scholarly journals An in-depth assessment into simultaneous monitoring of dissolved reactive phosphorus (DRP) and low-molecular-weight organic phosphorus (LMWOP) in aquatic environments using diffusive gradients in thin films (DGT)

2015 ◽  
Vol 17 (4) ◽  
pp. 711-727 ◽  
Author(s):  
Christian Wilhelm Mohr ◽  
Rolf David Vogt ◽  
Oddvar Røyset ◽  
Tom Andersen ◽  
Neha Amit Parekh
Keyword(s):  
Molecular Weight ◽  
Organic Phosphorus ◽  
Aquatic Environments ◽  
Low Molecular Weight ◽  
P Fractionation ◽  
Physiochemical Properties ◽  
Dissolved Reactive Phosphorus ◽  
Reactive Phosphorus ◽  
Diffusive Gradients

In situP fractionation size distribution is altered during uptake by the DGT due to the size and physiochemical properties of the molecular species.

scholarly journals Preparation of Porous Polymers by ”in Situ Precipitation” Using Low Molecular Weight Gelators

2002 ◽  
Vol 34 (6) ◽  
pp. 474-477 ◽  
Author(s):  
Masahiro Suzuki ◽  
Yasuhiko Sakakibara ◽  
Satoshi Kobayashi ◽  
Mutsumi Kimura ◽  
Hirofusa Shirai ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Porous Polymers ◽  
Low Molecular Weight ◽  
Low Molecular Weight Gelators

Instabilities in the System NMMO/Water/Cellulose (Lyocell Process) Caused by Polonowski Type Reactions

Holzforschung ◽  
2002 ◽  
Vol 56 (2) ◽  
pp. 199-208 ◽  
Author(s):  
Thomas Rosenau ◽  
Antje Potthast ◽  
Andreas Hofinger ◽  
Herbert Sixta ◽  
Paul Kosma
Keyword(s):  
Molecular Weight ◽  
Acetic Acid ◽  
Exchange Resin ◽  
Degradation Products ◽  
Ion Exchange Resin ◽  
Low Molecular Weight ◽  
Acid Component ◽  
Degradation Reactions ◽  
Polyglucuronic Acid

Summary Polonowski type degradation reactions are a major reason for the frequently observed instability of solutions of cellulose in N-methylmorpholine-N-oxide monohydrate (NMMO, 1). The degradation is induced by degradation products of cellulose and NMMO generated in situ in the Lyocell system. The presence of both an amine component, such as morpholine or N-methylmorpholine, and an acid component is required for the decomposition process to proceed. The latter might be a low-molecular-weight compound, such as formic acid, acetic acid or gluconic acid, or also a high-molecular-weight acid, such as polyglucuronic acid or ion exchange resin.

Movements of Phosphorus Between its Biologically Important Forms in Lake Water

1973 ◽  
Vol 30 (10) ◽  
pp. 1525-1536 ◽  
Author(s):  
D. R. S. Lean
Keyword(s):  
Molecular Weight ◽  
Lake Water ◽  
Membrane Filtration ◽  
Organic Phosphorus ◽  
Gel Filtration ◽  
Particulate Fraction ◽  
Low Molecular Weight ◽  
Radioactive Phosphorus ◽  
Dissolved Phosphorus ◽  
Kinetics Of

A model consistent with the kinetics of phosphorus in epilimnetic lake water was developed. Adding 32PO4 to lake water and separating the major forms of dissolved phosphorus by Sephadex gel filtration showed that the exchange mechanism between inorganic phosphate and the particulate fraction predominates. At the same time, a low-molecular-weight phosphorus compound is excreted which combines with colloids in lake water, releasing phosphate from the colloid and making the phosphate available for "transfer" again. This rapid cycling of phosphorus between the four principal forms — the particulate fraction, the low-molecular-weight P compound, colloidal P, and phosphate — appears to contribute to formation of colloids in lake water. No direct complexing of phosphate to the colloid was observed. Only in the presence of algae, bacteria, and other particulate matter did the radioactive phosphorus move to the low-molecular weight and the colloidal forms. The low-molecular-weight compound is negatively charged, as is the colloidal P, but to a lesser degree. Both are removed by anion exchange materials along with phosphate, but the rate that they move into the fraction removed by membrane filtration is different from that for phosphate. When filtrate is refiltered a large amount of the colloidal P is retained by the filter. This complicates measurements of transfer and makes previous studies on utilization of dissolved organic phosphorus of doubtful value since corrections for filter retention were rarely, if ever, made.

