scholarly journals Characterization of Lignin Structures in Phyllostachys edulis (Moso Bamboo) at Different Ages

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 187 ◽  
Author(s):  
Yikui Zhu ◽  
Jiawei Huang ◽  
Kaili Wang ◽  
Bo Wang ◽  
Shaolong Sun ◽  
...  
Keyword(s):  
Lignin Content ◽  
First Year ◽  
Phyllostachys Edulis ◽  
Bamboo Culm ◽  
Structure Estimation ◽  
Gramineous Plant ◽  
Different Ages ◽  
Ft Ir ◽  
G Ratio

Bamboo is a gramineous plant widely distributed in China and has great prospects. Normally, local people cut bamboo culm at first year for paper milling or at six years for construction. Understanding lignin changes in bamboo with aging is necessary for better exploring the application of bamboo at different ages and can also promote the application of bamboo more effectively. Based on the previous study, the chemical structure and the lignin content of bamboo at different ages were further explored by FT-IR, GPC, NMR and other chemical methods in this paper. Results showed that the lignin structures of bamboo at different ages were similar with three monomers of S, G and H, but the molecular weight increased with age. Quantitative structure estimation further confirmed that S-type lignin content and S/G ratio of bamboo lignin constantly increased with age.

scholarly journals Production of Alginate from Persian Gulf Sargassum angustifolium Seaweeds: Novel Extraction and Characterization Methods

2021 ◽  
Vol In Press (In Press) ◽  
Author(s):  
Abdolazim Behfar ◽  
Narges Aqajari ◽  
Mohammad Reza Shushizadeh ◽  
Zahra Ramezani ◽  
Ebrahim Rajabzadeh Ghatrami
Keyword(s):  
Biological Activities ◽  
Hydroxyl Groups ◽  
Characterization Methods ◽  
Mixture Treatment ◽  
Wide Range ◽  
Ft Ir ◽  
Sargassum Angustifolium ◽  
The Fourier Transform ◽  
G Ratio

Background: Brown seaweeds contain polysaccharides, minerals, proteins, pigments, polyphenols, and fatty acids. Several of these compounds show a wide range of biological activities, such as anticoagulant, anti-tumor, antiviral, and anti-cancer effects. Objectives: This study was designed to evaluate the extraction, purification, and characterization of alginate from Sargassum angustifolium simultaneous with fucoidan extraction and the effect of this process on the structure and properties of alginate. Methods: The extraction of alginate from S. angustifolium was carried out using defatting with organic solvents mixture, treatment with acid-base solutions, and purification with absolute ethanol. The novel characterization of this compound was carried out by the Fourier transform infrared spectroscopy (FT-IR), FT-NMR, energy dispersive X-ray (EDX), and florescent spectrophotometry methods. Results: The fluorescent emission of alginate showed 66.54% removal of impurities, such as phenolic compounds. The FT-IR analysis showed the carboxyl and hydroxyl groups as significant signals in the alginate structure. By analyzing the anomeric protons and other aspects of 1H-NMR, M/G ratio, FG, FM, FGG, FMM, FMG (or FGM) were determined to be 0.61, 0.62, 0.38, 0.31, 0.07, and 0.31, respectively. The intrinsic viscosity and molecular weight of alginate were 0.9 dL/g and 41.53 kDa, respectively. Conclusions: The total amount of alginate from the residual S. angustifolium was 17% of dried seaweed. The structure elucidation of alginate was performed with the FT-IR, FT-NMR, and EDX methods.

