scholarly journals Valorization of Byproducts of Hemp Multipurpose Crop: Short Non-Aligned Bast Fibers as a Source of Nanocellulose

Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4723
Author(s):  
Sara Dalle Vacche ◽  
Vijayaletchumy Karunakaran ◽  
Alessia Patrucco ◽  
Marina Zoccola ◽  
Loreleï Douard ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Thermogravimetric Analysis ◽  
Cannabis Sativa ◽  
Crystallinity Index ◽  
Residual Lignin ◽  
Chemical Pretreatment ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bast Fibers ◽  
Seed Maturity

Nanocellulose was extracted from short bast fibers, from hemp (Cannabis sativa L.) plants harvested at seed maturity, non-retted, and mechanically decorticated in a defibering apparatus, giving non-aligned fibers. A chemical pretreatment with NaOH and HCl allowed the removal of most of the non-cellulosic components of the fibers. No bleaching was performed. The chemically pretreated fibers were then refined in a beater and treated with a cellulase enzyme, followed by mechanical defibrillation in an ultrafine friction grinder. The fibers were characterized by microscopy, infrared spectroscopy, thermogravimetric analysis and X-ray diffraction after each step of the process to understand the evolution of their morphology and composition. The obtained nanocellulose suspension was composed of short nanofibrils with widths of 5–12 nm, stacks of nanofibrils with widths of 20–200 nm, and some larger fibers. The crystallinity index was found to increase from 74% for the raw fibers to 80% for the nanocellulose. The nanocellulose retained a yellowish color, indicating the presence of some residual lignin. The properties of the nanopaper prepared with the hemp nanocellulose were similar to those of nanopapers prepared with wood pulp-derived rod-like nanofibrils.

scholarly journals Coordination Assemblies of Zn(II) Coordination Polymers: Positional Isomeric Effect and Optical Properties

Crystals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 664 ◽  
Author(s):  
Chang-Jie Liu ◽  
Tong-Tong Zhang ◽  
Wei-Dong Li ◽  
Yuan-Yuan Wang ◽  
Shui-Sheng Chen
Keyword(s):  
Optical Properties ◽  
Infrared Spectroscopy ◽  
Thermogravimetric Analysis ◽  
Quantum Yield ◽  
Coordination Polymers ◽  
Square Lattice ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mixed Ligands ◽  
Isomeric Effect

Two Zn(II) coordination polymers (CPs) [Zn(L)(pphda)] (1) and [Zn(L)(ophda)]·H2O (2) were prepared by reactions of ZnSO4·7H2O based on the N-donor 1,4-di(1H-imidazol-4-yl)benzene (L) ligand and two flexible carboxylic acids isomers of 1,4-phenylenediacetic acid (H2pphda) and 1,2-phenylenediacetic acid (H2ophda) as mixed ligands, respectively. Structures of CPs 1 and 2 were characterized by elemental analysis, Infrared spectroscopy (IR), thermogravimetric analysis and single-crystal X-ray diffraction. The CP 1 is a fourfold interpenetrating 66-diamond (dia) architecture, while 2 is a 2D (4, 4) square lattice (sql) layer based on the Zn2(cis-1,2-ophda2−)2 binuclear Zn(II) subunits. The luminescent property, including luminescence lifetime and quantum yield (QY), have been investigated for CPs 1 and 2.

Synthesis and Characterization of Polyaniline Copolymer

2012 ◽  
Vol 217-219 ◽  
pp. 551-554
Author(s):  
Ting Xi Li ◽  
Yu Hua Zhao ◽  
Qian Li ◽  
Cheng Qian Yuan ◽  
Quan Liang Chen ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Infrared Spectroscopy ◽  
Thermogravimetric Analysis ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir ◽  
The Difference ◽  
Thermal Stability Of

