Synthesis of aminotelechelic polymers with the redox system TiCl3NH2OH in hydrochloric aqueous phase: 3. Polymerization of methylacrylate. relation functionality/molecular weight/yield

Abstract. The fate of methacrolein in cloud evapo-condensation cycles was experimentally investigated. To this end, aqueous-phase reactions of methacrolein with OH radicals were performed (as described in Liu et al., 2009), and the obtained solutions were then nebulized and dried into a mixing chamber. ESI-MS and ESI-MS/MS analyses of the aqueous phase composition denoted the formation of high molecular weight multifunctional products containing hydroxyl, carbonyl and carboxylic acid moieties. The time profiles of these products suggest that their formation can imply radical pathways. These high molecular weight organic products are certainly responsible for the formation of secondary organic aerosol (SOA) observed during the nebulization experiments. The size, number and mass concentration of these particles increased significantly with the reaction time: after 22 h of reaction, the aerosol mass concentration was about three orders of magnitude higher than the initial aerosol quantity. The evaluated SOA yield ranged from 2 to 12%. These yields were confirmed by another estimation method based on the hygroscopic and volatility properties of the obtained SOA measured and reported by Michaud et al. (2009). These results provide, for the first time to our knowledge, strong experimental evidence that cloud processes can act, through photooxidation reactions, as important contributors to secondary organic aerosol formation in the troposphere.

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Demonstrating Aqueous-Phase Low-Molecular-Weight-Gel Wicking of Oil for the Remediation of Oil Spilled into Surface Water

Langmuir ◽

10.1021/acs.langmuir.0c00917 ◽

2020 ◽

Vol 36 (44) ◽

pp. 13155-13165

Author(s):

Daniel J. Walls ◽

Emilie Espitalié ◽

Gabriel Hum ◽

Jun Chen ◽

Michael Gattrell ◽

...

Keyword(s):

Molecular Weight ◽

Surface Water ◽

Aqueous Phase ◽

Low Molecular Weight

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Soda–AQ delignification of poplar wood. Part 1: Reaction mechanism and pulp properties

Holzforschung ◽

10.1515/hf.2008.118 ◽

2008 ◽

Vol 62 (6) ◽

Cited By ~ 8

Author(s):

Alberto D. Venica ◽

Chen-Loung Chen ◽

Josef S. Gratzl

Keyword(s):

Molecular Weight ◽

Populus Deltoides ◽

Redox System ◽

Alkali Concentration ◽

Aryl Ether ◽

Soda Pulping ◽

Flow Through ◽

Spent Liquor ◽

Wood Part ◽

Heating Up

Abstract Soda and soda-anthraquinone (AQ) pulpings of poplar (Populus deltoides) wood performed in a flow-through reactor gives rise to the formation of coniferyl alcohol (1) sinapyl alcohol (2) and other low molecular weight (LMW) compounds in different stages of delignification. During the heating-up period, the formation of these compounds increases until the maximum pulping temperature (t max, 170°C) is reached. Afterward, their concentration in the spent liquor decreases sharply. This effect is accompanied by solubilization of high molecular weight (HMW) lignin fractions. Compared with soda pulping, the soda-AQ pulping shows a higher production of LMW compounds because of the presence of AQ-anthrahydroquinone (AHQ) redox system. During the heating-up period, the formation of 1 and 2 – apparently originated from non-etherified β-aryl-ether moieties in the lignin – is accompanied by solubilization of lignin fragments with relative LMW. Lignin cores, having β-aryl-ether bonds as major hydrolyzable inter-unit linkages, remain in the fiber, and they give rise to solubilized lignin fragments with HMW at later delignification stages. The dissolved fragments, in particular those formed during heating-up period, undergo further degradation in the liquor. The degradation occurs via oligomers at the end of the pulping, while the residual lignin cores are more resistant. Pulps with low kappa number can be produced by maintaining higher alkali concentrations than the usual in the last delignification phase. When the pulping liquor is replaced in this stage with liquors of higher alkali concentration, extended delignification will be the result. As a consequence, less degraded lignin fragments will be deposited on fibers.

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Low-molecular weight components of cow colostrum regulate bone marrow functions by modelling the redox-system of the organism

Regulatory Mechanisms in Biosystems ◽

10.15421/022040 ◽

2020 ◽

Vol 11 (2) ◽

pp. 272-277

Author(s):

A. I. Bozhkov ◽

S. L. Ohiienko ◽

A. Y. Bondar ◽

E. G. Ivanov ◽

N. I. Kurguzova

Keyword(s):