Characterization of hemicelluloses in Phyllostachys edulis (moso bamboo) culm during xylogenesis

2019 ◽  
Vol 221 ◽  
pp. 127-136 ◽  
Author(s):  
Kai-li Wang ◽  
Bo Wang ◽  
Ruibo Hu ◽  
Xianhai Zhao ◽  
Huiling Li ◽  
...  
Keyword(s):  
Moso Bamboo ◽  
Phyllostachys Edulis ◽  
Bamboo Culm

Characterization of Apatite from Human Teeth via XRD, FT-IR and TGA Techniques

2012 ◽  
Vol 506 ◽  
pp. 90-93 ◽  
Author(s):  
Piyapong Pankaew ◽  
Ekachai Hoonnivathana ◽  
Supphadate Sujinnapram ◽  
Kheamrutai Thamaphat ◽  
Pichet Limsuwan ◽  
...  
Keyword(s):  
Chemical Structure ◽  
Nanocrystalline Structure ◽  
X Ray Diffraction ◽  
Human Teeth ◽  
Carbonated Apatite ◽  
Different Ages ◽  
Natural Composites ◽  
Ft Ir ◽  
And Function

Human teeth (HT) are natural composites which consist of nanohydroxyapatite (HAp) arranged in lamellae and bound to collagen. In present study, prepared HT powders with different ages were characterized by X-Ray Diffraction (XRD), Fourier transform infrared (FT-IR) and thermogravimetric anlysis (TGA) techniques. HT at age ranges of 1-10, 11-20, 21-30, 31-40, 41-50 and 51-60 years old were selected for tests. To prepare samples, human teeth were washed in boiling water for 1 h and left in 1 M KOH solution for 6 h to remove any organic material. After HT samples were cleaned with ultrasonic in ethanol, they were then finely grounded using agate mortar. The results from XRD indicate that the major diffraction peaks of all samples with different ages were very closely identified to that of stoichiometric HAp. All HT powders were found to be nanocrystalline structure. Furthermore, it was found that the decrease in HAp crystallinity seem to increase with higher age of 31-40 years old. To investigate chemical structure confirmed by FT-IR, All HT powders showed the band positions and function groups, which are similar to that of HAp. group found in chemical structure indicates the structure of carbonated apatite. TGA results were found that the increase of weight loss seem to increase with higher age.

Spectral Investigation on the Growth and Characterization of NLO Crystals of Thiourea Succinic Acid Single Crystal.

2015 ◽  
Vol 2 (2) ◽  
pp. 70-73
Author(s):  
Kannan.P ◽  
Thambidurai.S ◽  
Suresh.N
Keyword(s):  
Single Crystal ◽  
Succinic Acid ◽  
Slow Evaporation Technique ◽  
Absorption Studies ◽  
Dta Analysis ◽  
Evaporation Technique ◽  
Ft Ir ◽  
Ir Spectroscopic ◽  
Thermal Stability Of

Growth of optically transparent single crystals of thiourea succinic acid (TUSA) was grown successfully from aqueous solution by slow evaporation technique. The crystal structure was elucidated using the single crystal XRD. The various functional groups and the modes of vibrations were identified by FT-IR spectroscopic analysis. The optical absorption studies indicate that the optical transparency window is quite wide making its suitable for NLO applications. Thermal stability of the crown crystal carried out by TGA-DTA analysis.

Thermal Behaviour of Candesartan Active substance and in pharmaceutical compounds

2017 ◽  
Vol 68 (8) ◽  
pp. 1895-1902
Author(s):  
Ioana Cristina Tita ◽  
Eleonora Marian ◽  
Bogdan Tita ◽  
Claudia Crina Toma ◽  
Laura Vicas
Keyword(s):  
Thermal Behaviour ◽  
Active Substance ◽  
Pharmaceutical Research ◽  
Pharmaceutical Product ◽  
Nitrogen Atmosphere ◽  
Pure Substance ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Ft Ir

Thermal analysis is one of the most frequently used instrumental techniques in the pharmaceutical research, for the thermal characterization of different materials from solids to semi-solids, which are of pharmaceutical relevance. In this paper, simultaneous thermogravimetry/derivative thermogravimetry (TG/DTG) and differential scanning calorimetry (DSC) were used for characterization of the thermal behaviour of candesartan cilexetil � active substance (C-AS) under dynamic nitrogen atmosphere and nonisothermal conditions, in comparison with pharmaceutical product containing the corresponding active substance. It was observed that the commercial samples showed a different thermal profile than the standard sample, caused by the presence of excipients in the pharmaceutical product and to possible interaction of these with the active substance. The Fourier transformed infrared spectroscopy (FT-IR) and X-ray powder diffraction (XRPD) were used as complementary techniques adequately implement and assist in interpretation of the thermal results. The main conclusion of this comparative study was that the TG/DTG and DSC curves, together with the FT-IR spectra, respectively X-ray difractograms constitute believe data for the discrimination between the pure substance and pharmaceutical forms.

