scholarly journals Fractionation of lignin produced from the Earleaf Acacia tree by sequential industrial organic solvents

2021 ◽  
Vol 24 (1) ◽  
pp. 1835-1841
Author(s):  
Thong Hoang Le ◽  
Khanh B. Vu ◽  
Quynh-Thy Song Nguyen ◽  
Phat Van Huynh ◽  
Khanh-Ly T. Huynh ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Organic Solvent ◽  
Ethyl Acetate ◽  
Organic Solvents ◽  
Weight Fraction ◽  
Ft Ir ◽  
Catalytic Applications ◽  
Light Medium ◽  
Acacia Tree ◽  
Different Molecular Weight

Introduction: Understanding the fractions of lignin is important for further conversion of lignin into valuable products. Herein, the “home-made” lignin from Earleaf Acacia tree was extracted by sequential industrial organic solvent and characterized each fraction to reveal its properties for further catalytic applications. Methods: In this work, lignin was prepared from the Earleaf Acacia tree using the soda method. Then, the prepared lignin was fractionated by sequential solvents of ethyl acetate, ethanol, methanol, and acetone. Each lignin fractions were characterized by FT-IR and GPC. Results: The FT-IR results confirmed the soda method can produce lignin from woodchips. The fractionation of lignin separated the lignin mixture into different molecular weight fraction from light – medium into heavy compounds. Conclusion: Lignin was produced from woodchips using the soda method successfully. The fractionation using the sequential organic solvents showed the separation of different molecular weight of lignin, which allow to apply for the further conversion into useful products.

scholarly journals Insight to Microbial Fe(III) Reduction Mediated by Redox-Active Humic Acids with Varied Redox Potentials

2021 ◽  
Vol 18 (13) ◽  
pp. 6807
Author(s):  
Jingtao Duan ◽  
Zhiyuan Xu ◽  
Zhen Yang ◽  
Jie Jiang
Keyword(s):  
Molecular Weight ◽  
Electron Transfer ◽  
Humic Acids ◽  
Weight Fraction ◽  
Electrochemical Analysis ◽  
Microbial Reduction ◽  
Redox Potentials ◽  
Groundwater Environment ◽  
Redox Active ◽  
Different Molecular Weight

Redox-active humic acids (HA) are ubiquitous in terrestrial and aquatic systems and are involved in numerous electron transfer reactions affecting biogeochemical processes and fates of pollutants in soil environments. Redox-active contaminants are trapped in soil micropores (<2 nm) that have limited access to microbes and HA. Therefore, the contaminants whose molecular structure and properties are not damaged accumulate in the soil micropores and become potential pollution sources. Electron transfer capacities (ETC) of HA reflecting redox activities of low molecular weight fraction (LMWF, <2.5) HA can be detected by an electrochemical method, which is related to redox potentials (Eh) in soil and aquatic environments. Nevertheless, electron accepting capacities (EAC) and electron donating capacities (EDC) of these LMWF HA at different Eh are still unknown. EDC and EAC of different molecular weight HA at different Eh were analyzed using electrochemical methods. EAC of LMWF at −0.59 V was 12 times higher than that at −0.49 V, while EAC increased to 2.6 times when the Eh decreased from −0.59 V to −0.69 V. Afterward, LMWF can act as a shuttle to stimulate microbial Fe(III) reduction processes in microbial reduction experiments. Additionally, EAC by electrochemical analysis at a range of −0.49–−0.59 V was comparable to total calculated ETC of different molecular weight fractions of HA by microbial reduction. Therefore, it is indicated that redox-active functional groups that can be reduced at Eh range of −0.49–−0.59 are available to microbial reduction. This finding contributes to a novel perspective in the protection and remediation of the groundwater environment in the biogeochemistry process.

scholarly journals Diverse resourcing of Nerium indicum leaves for bio-utilization

2020 ◽  
Vol 24 (3 Part A) ◽  
pp. 1785-1793
Author(s):  
Dongli Ma ◽  
Yuanyuan Chen ◽  
Yong Lai ◽  
Zanpei Zhang ◽  
Ximei Li ◽  
...  
Keyword(s):  
Organic Solvent ◽  
Organic Solvents ◽  
Raw Materials ◽  
Chemical Constituents ◽  
Food Additives ◽  
Ornamental Plant ◽  
Bioactive Ingredients ◽  
Ft Ir ◽  
Medicinal Properties ◽  
Alcohol Benzene

