Synthesis and Characterization of Covalent Organic Polymer

2016 ◽  
Vol 701 ◽  
pp. 270-274
Author(s):  
Siew Pei Lee ◽  
Nurhayati Mellon ◽  
Tuck Khein Lau ◽  
Azmi Mohd Shariff ◽  
Jean Marc Leveque
Keyword(s):  
Low Cost ◽  
Lower Surface ◽  
Organic Polymer ◽  
Gravimetric Analysis ◽  
New Class ◽  
Degradation Temperature ◽  
Infra Red ◽  
One Step ◽  
The Difference

Development of covalent organic polymer (COP) is a potential new class of adsorbent for gas separation due to their good hydrothermal stability, chemical tuning flexibility and low cost. COP-1 was prepared via one-step polycondensation of cyanuric chloride and piperazine under catalyst free and N2 atmosphere condition. The properties of COP-1 were characterized using several analytical methods such as Fourier Transform Infra-Red (FTIR), solid Nuclear Magnetic Resonance (s-NMR), Thermal gravimetric analysis (TGA) and N2 adsorption and desorption measurement. The C-N bond of COP-1 which has non-rigid framework was successfully linked in this study. It is found that COP-1 has low thermal degradation temperature i.e. 483 K. As compared to literature, lower surface area (75.5 m2/g) and slightly large pore size (8 nm) are noticed. The difference of physical properties of COP-1 synthesized between in this study and literature revealed the challenge of reproducibility for COP-1.

Synthesis and Characterization of the Bismaleimides Containing Aliphatic-ether Chain for Microelectronics Application

e-Polymers ◽  
2006 ◽  
Vol 6 (1) ◽  
Author(s):  
J. L. Feng ◽  
C. Y. Yue ◽  
K. S. Chian
Keyword(s):  
Chain Length ◽  
Thermo Gravimetric Analysis ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Thermo Gravimetric ◽  
Degradation Temperature ◽  
Dielectric Thermal Analysis ◽  
Aliphatic Ether ◽  
Synthetic Reaction

AbstractThis project aims to develop and characterize a series of bismaleimide (BMI) polymers based on maleic anhydride and aliphatic-ether diamines. The effects of varying the chain length of aliphatic-ether diamines on the resultant bismaleimide systems were evaluated so that their suitability for microelectronics applications could be evaluated. The synthetic reaction and properties of the bismaleimide materials were investigated using Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), Thermo- Gravimetric Analysis (TGA), Dielectric Thermal Analysis (DEA) and rheometry. Results showed that thermal, dielectric and rheological properties were all affected by the main chain length of BMI. The magnitude of the dielectric constant at 100 kHz increases with the increasing chain length. The curing peak temperature, curing heat and degradation temperature of BMI, all decrease with the increasing chain length.

Growth and Characterization of Cobalt-filled Carbon Nanotubes Prepared by a Simple Catalytic Method

2003 ◽  
Vol 776 ◽  
Author(s):  
Xicheng Ma ◽  
Yuanhua Cai ◽  
Xia Li ◽  
Ning Lun ◽  
Shulin Wen
Keyword(s):  
Carbon Nanotubes ◽  
Metallic Nanoparticles ◽  
Low Cost ◽  
Catalytic Method ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
High Resolution Tem ◽  
One Step

AbstractHigh-quality cobalt-filled carbon nanotubes (CNTs) were prepared in situ in the decomposition of benzene over Co/silica-gel nano-scale catalysts. Unlike the previous reports, the catalysts needn't be pre-reduced prior to the forming of Co-filled CNTs, thus the advantage of this method is that Co-filled CNTs can be produced in one step, at a relatively low cost. Transmission electron microscopy (TEM) investigation showed that the products contained abundance of CNTs and most of them were filled with metallic nanoparticles or nanorods. High-resolution TEM (HRTEM), selected area electron diffraction (SAED) patterns and energy dispersive X-ray spectroscopy (EDS) confirmed the presence of Co inside the nanotubes. The encapsulated Co was further identified always as high temperature alpha-Co phase with fcc structure, which frequently consists of twinned boundaries and stacking faults. Based on the experimental results, a possible growth mechanism of the Co-filled CNTs was proposed.

scholarly journals Influence of the calibration on experimental UV index at a midlatitude site, Granada (Spain)

2010 ◽  
Vol 3 (6) ◽  
pp. 5645-5670
Author(s):  
M. Antón ◽  
J. E. Gil ◽  
A. Cazorla ◽  
J. M. Vilaplana ◽  
F. J. Olmo ◽  
...  
Keyword(s):  
Calibration Method ◽  
Conversion Factors ◽  
Uv Index ◽  
Calibration Methods ◽  
One Step ◽  
The Difference ◽  
Mean Differences ◽  
Experimental Values ◽  
The One