scholarly journals A simple method for the production of low molecular weight hyaluronan by in situ degradation in fermentation broth

e-Polymers ◽  
2019 ◽  
Vol 19 (1) ◽  
pp. 477-481
Author(s):  
Jianfeng Mei ◽  
Zhihong Dong ◽  
Yu Yi ◽  
Yanlu Zhang ◽  
Guoqing Ying
Keyword(s):  
Molecular Weight ◽  
Enzymatic Degradation ◽  
Fermentation Broth ◽  
Low Molecular Weight ◽  
Streptococcus Zooepidemicus ◽  
Medium Ph ◽  
Simple Method ◽  
Suitable Temperature ◽  
In Situ Degradation

AbstractFermentation of hyaluronan (HA) by Streptococcus zooepidemicus was carried out in a 10-L fermentor. When the medium pH was controlled at 7.0 and the temperature was maintained at 38°C for 12 h followed by 35°C for 8 h, the yield of HA was 4.83 g/L with a molecular weight of 1,890 kDa. After the cells were removed by centrifugation from the fermentation broth, HA was slowly degraded to low molecular weight HA by hyaluronidase at a suitable temperature without a decrease in HA concentration. If the time and temperature for enzymatic degradation were controlled, the desired low molecular weight HA could be obtained by in situ degradation in the fermentation broth. The method does not require the addition of exogenous hyaluronidase, and is a simple way to produce low molecular weight HA.

scholarly journals Multi Self-Healable UV Shielding Polyurethane/CeO2 Protective Coating: The Effect of Low-Molecular-Weight Polyols

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1947
Author(s):  
Mohammad Mizanur Rahman ◽  
Rami Suleiman ◽  
Md. Hasan Zahir ◽  
Aasif Helal ◽  
A. Madhan Kumar ◽  
...  
Keyword(s):  
Molecular Weight ◽  
In Situ Polymerization ◽  
Outdoor Exposure ◽  
Low Molecular Weight ◽  
Self Healing ◽  
Polydimethyl Siloxane ◽  
Molecular Weights ◽  
Uv Shielding ◽  
Ceo2 Coating

We prepared a series of polyurethane (PU) coatings with defined contents using poly(tetramethylene oxide)glycol (PTMG) with two different molecular weights (i.e., Mn = 2000 and 650), as well as polydimethyl siloxane (PDMS) with a molecular weight of Mn 550. For every coating, maximum adhesive strength and excellent self-healing character (three times) were found using 6.775 mol% mixed with low-molecular-weight-based polyols (PU-11-3-3). Defined 1.0 wt% CeO2 was also used for the PU-11-3-3 coating (i.e., PU-11-3-3-CeO2) to obtain UV shielding properties. Both the in situ polymerization and blending processes were separately applied during the preparation of the PU-11-3-3-CeO2 coating dispersion. The in situ polymerization-based coating (i.e., PU-11-3-3-CeO2-P) showed similar self-healing properties. The PU-11-3-3-CeO2-P coating also showed excellent UV shielding in real outdoor exposure conditions.

In situ formation of AuNPs using fatty N-acylamino hydrazide organogelators as templates

2019 ◽  
Vol 43 (1) ◽  
pp. 295-303 ◽  
Author(s):  
Renata Ongaratto ◽  
Naiane Conte ◽  
Caroline R. Montes D’Oca ◽  
Rafael C. Brinkerhoff ◽  
Caroline Pires Ruas ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Gold Nanoparticles ◽  
Low Molecular Weight ◽  
In Situ Formation ◽  
First Time

This work reports, for the first time, the synthesis of new fatty N-acylamino hydrazides and demonstrates the activity of these compounds as low-molecular-weight organic gelators and templates for preparation of gold nanoparticles (AuNPs).

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