Preparation and Characterization of Soybean Oil-based Flame Retardant Rigid Polyurethane Foams Containing Phosphaphenanthrene Groups

2020 ◽  
Vol 17 (10) ◽  
pp. 760-771
Author(s):  
Qirui Gong ◽  
Niangui Wang ◽  
Kaibo Zhang ◽  
Shizhao Huang ◽  
Yuhan Wang
Keyword(s):  
Soybean Oil ◽  
Flame Retardant ◽  
Chemical Structure ◽  
Cell Structure ◽  
Polyurethane Foams ◽  
Limiting Oxygen Index ◽  
Rigid Polyurethane Foams ◽  
Degradation Activation Energy ◽  
Ft Ir

A phosphaphenanthrene groups containing soybean oil based polyol (DSBP) was synthesized by epoxidized soybean oil (ESO) and 9,10-dihydro-oxa-10-phosphaphenanthrene-10-oxide (DOPO). Soybean oil based polyol (HSBP) was synthesized by ESO and H2O. The chemical structure of DSBP and HSBP were characterized with FT-IR and 1H NMR. The corresponding rigid polyurethane foams (RPUFs) were prepared by mixing DSBP with HSBP. The results revealed apparent density and compression strength of RPUFs decreased with increasing the DSBP content. The cell structure of RPUFs was examined by scanning electron microscope (SEM) which displayed the cells as spherical or polyhedral. The thermal degradation and flame retardancy of RPUFs were investigated by thermogravimetric analysis, limiting oxygen index (LOI), and UL 94 vertical burning test. The degradation activation energy (Ea) of first degradation stage reduced from 80.05 kJ/mol to 37.84 kJ/mol with 80 wt% DSBP. The RUPF with 80 wt% DSBP achieved UL94 V-0 rating and LOI 28.3. The results showed that the flame retardant effect was mainly in both gas phase and condensed phase.

Isolasi Dan Karakterisasi Bentonit Alam Menjadi Nanopartikel Monmorillonit

2018 ◽  
Vol 3 (1) ◽  
pp. 12 ◽  
Author(s):  
Zaimahwati Zaimahwati ◽  
Yuniati Yuniati ◽  
Ramzi Jalal ◽  
Syahman Zhafiri ◽  
Yuli Yetri
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Particle Size ◽  
Surface Morphology ◽  
Average Diameter ◽  
Particle Size Analyzer ◽  
Ft Ir ◽  
Scanning Electron ◽  
Sedimentation Processes

<p>Pada penelitian ini telah dilakukan isolasi dan karakterisasi bentonit alam menjadi nanopartikel montmorillonit. Bentonit alam yang digunakan diambil dari desa Blangdalam, Kecamatan Nisam Kabupaten Aceh Utara.  Proses isolasi meliputi proses pelarutan dengan aquades, ultrasonic dan proses sedimentasi. Untuk mengetahui karakterisasi montmorillonit dilakukan uji FT-IR, X-RD dan uji morfologi permukaan dengan Scanning Electron Microscopy (SEM). Partikel size analyzer untuk menganalisis dan menentukan ukuran nanopartikel dari isolasi bentonit alam. Dari hasil penelitian didapat ukuran nanopartikel montmorillonit hasil isolasi dari bentonit alam diperoleh berdiameter rata-rata 82,15 nm.</p><p><em>In this research we have isolated and characterized natural bentonite into montmorillonite nanoparticles. Natural bentonite used was taken from Blangdalam village, Nisam sub-district, North Aceh district. The isolation process includes dissolving process with aquades, ultrasonic and sedimentation processes.  The characterization of montmorillonite, FT-IR, X-RD and surface morphology test by Scanning Electron Microscopy (SEM). Particle size analyzer to analyze and determine the size of nanoparticles from natural bentonite insulation. From the research results obtained the size of montmorillonite nanoparticles isolated from natural bentonite obtained an average diameter of 82.15 nm.</em></p>

scholarly journals Fabrication and Characterization of Electrospun Poly(acrylonitrile-co-Methyl Acrylate)/Lignin Nanofibers: Effects of Lignin Type and Total Polymer Concentration