Abstract. The ultraviolet (UV) index is the variable most commonly used to inform the general public about the levels and potential harmful effects of UV radiation incident at Earth's surface. This variable is derived from the output signal of the UV radiometers applying conversion factors obtained by calibration methods. This paper focused on the influence of the use of two of these methods (called one-step and two-steps methods) on the resulting experimental UV Index (UVI) as measured by a YES UVB-1 radiometer located in a midlatitude station, Granada (Spain) for the period 2006–2009. In addition, it is also analyzed the difference with the UVI values obtained when the calibration factors provided by the manufacturer are used. For this goal, the detailed characterization of the UVB-1 radiometer obtained in the first Spanish calibration campaign of broadband UV radiometers at the "El Arenosillo" INTA station in 2007 is used. In addition, modeled UVI data derived from the LibRadtran/UVSPEC radiative transfer code are compared with the experimental values recorded at Granada for cloud-free conditions. The absolute mean differences between the measured and modeled UVI data at Granada are around 5% using the one-step and two-steps calibration methods. This result indicates the excellent performance of these two techniques for obtaining UVI data from the UVB-1 radiometer. In contrast, the application of the calibration factor supplied by the manufacturer produces a high overestimation (~14%) of the UVI values. This fact generates unreliable alarming high UVI data in summer when the manufacturer's factor is used. Thus, days with an extreme erythemal risk (UVI higher than 10) increase up to 46% of all cases measured between May and September at Granada when the manufacturer's factor is applied. This percentage is reduced to a more reliable value of 3% when the conversion factors obtained with the two-steps calibration method are used. All these results report about the need of a sound calibration of the broadband UV instruments in order to obtain reliable measurements.

scholarly journals Influence of Hybrid Sol-Gel Crosslinker on Self-Healing Properties for Multifunctional Coatings

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5382
Author(s):  
Guillaume Lollivier ◽  
Marie Gressier ◽  
Florence Ansart ◽  
Maëlenn Aufray ◽  
Marie-Joëlle Menu
Keyword(s):  
Sol Gel ◽  
Interface Layer ◽  
Hybrid Coatings ◽  
Organic Polymer ◽  
Self Healing ◽  
Oxide Interface ◽  
Protective Oxide ◽  
New Class ◽  
One Step

Self-healing polymers are a new class of material that has recently received a lot of attention because of the lifespan improvement it could bring to multiple applications. One of the major challenges is to obtain multifunctional materials which can self-heal and exhibit other interesting properties such as protection against corrosion. In this paper, the effect of the incorporation of an aminosilane on the properties of a self-healing organic polymer containing disulfide bond is studied on films and coatings for aluminium AA2024-T3 using simple one step in situ synthesis. Hybrid coatings with enhanced anticorrosion properties measured by EIS were obtained thanks to the formation of a protective oxide interface layer, while exhibiting wound closure after exposition at 75 °C. The thermal, mechanical and rheological properties of the films with different aminosilane amounts were characterized in order to understand the influence of the slight presence of the inorganic network. Stiffer and reprocessable hybrid films were obtained, capable to recover their mechanical properties after healing. The nanocomposite structure, confirmed by TEM, had a positive effect on the self-healing and stress relaxation properties. These results highlight the potential of sol-gel chemistry to obtain efficient anticorrosion and self-healing coatings.

Surface Bonding Graphene-Based Elastomeric Sensor: Preliminary Characterization of Adhesion Strength

2019 ◽  
Author(s):  
Salvatore Ameduri ◽  
Monica Ciminello
Keyword(s):  
Reference Strain ◽  
Low Cost ◽  
Graphite Powder ◽  
Free Edge ◽  
Lower Surface ◽  
Structural Integration ◽  
Filled Elastomer ◽  
Adhesive Penetration ◽  
Strength Characterization

Abstract This research intends to propose a structural integration methodology for a strain sensor based on nano-filled elastomer and its preliminary bonding strength characterization. To provide a good strength adhesion onto a structural component, a special mould was designed, made of Acrilonitrile butadiene styrene (ABS) material and realised with a 3D printing. This specific texture provided the lower surface of the elastomer (PDMS-matrix) with a special micro voids allowing for the adhesive penetration. The electrodes were made by simple conductive paste. To have a chemically compliant coupling between the elastomer and this paste, an off-the-shelf cheap neutral silicone was used. This paste was then made conductive by adding a low-cost graphite powder, obtained from a pencil lead. The test was realized with an aluminium beam in cantilever configuration. The load were applied at the free edge by means of calibrated masses of increasing weights. For each mass, the values of tip displacement and the resistance provided by the nano-filled elastomer and a reference strain gauge were logged for a set of 10 cycles. Obtained data clearly revealed that, all sensors exhibit coherent readouts with respect to the reference strain gauges and a quasi linear sensitivity curve in the whole range.

