thermal gravimetric
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Cellulose ◽  
2022 ◽  
Author(s):  
Ao Li ◽  
Dezhong Xu ◽  
Mengnan Zhang ◽  
Shengzhong Wu ◽  
Yu Li ◽  
...  

AbstractThis paper develops a novel paper additive for effectively recycling old corrugated container (OCC) by functionalizing nanocellulose (NC) with diethylenetriaminepentaacetic acid (DTPA) and chitosan (CS), and investigate the reinforcing mechanisms and effect of the developed additive on the physical properties of recycled OCC pulp handsheets. The tensile, tear and burst index, air permeability, tensile energy absorption (TEA), and drainage performance of the recycled OCC handsheets are examined. Fourier transform infrared FTIR) spectroscopy, thermal gravimetric analysis (TGA) and scanning electron microscopy (SEM) are used for the chemical and microstructure characterization of both NC based additives and paper from recycled OCC pulp. The results show that functional groups on the NC based additive, such as carboxyl, amino and hydroxyl groups, can bond with the hydroxyl groups on the recycled OCC fibres to generate a chemical bond. This leads to an increase in the crosslinks and bonding area between the fibres, which increases their tensile strength and improves their recycling rate. SEM shows that the paper with NC based additives had tighter inter-fibre bonds and smaller paper pore structure. Addition of 0.3% NC-DTPA-CS additive results in optimal properties of the recycled OCC paper with an increase by 31.64%, 22.28% and 36.6% of tensile index, tear index, burst index respectively, and the air permeability decreases by 36.92%. Graphical Abstract


2022 ◽  
Vol 58 (4) ◽  
pp. 84-93
Author(s):  
Mirela Alina Constantin ◽  
Lucian Alexandru Constantin ◽  
Sebastian Aradoaei ◽  
Mihaela Aradoaei ◽  
Mihai Bratu ◽  
...  

Sustainable materials made from recycled materials are an alternative to traditional materials (synthetic ones) and present a lower environmental impact. Due to the fact that natural fibers were successfully used to produce environmentally friendly sound adsorbing materials, biocomposites made from recycled polypropylene (PPR), feathers flour (FF) with / without compatibilizers (C) were obtained and characterized from the point of view of their acoustical behavior. Obtained materials were characterized also from the morphological and compositional point of view by scanning electron microscopy and thermal gravimetric analysis. All tested samples presented sound adsorption properties but the best results were obtained for the biocomposites with FF content of 10%-20%.


2021 ◽  
Author(s):  
Timothy Steenhaut ◽  
Séraphin Lacour ◽  
Gabriella Barozzino-Consiglio ◽  
Koen Robeyns ◽  
Robin Crits ◽  
...  

The first mesoporous bimetallic TiIII/Al metal-organic framework (MOF) containing amine functionalities on its linkers has been selectively obtained by converting the cheap commercially available (TiCl3)3AlCl3 into Ti3-xAlxCl3(THF)3 and reacting this complex with 2-aminoterephthalic acid in DMF under soft solvothermal conditions. This compound is structurally related to the previously described NH2-MIL-101(M) (M = Cr, Al and Fe) MOFs. Thermal gravimetric analyses and in situ PXRD measurements demonstrated that this highly air-sensitive TiIII-containing MOF is structurally stable up to 200°C. Nuclear magnetic resonance (NMR) spectroscopy, elemental and inductively-coupled plasma (ICP) analyses revealed that NH2-MIL-101(TiIII) contains trinuclear Ti3(μ3-O)Cl(DMF)2(RCOO)6 clusters with strongly bound DMF molecules, and a small amount of aluminum. Sorption experiments reveal a higher affinity of this MOF for hydrogen compared to the previously described monometallic unfunctionalized MIL-101(TiIII) MOF.


2021 ◽  
Vol 15 (4) ◽  
pp. 8518-8528
Author(s):  
S. Gnanasekaran ◽  
Noor Ida Amalina Ahamad Nordin ◽  
M.M.M. Hamidi ◽  
J.H. Shariffuddin

Pineapple leaves fibre (PALF) is one of the natural fibre that has high potential to substitute non-renewable synthetic fibre in thermoplastic products. The PALF were alkali treated with different concentrations of NaOH. Untreated and alkali treated PALF were characterized using Thermal Gravimetric Analysis (TGA) and Scanning Electron Microscopy (SEM) to determine the thermal stability and surface morphology of the fibres respectively. Biocomposites were prepared by reinforced alkali treated and untreated PALF with polypropylene (PP) matrix. Tensile properties and water absorption analysis of PALF/PP biocomposites were studied. Biocomposite with 8 wt.% of alkali treated PALF express excellent thermal stability, with maximum degradation temperature at 270 ℃ which is a 7.17% improvement compared to untreated PALF. This biocomposite also had increased tensile strength (116 MPa) with 43% improvement compared to untreated PALF/PP (66 MPa) biocomposite and had lower water absorption at 6% compared to untreated biocomposite which at 21%. Hence, alkali treated PALF is able to improve the characteristic of PALF and increase the compatibility between fibre and polymer by reducing hemicellulose and lignin components.


Membranes ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 972
Author(s):  
Nurul Hidayah Hussin ◽  
Roswanira Abdul Wahab ◽  
Nursyafiqah Elias ◽  
Adikwu Gowon Jacob ◽  
Mohamad Hamdi Zainal-Abidin ◽  
...  