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 992
Author(s):  
Suchitha Devadas ◽  
Saja M. Nabat Al-Ajrash ◽  
Donald A. Klosterman ◽  
Kenya M. Crosson ◽  
Garry S. Crosson ◽  
...  
Keyword(s):  
Methyl Acrylate ◽  
Lignin Content ◽  
Polymer Concentration ◽  
Weight Ratio ◽  
Electrospun Nanofibers ◽  
Polymer Content ◽  
Blend Ratio ◽  
Blend Ratios ◽  
Poly Acrylonitrile

Lignin macromolecules are potential precursor materials for producing electrospun nanofibers for composite applications. However, little is known about the effect of lignin type and blend ratios with synthetic polymers. This study analyzed blends of poly(acrylonitrile-co-methyl acrylate) (PAN-MA) with two types of commercially available lignin, low sulfonate (LSL) and alkali, kraft lignin (AL), in DMF solvent. The electrospinning and polymer blend solution conditions were optimized to produce thermally stable, smooth lignin-based nanofibers with total polymer content of up to 20 wt % in solution and a 50/50 blend weight ratio. Microscopy studies revealed that AL blends possess good solubility, miscibility, and dispersibility compared to LSL blends. Despite the lignin content or type, rheological studies demonstrated that PAN-MA concentration in solution dictated the blend’s viscosity. Smooth electrospun nanofibers were fabricated using AL depending upon the total polymer content and blend ratio. AL’s addition to PAN-MA did not affect the glass transition or degradation temperatures of the nanofibers compared to neat PAN-MA. We confirmed the presence of each lignin type within PAN-MA nanofibers through infrared spectroscopy. PAN-MA/AL nanofibers possessed similar morphological and thermal properties as PAN-MA; thus, these lignin-based nanofibers can replace PAN in future applications, including production of carbon fibers and supercapacitors.

scholarly journals Synthesis, Fabrication, and Characterization of Functionalized Polydiacetylene Containing Cellulose Nanofibrous Composites for Colorimetric Sensing of Organophosphate Compounds

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1869
Author(s):  
A K M Mashud Alam ◽  
Donovan Jenks ◽  
George A. Kraus ◽  
Chunhui Xiang
Keyword(s):  
Solid State ◽  
Hydroxyl Groups ◽  
Colorimetric Sensing ◽  
Electrospinning Technique ◽  
Hazardous Chemical ◽  
Tensile Tester ◽  
Vis Spectroscopy ◽  
Ft Ir ◽  
Landmark Study

Organophosphate (OP) compounds, a family of highly hazardous chemical compounds included in nerve agents and pesticides, have been linked to more than 250,000 annual deaths connected to various chronic diseases. However, a solid-state sensing system that is able to be integrated into a clothing system is rare in the literature. This study aims to develop a nanofiber-based solid-state polymeric material as a soft sensor to detect OP compounds present in the environment. Esters of polydiacetylene were synthesized and incorporated into a cellulose acetate nanocomposite fibrous assembly developed with an electrospinning technique, which was then hydrolyzed to generate more hydroxyl groups for OP binding. Scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), Instron® tensile tester, contact angle analyzer, and UV–Vis spectroscopy were employed for characterizations. Upon hydrolysis, polydiacetylene esters in the cellulosic fiber matrix were found unaffected by hydrolysis treatment, which made the composites suitable for OP sensing. Furthermore, the nanofibrous (NF) composites exhibited tensile properties suitable to be used as a textile material. Finally, the NF composites exhibited colorimetric sensing of OP, which is visible to the naked eye. This research is a landmark study toward the development of OP sensing in a protective clothing system.

Sign in / Sign up

Export Citation Format

Share Document