Atomic orbital-wise characterization of the vibronic attractive interaction in a model of an oxygen-containing organic polymer

1992 ◽  
Vol 70 (2) ◽  
pp. 427-433
Author(s):  
Akitomo Tachibana ◽  
Shigeru Ishikawa ◽  
Wataru Sahara ◽  
Tokio Yamabe
Keyword(s):  
Atomic Orbital ◽  
Vibronic Interaction ◽  
Organic Polymer ◽  
Coupling Constant ◽  
Phonon Coupling ◽  
Local Electron ◽  
Electron Pairing ◽  
Electron Phonon Coupling ◽  
The Difference

The extended local vibronic constant (ELVC) is introduced for the study of the strength of local electron pairing for superconductivity based on vibronic interaction using a model of an oxygen-containing organic polymer. The ELVC consists of the electrostatic part and the two-electron part, which originates in the response of the electron density to the nuclear vibration. It is found that the two-electron part has opposite sign to, and almost the same magnitude as, that of the electrostatic part. The difference between the ELVC and the Fock matrix derivative, which is related to the derivative of the Hückel parameters used as the electron–phonon coupling constant, is discussed. The vibronic interaction in the in-plane orbitals, which is characteristic of the interaction in a two-dimensional conductor, is also discussed. Keywords: vibronic interaction, superconductivity, local electron pairing, extended local vibronic constant, abinitio calculation.

Introducing Electrospray as a Potent Technique to Deliver Chitosan/pDNA Nanoparticles to Eukaryotic Cells

2021 ◽  
Vol 66 ◽  
pp. 73-84
Author(s):  
Farzaneh Saeedi Landi ◽  
Babak Negahdari ◽  
Fariba Esmaeili ◽  
Sedigheh Kolivand ◽  
Amir Amani
Keyword(s):  
Zeta Potential ◽  
Transfection Efficiency ◽  
Low Cost ◽  
Gene Transfection ◽  
Physicochemical Characterization ◽  
Entrapment Efficiency ◽  
Ratio Size ◽  
Agarose Electrophoresis ◽  
One Step

Electrospray technique has received increasing attentions for intracellular gene delivery as well as production of nanoparticles. In this study, chitosan/pDNA nanoparticles with N/P ratio of 5 were prepared and transferred to HEK293T cells by electrospray technique. Physicochemical characterization of prepared nanoparticles, including size, zeta potential and entrapment efficiency was performed and attachment of pDNA to chitosan was confirmed by gel agarose electrophoresis. Moreover, transfection efficiency was investigated using flow cytometry. MTT assay was performed for cell viability studies. Nanoparticles were prepared at three pDNA concentrations of 10, 55 and 100 μg/ml in fixed N/P ratio. Size of nanoparticles was obtained as 110, 188 and 240 nm, using DLS. SEM showed size of 102.34 ± 10.66 nm for samples having 55 μg/ml pDNA. Zeta potential and entrapment efficiency were +25 mv and 85±4%m respectively. The effect of pDNA concentration, electrospray time and incubation time on transfection efficiency was investigated using Box-Behnken design. Percent of GFP-positive cells was 41.05 ± 3.04% which was taken as an indicator of transfection efficiency. Transfection efficiency of this method was then compared with that of calcium phosphate (31.1 ± 2.4%), showing improved efficiency. Considering the fact that electrospray is an easy, low cost, one-step process which makes low damage to cells and produces monodispersed nanoparticles, the method is introduced as a fascinating approach in gene transfection.