A novel greener MNC/PES membrane was developed through an electrospinning technique for lipase immobilization to catalyze the synthesis of ethyl valerate (EV). In this study, the covalent immobilization of Aspergillus oryzae lipase (AOL) onto an electrospun nanofibrous membrane consisting of magnetic nanocellulose (MNC) and polyethersulfone (PES) to produce EV was statistically optimized. Raman spectroscopy, Fourier-transform infrared spectroscopy: attenuated total reflection, field emission scanning electron microscopy, energy dispersive X-ray spectroscopy, thermal gravimetric analysis (TGA), and differential thermal gravimetric (DTG) of MNC/PES-AOL demonstrated that AOL was successfully immobilized onto the fibers. The Taguchi design-assisted immobilization of AOL onto MNC/PES fibers identified that 1.10 mg/mL protein loading, 4 mL reaction volume, 250 rpm stirring rate, and 50 °C were optimal to yield 72.09% of EV in 24 h. The thermal stability of MNC/PES-AOL was improved by ≈20% over the free AOL, with reusability for up to five consecutive esterification cycles while demonstrating an exceptional half-life of 120 h. Briefly, the electrospun MNC/PES fibers that immobilized AOL showed promising applicability in yielding relatively good EV levels. This study suggests that using MNC as fillers in a PES to improve AOL activity and durability for a longer catalytic process could be a viable option.


Molbank ◽  
10.3390/m1287 ◽  
2021 ◽  
Vol 2021 (4) ◽  
pp. M1287
Author(s):  
Alise Kirilova ◽  
Aleksandrs Pučkins ◽  
Sergey Belyakov ◽  
Elena Kirilova

Herein, we describe the synthesis of 3-[N-(4-methoxybenzyl)amino]benzo[de]anthracen-7-one via a two-step procedure including 3-aminobenzanthrone condensation with anisaldehyde and following reduction of obtained imine to appropriate amine by sodium borohydride. The structure of the synthesized compounds was established by elemental analysis, nuclear magnetic resonance spectroscopy, mass spectrometry (EI-MS), and infrared spectroscopy (FT-IR) and confirmed by single-crystal X-ray diffraction. The title compound was analyzed by thermal gravimetric analysis, UV/vis, and fluorescence spectroscopy.


2021 ◽  
Vol 2021 ◽  
pp. 148-154
Author(s):  
G. Erkan ◽  
G.C. Türkoğlu ◽  
S.Y. Karavana ◽  
A.M. Sariişik ◽  
B. Ütebay ◽  
...  

Microencapsulation technology has been increasingly used in textile industry due to give some peculiarities such as controlled released etc. In this study we aim to make aromatherapy sportswear using lavender oil. Lavender oil is encapsulated by different wall materials. Microcapsules were obtained by spray drying method. Differential scanning calorimetry, thermal gravimetric analysis, Fourier Transform infrared spectroscopy, morphological analyses were applied to microcapsules. Optimum microcapsules were applied to different fabrics. Fastness to washing and rubbing, SEM and antibacterial tests were carried out.


Author(s):  
Oluwatoosin B. A. Agbaje ◽  
Glenn A. Brock ◽  
Zhifei Zhang ◽  
Kingsley C. Duru ◽  
Yue Liang ◽  
...  

Abstract Phosphate-shelled brachiopods differ in filter-feeding lifestyle, with Lingula anatina an active infaunal burrower, and Discinisca tenuis a shallow marine epibenthic animal. The shells of these animals are built of organophosphatic constituents, the organic fibres/sheets reinforced with calcium phosphate to provide a sophisticated ultrastructural robustness. This investigation examined the nature of the organic fibres in order to improve understanding of how living organisms produce hierarchically structured biomaterials. Unlike powdered samples commonly used in previous studies, organic fibres were isolated for the first time and the shell fractions were purified, in order to study the content and nature of the biopolymer fibres. Biochemical methods including Calcofluor staining revealed a chitin matrix. Ultrastructural analysis, thermal gravimetric analysis, and spectroscopic analyses show that the core polysaccharide framework is composed of layers of β-chitin sheets and/or fibrils that are coated with a fibrous organic matrix. There is more chitin matrix in the L. anatina shells (26.6 wt.%) compared to the D. tenuis shells (12.9 wt.%). Taken together, the data show that the chitin matrix contributes to increased skeletal strength, making L. anatina highly adapted for life as an active burrower. In comparison, D. tenuis contains less chitin and lives as attached epibenthos in a shallow marine environment. Graphical abstract First spectroscopic evidence of β-chitin sheets in recent organophosphatic brachiopods


2021 ◽  
Vol 29 (1) ◽  
pp. 73-76
Author(s):  
Ye. V. Skrypnik ◽  
M. P. Trubitsyn ◽  
A. O. Diachenko ◽  
M. D. Volnianskii

The glass of lithium-sodium tetragermanate LiNaGe4O9 is crystallized on heating under the control of differential scanning calorimetry and thermal gravimetric analysis. The measurements were prepared in the temperature range 300-870 K and showed the relatively weak endothermic DSC anomaly and 40-50 K above the single exothermic peak. The endothermic anomaly observed at Tg testified to softening the glass structure whereas the exothermic peak at TC manifested crystallization of the amorphous phase. Studying of TGA demonstrated smooth nearly linear dependences without any visible anomalies. Varying the heating rate from 1.2 up to 40 K/min resulted in noticeable increase of the characteristic temperatures Tg and TC. Lower limit of the glass transition temperature Tg0 was estimated with the help of the existing model. The mechanism of the LiNaGe4O9 glass crystallization is discussed.


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