Abstract. Polyaniline (PANI) and p-phenylenediamine (p-PDA)-aniline copolymer were prepared via a same microemulsion method. The structures of the PANI and p-PDA-aniline copolymer were characterized by infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis（TGA）. The results revealed the difference of synthesis and characterization between PANI and p-PDA-aniline copolymer. It was shown that structure of the copolymer is almost similar to that of PANI, but the p-PDA-aniline copolymer has a better crystallization than PANI, and the thermal stability of the copolymer is higher than that of pure PANI.

scholarly journals Exploiting a new europium(III) coordination polymer based on a zwitterionic ligand as a fluorescent probe for uranyl cations

2020 ◽  
pp. 174751982093226
Author(s):  
Bin Cai ◽  
Yu-Ning Meng ◽  
Meng-En Zhu ◽  
Youming Yang
Keyword(s):  
Infrared Spectroscopy ◽  
Thermogravimetric Analysis ◽  
Coordination Polymer ◽  
High Selectivity ◽  
Limit Of Detection ◽  
High Sensitivity ◽  
Fast Response ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
X Ray

Two new isostructural lanthanide(III) coordination polymers based on an unreported zwitterionic ligand, namely, [Ln(ox)(L)]n (ox = oxalate, HL = N,N'-dipropionic acid imidazolium, Ln = Eu or La), are synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction, infrared spectroscopy, powder X-ray diffraction, and thermogravimetric analysis. The fluorescence properties of the europium coordination polymer are investigated. In addition, the europium-based coordination polymer is utilized for specific sensing of UO22+ ions, showing high selectivity, a fast response time (8 min) and high sensitivity with noticeable quenching ( Ksv = 6.19 × 104 M−1) and limit of detection of 1.95 µM.

Synthesis and Characterization of Novel Organomodified Nanoclays for Application in Dental Materials

2019 ◽  
Vol >15 (5) ◽  
pp. 512-524 ◽  
Author(s):  
Alexandros K. Nikolaidis ◽  
Elisabeth A. Koulaouzidou ◽  
Dimitris S. Achilias
Keyword(s):  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Thermogravimetric Analysis ◽  
Fourier Transform Infrared Spectroscopy ◽  
Quaternary Ammonium ◽  
Fourier Transform Infrared ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
X Ray

Background: Nanoclays incorporated in dental resins have been previously investigated. However, limited reports are associated with nanoclays that exhibit high functionality. Objective: The aim of this study was the targeted synthesis and characterization of organomodified nanoclays with methacrylic groups suitable for incorporation in dental nanocomposite resins. Methods: Quaternary ammonium methacrylates were synthesized and characterized by means of proton nuclear magnetic resonance and Fourier-transform infrared spectroscopy. Consequently, they were inserted into the interlayer space of nanoclay through a cation exchange reaction, while silane was also used for simultaneous surface modification. The produced organomodified nanoclays were characterized by means of X-ray diffraction, Fourier-transform infrared spectroscopy and thermogravimetric analysis. Results: Fourier-transform infrared spectra confirmed the successful synthesis of the quaternary ammonium methacrylates. X-ray diffraction analysis showed that organoclays exhibited higher d001- values (up to 1.78 nm) compared to raw nanoclay (1.37 nm), indicating an accomplished intercalation in each case. X-ray diffraction spectra mainly disclosed the presence of methacrylic functional groups in all nanoclays. Thermogravimetric analysis curves verified the different thermal stability of organoclays due to the diversity of their organic modifiers. Conclusion: The experimental results showed that nanoclay was successfully modified with ammonium methacrylates and silane. Τhe combination of X-ray diffraction and thermogravimetric analysis data revealed a high degree of intercalation and methacrylated organic loading as well. These phenomena may favor a good dispersion and high polymerization degree of nanoclays with dental resin monomers, rendering them potentially useful materials for the development of advanced dental nanocomposites resins.

scholarly journals Alcohol Oxidation Assisted by Molybdenum Hydrazonato Catalysts Employing Hydroperoxide Oxidants

