Yang ◽  
Qing Wen Wang ◽  
Rong Hua Ma
Keyword(s):  
Thermal Stability ◽  
Ir Spectroscopy ◽  
Fluorescence Spectroscopy ◽  
Hybrid Materials ◽  
Liquid State ◽  
Thermo Gravimetric Analysis ◽  
Synthesis Method ◽  
Average Diameter ◽  
Gravimetric Analysis ◽  
Thermo Gravimetric

Four polyaniline hybrid materials were prepared by liquid-state synthesis method in the presence of dopant which synthesized by transition metal mono-substituted Keggin structure silicotungstate anions α, βi-[SiW11Al (H2O)O39]4-.The polyaniline hybrid materials were characterized by elemental analysis, IR spectroscopy, fluorescence spectroscopy, scanning electeon microscopy (SEM) and thermo gravimetric analysis, the properties of which such as thermal stability and conducting behavior were studied. It proved that the average diameter was 100nm, the conductivity was 9×10-2s·cm-1 and the flourescence property was better.

scholarly journals Dehydration of Fructose to 5-HMF over Acidic TiO2 Catalysts

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1178 ◽  
Author(s):  
Maria Luisa Testa ◽  
Gianmarco Miroddi ◽  
Marco Russo ◽  
Valeria La Parola ◽  
Giuseppe Marcì
Keyword(s):  
Photoelectron Spectroscopy ◽  
Thermo Gravimetric Analysis ◽  
Process Condition ◽  
Textural Properties ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
X Ray ◽  
Catalytic Sites ◽  
Lower Temperature

Different solid sulfonic titania-based catalysts were investigated for the hydrothermal dehydration of fructose to 5-hydroxymethylfurfural (5-HMF). The catalytic behavior of the materials was evaluated in terms of fructose conversion and selectivity to 5-HMF. The surface and structural properties of the catalysts were investigated by means of X-ray diffraction (XRD), N2 adsorption isotherms, thermo-gravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS) and acid capacity measurements. Special attention was focused on the reaction conditions, both in terms of 5-HMF selectivity and the sustainability of the process, choosing water as the solvent. Among the various process condition studied, TiO2-SO3H catalyzed a complete conversion (99%) of 1.1M fructose and 5-HMF selectivity (50%) and yield (50%) at 165 °C. An important improvement of the HMF selectivity (71%) was achieved when the reaction was carried out by using a lower fructose concentration (0.1M) and lower temperature (140 °C). The catalytic activities of the materials were related to their acid capacities as much as their textural properties. In particular, a counterbalance between the acidity and the structure of the pores in which the catalytic sites are located, results in the key issue for switch the selectivity towards the achievement of 5-HMF.

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