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.

Enzymatic Synthesis and Characterization of an Water-Soluble Conducting Poly (1,4-Diaminobenzene-Acrylic Acid)

2010 ◽  
Vol 148-149 ◽  
pp. 118-125
Author(s):  
Jia Yu Zeng ◽  
Wei Bo Zhang ◽  
Shi Qi Liao ◽  
Dong Xia Zhang ◽  
Yun Pu Wang ◽  
...  
Keyword(s):  
Acrylic Acid ◽  
Photoelectron Spectroscopy ◽  
Water Solubility ◽  
Thermo Gravimetric Analysis ◽  
Decomposition Temperature ◽  
Water Soluble ◽  
Gravimetric Analysis ◽  
Ft Ir ◽  
Acid Catalyzed

A polymerization between 1,4-diaminobenzene (PPD) and acrylic acid catalyzed by Horseradish Perodxidase (HRP) in an water buffer will be described in this article. The effects of the concentration of H2O2, the ratio of the acrylic acid to PPD, the pH of the buffer, and the reaction time of polymerization were investigated. Compared with conventional methods, the synthesis is simple and the conditions are mild. The conductivity, UV-vis spectra, FT-IR spectra, X-ray photoelectron spectroscopy (XPS), and the thermo-gravimetric analysis (TGA) of the resulting polymer were investigated also. The results show that the synthesized polymer (PAnI) is a self-doped poly(1,4-diaminobenzene-acrylic acid) with 1,4-disubstituted aromatic ring, and a higher electro-activity, water-solubility, its decomposition temperature is 498.8 °C.

Nanorods of Cobalt Oxide: Study on its Morphology with Varied Sonication Time

2013 ◽  
Vol 678 ◽  
pp. 203-206
Author(s):  
A. Alex John Thangapaul ◽  
V. Sherly Arpuda Kiruba ◽  
R. Nivea ◽  
T. Viji ◽  
K. Thiyagarajan ◽  
...  
Keyword(s):  
Cobalt Oxide ◽  
Materials Science ◽  
Metal Oxide Nanoparticles ◽  
Thermo Gravimetric Analysis ◽  
Cost Effective ◽  
Oxide Nanoparticles ◽  
Gravimetric Analysis ◽  
Sonication Time ◽  
Cobalt Oxide Nanoparticles ◽  
Weight Percentage

Nanomaterials research has become a major attraction in the field of advanced materials research in the area of Physics, Chemistry, and Materials Science. Biocompatible and chemically stable magnetic metal oxide nanoparticles have biomedical applications that includes drug delivery, cell and DNA separation, gene cloning, magnetic resonance imaging (MRI). This research is aimed at the fabrication of magnetic cobalt oxide nanoparticles using a safe, cost effective, and easy to handle technique that is capable of producing nanoparticles free of any contamination. Nanostructured Cobalt oxide powder was prepared by sonication method using ultrasonicator. Effect of sonication for different time intervals, on the morphology of cobalt oxide nanostructures was extensively studied. The morphology of the nanorods were very much affected by the sonication time, it was found that with an increase in sonication time, the length of the nanorods seem to considerably increase at the same time an agglomeration effect comes in to action and the rods form bundle like structures. These cobalt oxide nanorods were characterized using X-ray Diffraction characterization (XRD) and it revealed a cubic structure. Weight percentage of cobalt oxide was confirmed by thermo gravimetric analysis (TGA).

scholarly journals Chemical and Physical Properties of Cassava Starch–CM-Chitosan–Acrylic Acid Gel Copolymerization by Gamma Irradiation

2014 ◽  
Vol 14 (1) ◽  
pp. 37-42
Author(s):  
Gatot Trimulyadi Rekso
Keyword(s):  
Acrylic Acid ◽  
Irradiation Dose ◽  
Thermo Gravimetric Analysis ◽  
Gravimetric Analysis ◽  
Γ Irradiation ◽  
Equilibrium Degree ◽  
Preparation Conditions ◽  
Gel Fraction ◽  
Gelatinized Starch ◽  
Acid Gel