Nerium indicum is an ornamental plant that is widely distributed in tropical and subtropical regions wordwide. It has toxic and medicinal properties which is closely related to the bioactive ingredients contained in Nerium indicum. In our research, the leaves of Nerium indicum was used as raw materials to study the chemical constituents and their effects. The chemical constituents of the leaves were analyzed by FT-IR and GC-MS with alcohol, benzene and acetone as organic solvents. A total of 73 compounds were obtained by acetone organic solvent, 25 compounds were extracted from benzene and 146 compounds were obtained from alcohol. Rich bioactive and bioenergy components were found in all three kinds of extract, suggesting that Nerium indicum leaves are of great significance for the diverse resourcing of bio-utilization including biomedicine, bioenergy, aroma, food additives.

scholarly journals Selected Radical Azoinitiators in the synthesis of Solvent-Borne Acrylic Pressure-Sensitive Adhesives

2009 ◽  
Vol 3 (2) ◽  
pp. 101-106
Author(s):  
Barbara Pabin-Szafko ◽  
◽  
Ewa Wisniewska ◽  
Zbigniew Czech ◽  
◽  
...  
Keyword(s):  
Molecular Weight ◽  
Acrylic Acid ◽  
Organic Solvent ◽  
Ethyl Acetate ◽  
Radical Polymerization ◽  
Methyl Acrylate ◽  
Pressure Sensitive Adhesives ◽  
Pressure Sensitive

Functional azoinitiators: 2,2’-azobis(2-methyl-4-hydroxybutyl propionate) (AIB-BD), 2,2’-azobis[2-methyl-ω-hydroxy-tri(oxyethylene) propionate] [AIB-Tri(OE)] and 2,2’-azobis[2-methyl-ω-hydroxy-oligo(oxyethylene) propionate] [AIB-OOE(400)] were used in radical polymerization of 2-ethylhexyl acrylate, methyl acrylate and acrylic acid in organic solvent ethyl acetate to prepare solvent-borne acrylic pressure-sensitive adhesives (PSA). After polymerization the viscosity, molecular weight and polydispersity of received acrylic PSA have been evaluated and compared with the product of polymerization initiated by the conventional azoinitiator 2,2’-azobisisobutyronitrile (AIBN).

scholarly journals Crosslinked Carbon Nano Dots Membranes for Organic Solvent Nanofiltration

2021 ◽  
Author(s):  
Mahsa Abbaszadeh ◽  
Andrew Atkinson ◽  
Kevin Trinh ◽  
Santanu Kundu
Keyword(s):  
Molecular Weight ◽  
Organic Solvent ◽  
Organic Solvents ◽  
Active Layer ◽  
Uv Light ◽  
Layer By Layer ◽  
Facile Synthesis ◽  
Long Duration ◽  
Synthesis Strategy ◽  
Organic Solvent Nanofiltration

We report a facile synthesis strategy of a membrane active layer consisting of crosslinked carbon nano dots through a layer-by-layer process and the application of these membranes in organic solvent nanofiltration. The synthesized membrane is stable in organic solvents for a long duration, displays tight molecular weight cut off, and fluoresces under UV light, allowing one to capture mechanical failure.

The Causative Agent in Atrial Receptor Diuresis in the dog is a Low Molecular Weight, Lipophilic and Weakly Acidic Substance

1985 ◽  
Vol 68 (2) ◽  
pp. 243-246 ◽  
Author(s):  
J. M. Pither ◽  
M. F. Knapp ◽  
H. Gregory ◽  
R. J. Linden
Keyword(s):  
Molecular Weight ◽  
Ethyl Acetate ◽  
Left Atrium ◽  
Antidiuretic Hormone ◽  
Aqueous Phase ◽  
Weight Fraction ◽  
Low Molecular Weight ◽  
Humoral Agent ◽  
Atrial Receptors ◽  
Stimulation Of

1. Stimulation of atrial receptors by distension of a balloon in the left atrium of anaesthetized dogs results in a reflex diuresis mediated by a humoral agent of unknown identity. 2. In previous investigations, a substance was recovered in a low molecular weight fraction from Bio-Gel P-2 (100-1800 daltons) and shown to be related to the reflex diuresis. 3. In this investigation, the active Bio-Gel P-2 fraction was partitioned with ethyl acetate at pH 11.0, with subsequent partition of the aqueous phase with ethyl acetate at pH 7.4; the activity of the humoral agent was soluble in ethyl acetate at pH 7.4. 4. These investigations suggest that the humoral agent is a low molecular weight, lipophilic and weakly acidic substance. 5. The substance is not antidiuretic hormone (ADH) as vasopressin is insoluble in ethyl acetate at pH 7.4.

scholarly journals Molecular-mass distribution of tundra soils humic substances from the European northeast of Russia