Catalysts ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 881
Author(s):  
Josipa Mihalinec ◽  
Matea Pajski ◽  
Pascal Guillo ◽  
Mirna Mandarić ◽  
Nikol Bebić ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Infrared Spectroscopy ◽  
Thermogravimetric Analysis ◽  
Magnetic Resonance ◽  
Alcohol Oxidation ◽  
Polynuclear Complexes ◽  
Oxidation Reactions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mononuclear Complexes

Molybdenum(VI) catalysts were obtained from methanol or acetonitrile by the reaction of [MoO2(C5H7O2)2] and isonicotinoyl- or nicotinoyl-based aroylhydrazones. Reactions in methanol resulted in the formation of the mononuclear complexes [MoO2(L1–4)(MeOH)] (1a–4a), while the ones in acetonitrile provided polynuclear complexes [MoO2(L1–4)]n (1–4). Crystals of polynuclear compound, [MoO2(L3)]n∙H2O (3∙H2O), suitable for X-ray diffraction analysis were obtained by the solvothermal procedure at 110 °C. Complexes were characterized by infrared spectroscopy (IR-ATR), nuclear magnetic resonance (NMR), elemental analysis (EA), and thermogravimetric analysis (TGA). The prepared catalysts were tested in alcohol oxidation reactions. Carveol, cyclohexanol, and butan-2-ol were investigated substrates. Because the alcohol oxidations are very challenging due to various possible pathways, the idea was to test different oxidants, H2O2, TBHP in water and decane, to optimize the researched catalytic system.

Syntheses, structural diversity, and photocatalytic-degradation properties for methylene blue of Co(ii) and Ni(ii) MOFs based on terephthalic acid and different imidazole bridging ligands

CrystEngComm ◽  
2019 ◽  
Vol 21 (25) ◽  
pp. 3798-3809 ◽  
Author(s):  
Lian-sheng Cui ◽  
Xiang-min Meng ◽  
Yong-gang Li ◽  
Ke-rui Huang ◽  
Yuan-cheng Li ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Infrared Spectroscopy ◽  
Thermogravimetric Analysis ◽  
Terephthalic Acid ◽  
Structural Diversity ◽  
X Ray Diffraction ◽  
Bridging Ligands ◽  
X Ray ◽  
Elemental Analyses ◽  
Degradation Properties

Six coordination polymers were constructed and characterized by X-ray diffraction, elemental analyses, infrared spectroscopy and thermogravimetric analysis.

Characterization of modified iron catalysts by X-ray diffraction, infrared spectroscopy, magnetic susceptibility and thermogravimetric analysis

2004 ◽  
Vol 58 (20) ◽  
pp. 2447-2450 ◽  
Author(s):  
Serbia M Rodulfo-Baechler ◽  
Sergio L González-Cortés ◽  
José Orozco ◽  
Vicente Sagredo ◽  
Bernardo Fontal ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
Infrared Spectroscopy ◽  
Thermogravimetric Analysis ◽  
Iron Catalysts ◽  
X Ray Diffraction ◽  
X Ray

Preparation of PVA/ Sm(NO3)3-Sm2O3 Composites Nanofibers by Electrospinning Technique

2010 ◽  
Vol 71 ◽  
pp. 22-27 ◽  
Author(s):  
Patrizia Frontera ◽  
Concetta Busacca ◽  
Vincenza Modafferi ◽  
Pierluigi Antonucci ◽  
Massimiliano Lo Faro
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Thermogravimetric Analysis ◽  
Fourier Transform Infrared Spectroscopy ◽  
X Ray Diffraction ◽  
Electrospinning Technique ◽  
X Ray ◽  
Scanning Electron

. In this work PVA/Sm2O3 composite fibers and Sm2O3 fibers (PVA and Sm(NO3)3 were used as precursors) were prepared by using electrospinning technique. The fibers obtained were characterized by scanning electron microscopy, X-ray diffraction, thermogravimetric analysis and Fourier transform infrared spectroscopy.

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