Molecular Weight ◽

Bone Marrow ◽

Body Weight ◽

Large Dose ◽

Redox System ◽

Low Molecular Weight ◽

Lipid Hydroperoxides ◽

Low Doses ◽

In Vitro System

Colostrum is rich in various biologically active compounds such as immunotropic ones. Low molecular weight components were isolated from cow colostrum components (with a molecular weight of not more than 45 kDa). Their influence was investigated on intact Wistar Rattus norvegicus adult males in concentrations of 0.01, 0.1, 1.0 and 5.0 g/100 g of body weight. We determined content of lipid hydroperoxides and activity of serum glutathione peroxidase in blood serum, parameters of the bone marrow cells’ (BMCs) behaviour in the in vitro system (proliferation ability, morphologically identifiable and unidentifiable type of cells, lifespan of eosinophils). Morphological identifiable cells were stab neutrophils, segmented neutrophils, metamyelocytes, myelocytes, lymphocytes, basophils, neutrophils, eosinophils, monocytes. The low doses of colostrum components (0.01–0.10 g/100 g of body weight) did not affect the ratio of morphologically identifiable/unidentifiable cells. Administration of colostrum components at low doses (0.01 g/100 g of weight) increased the ability of BMCs to proliferate in the in vitro system. A super-large dose of colostrum components (5 g/100 g of body weight) was accompanied by a further loss of capacity for proliferation and cell death. Moreover, large doses of colostrum components resulted in change of balance to prooxidants (oxidants). The role of redox – system in BMCs functions was discussed. Large doses of colostrum components (1–5 g/100 g of body weight) were accompanied by a change of pro-antioxidant system balance. Only eosinophils were determined after administration of colostrum components in a large dose. It should be noted that the lifetime of eosinophils which developed under influence of colostrum components was greater than that of eosinophils obtained from control animals.

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USE OF MEMBRANE EMULSION SPAN 80 AND TOPO IN URANIUM EXTRACTION AND STRIPPING

Urania Jurnal Ilmiah Daur Bahan Bakar Nuklir ◽

10.17146/urania.2016.22.3.3185 ◽

2017 ◽

Vol 22 (3) ◽

Author(s):

Kris Tri Basuki ◽

Nurimaniwathy Nurimaniwathy ◽

Dian Puspita ◽

Bambang E H.B

Keyword(s):

Aqueous Phase ◽

Extraction Efficiency ◽

Influence Factors ◽

Membrane System ◽

Total Efficiency ◽

Phase 3 ◽

Uranium Extraction ◽

Span 80 ◽

Stripping Efficiency ◽

Feed Volume

USE OF MEMBRANE EMULSION SPAN 80 AND TOPO IN URANIUM EXTRACTION AND STRIPPING. Membrane emulsion span 80 and TOPO used in uranium extraction and stripping has been done. The extraction was carried outby emulsion membrane H3PO4 in TOPO-Kerosene. The feed or external aqueous phase was uranium in HNO3. The emulgator span-80 was used to obtain a stable emulsion membrane system. The influence factors were percentage of TOPO-Kerosene, time extraction, molarity of external aqueous phase and molarity of internal aqueous. After the emulsion membrane was formed, the extractionand stripping process was performed. The ratio volume feed : volume membrane phase equal to 1 : 1 and volume of 5 % TOPO-Kerosene : Volume 3 M H3PO4 equal 1 : 1 were used. The relative good yield were obtained at concentration of TOPO in Kerosene and 3 M H3PO4 was 5 %, molarity of internal aqueous phase equal to 1 M, molarity of external aqueous phase 3 M H3PO4 and time extraction equalto 10 minutes with the speed of emulsification was 8000 rpm. At this condition the extraction efficiency of uranium obtained was 97.8 %, the stripping efficiency 52.56 %, and the total efficiency was 53.80 %.Keywords: membrane emulsion, extraction, stripping, span 80, kerosene, uranium. PENGGUNAAN MEMBRAN EMULSI SPAN 80 DAN TOPO UNTUK EKSTRASI DAN STRIPPING URANIUM. Telah dilakukan penelitian membran emulsi span 80 dan TOPO yang digunakan untuk ekstraksi uranium. Extraksi dengan membran emulsi H3PO4 dalam TOPO-Kerosen. Larutan umpan untuk fasa air eksternal adalah uranium dalam asam nitrat. Untuk memperoleh sistem emulsi yang stabil dipakai emulgator Span 80. Parameter yang berpengaruh adalah persen TOPO-Kerosene, molaritas fasa air internal H3PO4, molaritas fasa air eksternal HNO3 dan waktu ekstraksi. Setelah diperoleh membran emulsi, kemudian dilakukan proses ekstraksi dan stripping, dengan rasio volume umpan : volume membran sebesar 1 : 1; volume 5% TOPO-Kerose : volume 3M H3PO4 sebesar 1 : 1. Hasil relatif lebih baik diperoleh pada konsen-trasi TOPO Kerosene: volume 3 M H3PO4 adalah 5 %, molaritas larutan fasa internal sebesar 1 M, molaritas larutan fasa eksternal adalah 3 M H3PO4 dan waktu ekstraksi sebesar 10 menit dengan kecepatan emulsi 8000 rpm. Pada kondisi ini diperoleh effisiensi ekstraksi uranium 97,8 %, efisiensi stripping 52,56 % dan efisiensi total adalah 53,8 %.Kata Kunci : membran emulsi, ekstraksi, stripping, span 80, kerosen, uranium.

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