Synthesis and study of a calixpyrrole-texaphyrin chimera: A new oligopyrrolic chloride anion receptor

2003 ◽  
Vol 07 (02) ◽  
pp. 97-104 ◽  
Author(s):  
Jonathan L. Sessler ◽  
Won-Seob Cho ◽  
Stephen P. Dudek ◽  
Lindsay Hicks ◽  
Vincent M. Lynch ◽  
...  
Keyword(s):  
Chloride Anion ◽  
Acetonitrile Solution ◽  
Titration Calorimetry ◽  
Anion Receptors ◽  
X Ray ◽  
New Class ◽  
One Step ◽  
Acid Catalyzed ◽  
High Yields

Reported here is the synthesis and characterization of a new class of macrocycle that represents a hybrid between texaphyrin and calixpyrrole. These polypyrrolic macrocycles were prepared in one step by the acid-catalyzed condensation between diformyl dipyrromethanes and o-phenylenediamines in high yields. The X-ray crystal structure of one of these new “chimeras” was solved. It reveals that the diprotonated Schiff-base macrocycle has a V-shape in which one chloride anion is bound. Isothermal titration calorimetry (ITC) studies served to confirm the ability of the hybrid macrocycles to bind chloride anion in acetonitrile solution. These compounds may be useful as easy-to-make anion receptors.

Fabrication, Mechanical Characterization and FTIR Spectroscopic Analysis of Fish Scale Reinforced Epoxy Composites

2012 ◽  
Vol 445 ◽  
pp. 889-892 ◽  
Author(s):  
Alok Satapathy ◽  
Manoj Kumar Pradhan ◽  
Debadutta Mishra ◽  
Amar Patnaik
Keyword(s):  
Power Plants ◽  
Spectroscopic Analysis ◽  
Low Cost ◽  
Conveyor Belt ◽  
Fresh Water Fish ◽  
Fish Scale ◽  
Matrix Composites ◽  
New Class ◽  
Housing Materials

This paper describes the processing and characterization of a new class of epoxy matrix composites reinforced with short fibers obtained from the scales of a fresh water fish (Labeo rohita). The functional groups involved in the formation of the resulting composite are identified. Fourier Transform Infrared (FTIR) spectroscopic analysis shows that the formation of hydrogen bonds occurring at the fiber-matrix interface between the oxygen atom of the epoxy and hydrogen atom of the polypeptide chain of fish scale is responsible for the formation of this new class of composites. These composites possess improved micro-hardness and exhibit tensile and flexural strengths marginally different from those of neat epoxy. These composites are expected to find applications as potential materials for conveyor belt rollers, pipes carrying pulverized coal in power plants, pump and impeller blades and also as low cost housing materials.

Analisis Karakterisasi Teknologi Direct Sequence Spread Spectrum Dan Frequency Hopping Spread Spectrum

2019 ◽  
Vol 2 (2) ◽  
pp. 129-138
Author(s):  
Fawzan Galib Abdul Karim Bawahab ◽  
Elvan Yuniarti ◽  
Edi Kurniawan
Keyword(s):  
Spread Spectrum ◽  
Communication Systems ◽  
Multiple Access ◽  
Frequency Hopping ◽  
Direct Sequence Spread Spectrum ◽  
Direct Sequence ◽  
Frequency Hopping Spread Spectrum ◽  
Two Systems ◽  
The Difference

Abstrak. Pada penelitian ini, telah dilakukan analisa karakterisasi pada teknologi Direct Sequence Spread Spectrum dan Frequency Hopping Spread Spectrum, sebagai salah satu teknik multiple-access pada sistem komunikasi. Karakterisasi dilakukan untuk mencari bagaimana cara meningkatkan keoptimalan kedua sistem tersebut, dalam mengatasi masalah interferensi dengan sistem dan channel yang sama. Dan juga untuk menentukan veriabel apa yang mempengaruhi keoptimalan kedua sistem tersebut. Karakterisasi dilakukan dengan menentukan variabel-variabel yang mempengaruhi keoptimalan keduanya. Hasil dari karakterisasi, diketahui variabel-variabel yang mempengaruhi kemampuan sistem DSSS yaitu nilai frekuensi spreading (). Sedangkan untuk sistem FHSS yaitu nilai frekuensi spreading ( dan ) dan selisih antara frekuensi hopping data dengan frekuensi hopping interferensi . Kata Kunci: BER, DSSS, FHSS, Interference, Spread spectrum. Abstract. In this study, characterization of Direct Sequence Spread Spectrum and Frequency Hopping Spread Spectrum technologies have been done, as one of the multiple-access techniques in communication systems. Characterization is done to find out how to improve the ability of the two systems, in solving interference problems with the same system and channel. And also to determine what veriabel affects the ability of the two systems. Characterization is done by determining the variables that affect the ability of both. The results of the characterization, known variables that affect the ability of the DSSS system are the spreading frequency value (). As for the FHSS system, the spreading frequency value ( and ) and the difference between frequency hopping data with frequency hopping interference .

Sign in / Sign up

Export Citation Format

Share Document