Novel hydrophobically modified agarose cryogels fabricated using dimethyl sulfoxide

Author(s):  
Courtney Evans ◽  
Yuto Morimitsu ◽  
Rikako Nishi ◽  
Masahiro Yoshida ◽  
Takayuki Takei
2020 ◽  
Vol 993 ◽  
pp. 1407-1416 ◽  
Author(s):  
Zheng Li ◽  
Zi Jian He ◽  
Ying Cheng Zhou ◽  
Yi Tang ◽  
Yu Fang Chen ◽  
...  

In this paper, Dimethyl sulfoxide (DMSO) was used in the activating process of cotton filter cloth to improve its further hydrophobic modification reaction between cotton fabric and 1-octadecene via an electron transfer (ARGET) atom transfer radical polymerization (ATRP) mechanism. The major influences of DMSO on ARGET-ATRP process was discussed, and meanwhile, the microstructure changes, morphology feature and performance characteristics of cotton filter cloth during the reaction was explored by the SEM, AFM, EDS, XRD and TGA techniques.The result shows that DMSO can leads to cotton fibers adhesion and surface roughening under the ARGET-ATRP grafting reaction conditions, but has little changes on the crystal form, crystallinity and thermal properties of cellulose. At a DMSO dosage of 10%, the hydrophobically modified cotton filter cloth has a water contact angle (CA) of up to 141°. While naturally placed for 1 hour, the CA of hydrophobically modified cotton filter cloth can be stable at 116° with a decay rate of 17.5%, which proves that the hydrophobic stability of cotton filter cloth has been improved markedly. Furthermore, a better improvement for the hydrophobic stability of cotton filter cloth will significantly enhance the application of hydrophobic functional modified cellulosic materials.


Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 291
Author(s):  
Huai N. Cheng ◽  
Atanu Biswas ◽  
Sanghoon Kim ◽  
Carlucio R. Alves ◽  
Roselayne F. Furtado

Xylan is a major type of hemicellulose that has attracted a lot of research and development activities. It is often derivatized in order to improve its properties. In the literature, hydrophobic modification of polymers is often used to produce surfactant-like materials and associative thickeners. In this work, we have derivatized xylan with alkyl ketene dimer (AKD) and two types of alkenyl succinic anhydrides (ASAs). The xylan-AKD derivatives have been made at 90 °C, using dimethyl sulfoxide as solvent and 4-dimethylaminopyridine as promoter. Samples with degrees of substitution (DS) up to 0.006 have been produced. The xylan-ASA derivatives have been synthesized at 120 °C in dimethyl sulfoxide with DS up to 0.105–0.135. The structures of these products have been confirmed with NMR and FT-IR. These xylan derivatives increase the structural diversity of xylan and provide additional options for people seeking to use hydrophobically modified polysaccharides in their applications.


1976 ◽  
Vol 36 (01) ◽  
pp. 221-229 ◽  
Author(s):  
Charles A. Schiffer ◽  
Caroline L. Whitaker ◽  
Morton Schmukler ◽  
Joseph Aisner ◽  
Steven L. Hilbert

SummaryAlthough dimethyl sulfoxide (DMSO) has been used extensively as a cryopreservative for platelets there are few studies dealing with the effect of DMSO on platelet function. Using techniques similar to those employed in platelet cryopreservation platelets were incubated with final concentrations of 2-10% DMSO at 25° C. After exposure to 5 and 10% DMSO platelets remained discoid and electron micrographs revealed no structural abnormalities. There was no significant change in platelet count. In terms of injury to platelet membranes, there was no increased availability of platelet factor-3 or leakage of nucleotides, 5 hydroxytryptamine (5HT) or glycosidases with final DMSO concentrations of 2.5, 5 and 10% DMSO. Thrombin stimulated nucleotide and 5HT release was reduced by 10% DMSO. Impairment of thrombin induced glycosidase release was noted at lower DMSO concentrations and was dose related. Similarly, aggregation to ADP was progressively impaired at DMSO concentrations from 1-5% and was dose related. After the platelets exposed to DMSO were washed, however, aggregation and release returned to control values. Platelet aggregation by epinephrine was also inhibited by DMSO and this could not be corrected by washing the platelets. DMSO-plasma solutions are hypertonic but only minimal increases in platelet volume (at 10% DMSO) could be detected. Shrinkage of platelets was seen with hypertonic solutions of sodium chloride or sucrose suggesting that the rapid transmembrane passage of DMSO prevented significant shifts of water. These studies demonstrate that there are minimal irreversible alterations in in vitro platelet function after short-term exposure to DMSO.