Starch is a renewable natural polymer that can be decomposed easily in the environment and can be modified to various applications such as biomedical, agricultural and pharmaceutical applications. Copolymerization of gelatinized starch–CM-chitosan and acrylic acid (AAc) in aqueous medium using γ-irradiation was carried out. The preparation conditions, such as irradiation dose and AAc concentration were investigated. The copolymers were characterized by FTIR spectroscopy, thermo-gravimetric analysis (TGA) and scanning electron microscopy (SEM). The results show that by increasing of irradiation dose the gel fraction increases till the dose of 15 kGy. Above the stating dose the gel fraction decreases. The Equilibrium Degree of Swelling (EDS) value slightly increases with increasing irradiation dose and after dose of 15 kGy is decreasing. The swelling of starch–CM-chitosan–AAc hydro gels reduced as the gel content increases. The results indicated that the optimum condition for obtaining hydro gels with desirable properties was irradiated at dose of 15 kGy. The results indicated that SEM revealed that the higher the dose, the lower the copolymer pore size. The starch–CM-chitosan–AAc copolymers have thermal stability higher than that for starch individually.

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 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 New water-based flexographic ink based on new ter-polymer nano-particles as eco-friendly binders – Part II

2020 ◽  
Vol 49 (6) ◽  
pp. 473-482
Author(s):  
H. Abd El-Wahab ◽  
G.A. Meligi ◽  
M.G. Hassaan ◽  
L. Lin
Keyword(s):  
Water Resistance ◽  
Low Cost ◽  
Thermo Gravimetric Analysis ◽  
Gel Permeation Chromatography ◽  
Nano Particles ◽  
Gravimetric Analysis ◽  
Adhesion Properties ◽  
Content Type ◽  
Low Viscosity ◽  
Water Based

Purpose The purpose of this study is to prepare, characterise and evaluate nano-emulsions of ter-polymers of various compositions as eco-friendly binders for flexographic ink industry. Design/methodology/approach Various nano-emulsions of ter-polymers were prepared based on Vinyl acetate, Vinyl Versatate, butyl acrylate, acrylic acid and acrylamide monomers by means of a conventional seeded emulsion polymerisation technique, using K2S2O8 as the initiator. The characterisation of the prepared emulsions was performed using Fourier transform infrared, thermo-gravimetric analysis, gel permeation chromatography and transmission electron microscopy. A selection of co-polymers and ter-polymers were formulated with pigments and additional ingredients, as water-based flexographic inks. The inks were characterised for their rheological properties, pH, degree of dispersion, water-resistance and colour density. Findings It was found that the low viscosity of the prepared polymers may reduce the film thickness of the flexographic inks and may also increase the spreading of the ink on the surface. As a result, stable modified poly acrylate-based latex with improved physico-mechanical properties was obtained. The prepared latexes showed improved properties such as enhanced thermal stability and better water resistance. The effect of the emulsifier type on the properties of the resulting emulsion latexes and their corresponding films were investigated. Also, as the hydrophobic monomer increases, so does the colour density and increasing the binder ratio enhances the gloss values. The improving in gloss values were obtained and provide excellent adhesion properties for both the pigment particles and the base paper. Research limitations/implications The study focusses on the preparation of new water-based ter-polymer nano-particles and their use as eco-friendly binders for flexographic ink industry. Ink formulations based on other different type emulsion polymers could also be studied to assess the applicability of the ink formulation system found for other binders. Practical implications The ink formulations developed could find use in industrial-scale printing. Originality/value Eco-friendly environment and low-cost ink formulations for printing on paper substrates are novel.

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.

Surface Characterization of Poly(acrylic acid) Grafted to Photo-oxidized Perfluorosulfonic Acid Membrane Used in Fuel Cells

2010 ◽  
Vol 1269 ◽  
Author(s):  
Alla Bailey ◽  
Fei Lu ◽  
Ameya Khot ◽  
Shahida Hussain ◽  
Kyle W. Rugg ◽  
...  
Keyword(s):  
Acrylic Acid ◽  
Photoelectron Spectroscopy ◽  
Surface Characterization ◽  
Microwave Plasma ◽  
Perfluorosulfonic Acid ◽  
Photo Oxidation ◽  
Modified Surface ◽  
Surface Modified ◽  
Poly Acrylic Acid

AbstractPerfluorosulfonic acid membrane (Nafion®-117) was first surface modified with atmospheric pressure UV photo-oxidation or low-pressure vacuum UV photo-oxidation downstream from an Ar microwave plasma, and then graft polymerized with acrylic acid. X-ray photoelectron spectroscopy (XPS) was used to analyze the modified Nafion surface and poly(acrylic acid) grafted to the modified surface.

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).

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