2015 ◽  
Author(s):  
Roman Vasilevitch ◽  
Evgeniy Lodygin ◽  
Vasiliy Beznosikov
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Molecular Mass Distribution ◽  
Weight Fraction ◽  
Fulvic Acids ◽  
Low Molecular Weight ◽  
Tundra Soils ◽  
Molecular Weight Fractions ◽  
Different Molecular Weight ◽  
A Share

It is established that the humic acids (HA) of tundra soils contain three fractions with a different molecular weight: ≥600, 62–83 and 2,6–5,3 kDa; fulvic acids (FA) — one fraction — 1,5–4,4 kDa. The maintenance of a low molecular weight fraction of HA considerably exceeds a share of medium and high molecular weight fractions. Reclamation of tundra surface-gley soils leads to decrease of a share of high molecular weight and to increase of a share of low molecular weight fraction as a part of HA. Correlative dependences between the contents of HA molecular weight fractions with parameters of HA are established. Refs 16. Figs 1. Tables 3.

Synthesis, characterization and kinetics of hydrophobically associating polyacrylamide

e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Lu Hongsheng ◽  
Feng Yujun
Keyword(s):  
Molecular Weight ◽  
Particle Size ◽  
Strong Dependence ◽  
Weight Fraction ◽  
Initiator Concentration ◽  
H Nmr ◽  
Inverse Microemulsion ◽  
Ft Ir ◽  
Chain Transfer Reaction ◽  
The Difference

AbstractHAPAM was successfully prepared in inverse microemulsion. 1H-NMR, FT-IR, DSC and TG results show that the copolymerization of acrylamide (AM) with DM16 was successful. However, the ratio of AM to DM16 is not calculated exactly due to the low percentage of hydrophobic monomer in polymer. Therein, we only proved the success of the incorporation of DM16 onto polyacrylamide backbone. According to our experiment, the conversions of monomers and molecular weight have a strong dependence on initiator concentration and aqueous phase weight fraction. But it was not completely in accordance with literature. The difference may be ascribed to the major existence of locus of DM16 (at the interface of oil/water or in droplet). Compared with literature, the influence of initiator concentration on particle size was slight due to the high surfactant weight fraction, seeming to appear independent of initiator concentration. When the surfactant weight fraction reaches a certain degree, it did not affect the conversion. For the particle size and molecular weight, it was other way around, suggesting that there was an intense chain transfer reaction to the emulsifier. In this work, we could not calculate the average number of free radical per particle n, because the part of the surfactant in excess recombines to form small micelle and the DM16 may continuously transfer from micelle to another micelle, resulting in difficulty to estimate precisely the number of the particles. This was also reflected in the difference of kinetics between our system and literature. Finally, the occurrence of nucleation at high conversion was proved indirectly.

Effects of Chitosan with Different Molecular-Weight on the Properties of Cotton

2013 ◽  
Vol 821-822 ◽  
pp. 630-633
Author(s):  
Xiao Xia He ◽  
Sen Liu
Keyword(s):  
Electron Microscopy ◽  
Molecular Weight ◽  
Scanning Electron Microscopy ◽  
Cotton Fabric ◽  
Lower Molecular Weight ◽  
Dyeing Properties ◽  
Ft Ir ◽  
Different Molecular Weight ◽  
Scanning Electron

The structure and dyeing properties of the untreated, oxidized, chitosan treated cotton fabric were studied. Due to the deposition of chitosan particles, the cotton surface appeare to be uneven in comparison with that of untreated one as seen from the scanning electron microscopy (SEM); the FT-IR indicate the physical attachment of chitosan to the cotton fabric; high dye exhaustion and color yields (K/S) could be achieved on the chitosan treated cotton than that on the untreated one; with higher molecular-weight of the chitosan, the dyeability mentioned above are superior to that with lower molecular-weight.

scholarly journals Crosslinked Carbon Nano Dots Membranes for Organic Solvent Nanofiltration

2021 ◽  
Author(s):  
Mahsa Abbaszadeh ◽  
Andrew Atkinson ◽  
Kevin Trinh ◽  
Santanu Kundu
Keyword(s):  
Molecular Weight ◽  
Organic Solvent ◽  
Organic Solvents ◽  
Active Layer ◽  
Uv Light ◽  
Layer By Layer ◽  
Facile Synthesis ◽  
Long Duration ◽  
Synthesis Strategy ◽  
Organic Solvent Nanofiltration

We report a facile synthesis strategy of a membrane active layer consisting of crosslinked carbon nano dots through a layer-by-layer process and the application of these membranes in organic solvent nanofiltration. The synthesized membrane is stable in organic solvents for a long duration, displays tight molecular weight cut off, and fluoresces under UV light, allowing one to capture mechanical failure.

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