1964 ◽  
Vol 11 (01) ◽  
pp. 222-229 ◽  
Author(s):  
Isaac Djerassi ◽  
Albert Roy ◽  
Jorge Alvarado ◽  

SummaryHuman platelets frozen at −195° C (liquid nitrogen) retain their morphological integrity and ability to promote clot retraction when 5% dimethyl-sulfoxide and 5% dextrose are added to the suspending plasma medium. Slow freezing was more effective than direct immersion in the liquid nitrogen. Although similar results may be achieved with dimethylsulfoxide alone with rigidly controlled freezing rates, the addition of sugars may permit freezing under less critical conditions.Dimethylsulfoxyd und 5% Dextrose dem Plasmamilieu hinzugefügt werden. Das langsame Einfrieren ist effektiver als das direkte Eintauchen in flüssigen Stickstoff. Obschon ähnliche Resultate mit Dimethylsulfoxyd allein unter exakter Kontrolle der Einfrierungsgeschwindig-keit erreicht werden können, erlaubt die Zugabe von Dextrose ein Einfrieren unter weniger kritischen Bedingungen.


TAPPI Journal ◽  
2009 ◽  
Vol 8 (2) ◽  
pp. 33-38 ◽  
Author(s):  
ANNA JONHED ◽  
LARS JÄRNSTRÖM

The aim of this study was to investigate the properties of hydrophobically modified (HM) quaterna-ry ammonium starch ethers for paper sizing. These starches possess temperature-responsive properties; that is, gelation or phase separation occurs at a certain temperature upon cooling. This insolubility of the HM starches in water at room temperature improved their performance as sizing agents. The contact angles for water on sized liner were substantially larger than on unsized liner. When the application temperature was well above the critical phase-separation temperature, larger contact angles were obtained for liner independently of pH compared with those at the lower application temperature. Cobb60 values for liner decreased upon surface sizing, with a low pH and high application temperature giving lower water penetration. Contact angles on greaseproof paper decreased upon sur-face sizing as compared to unsized greaseproof paper, independently of pH and temperature. Greaseproof paper showed no great difference between unsized substrates and substrates sized with HM starch at different pH. This is probably due to the already hydrophobic nature of greaseproof paper. However, the Cobb60 values increased at low pH and low application temperature. Surfactants were added to investigate how they affect the sized surface. Addition of surfactant reduces the contact angles, in spite of indications of complex formation.


TAPPI Journal ◽  
2018 ◽  
Vol 17 (03) ◽  
pp. 145-153 ◽  
Author(s):  
Chengua Yu ◽  
Feng Wang ◽  
Shiyu Fu ◽  
Lucian Lucia

A very low-density oil-absorbing hydrophobic material was fabricated from cellulose nanofiber aerogels–coated silane substances. Nanocellulose aerogels (NCA) superabsorbents were prepared by freeze drying cellulose nanofibril dispersions at 0.2%, 0.5%, 0.8%, 1.0%, and 1.5% w/w. The NCA were hydrophobically modified with methyltrimethoxysilane. The surface morphology and wettability were characterized by scanning electron microscopy and static contact angle. The aerogels displayed an ultralow density (2.0–16.7 mg·cm-3), high porosity (99.9%–98.9%), and superhydrophobicity as evidenced by the contact angle of ~150° that enabled the aerogels to effectively absorb oil from an oil/water mixture. The absorption capacities of hydrophobic nanocellulose aerogels for waste engine oil and olive oil could be up to 140 g·g-1 and 179.1 g·g-1, respectively.


2008 ◽  
Vol 59 (1) ◽  
pp. 45-48
Author(s):  
Oana Ciocirlan ◽  
Olga Iulian

This paper reports the viscosities measurements for the binary system dimethyl sulfoxide + 1,4-dimethylbenzene over the entire range of mole fraction at 298.15, 303.15, 313.15 and 323.15 K and atmospheric pressure. The experimental viscosities were correlated with the equations of Grunberg-Nissan, Katti-Chaudhri, Hind, Soliman and McAllister; the adjustable binary parameters have been obtained. The excess Gibbs energy of activation of viscous flow (G*E) has been calculated from the experimental measurements and the results were fitted to Redlich-Kister polynomial equation. The obtained negative excess Gibbs free energy of activation and negative Grunberg-Nissan interaction parameter are discussed in structural and interactional terms.


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