Complexations of Beta-Cyclodextrin with Surfactants and Hydrophobically Modified Ethoxylated Urethanes

2000 ◽  
pp. 254-270 ◽  
Author(s):  
Zeying Ma ◽  
J. Edward Glass
Keyword(s):  
Hydrophobically Modified ◽  
Beta Cyclodextrin

Influence of Polymer Charge, Temperature, and Surfactants on Surface Sizing of Liner and Greaseproof Paper With Hydrophobically Modified Starch

TAPPI Journal ◽  
2009 ◽  
Vol 8 (2) ◽  
pp. 33-38 ◽  
Author(s):  
ANNA JONHED ◽  
LARS JÄRNSTRÖM
Keyword(s):  
Phase Separation ◽  
Contact Angles ◽  
Low Ph ◽  
Hydrophobically Modified ◽  
Paper Sizing ◽  
Surface Sizing ◽  
Separation Temperature ◽  
Hydrophobic Nature ◽  
Sizing Agents ◽  
Charge Temperature

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.

Controlling porosity and density of nanocellulose aerogels for superhydrophobic light materials

TAPPI Journal ◽  
2018 ◽  
Vol 17 (03) ◽  
pp. 145-153 ◽  
Author(s):  
Chengua Yu ◽  
Feng Wang ◽  
Shiyu Fu ◽  
Lucian Lucia
Keyword(s):  
Contact Angle ◽  
Freeze Drying ◽  
Engine Oil ◽  
High Porosity ◽  
Water Mixture ◽  
Waste Engine Oil ◽  
Hydrophobically Modified ◽  
Static Contact ◽  
Oil Water ◽  
Hydrophobic Material

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.

Macrophage Adhesion and Phenotypic Shifts on Hydrophobically Modified Hydrogels

2019 ◽  
Author(s):  
Zihao Xu ◽  
Doh-Gyu Hwang ◽  
Michael D. Bartlett ◽  
Shan Jiang ◽  
Kaitlin M. Bratlie
Keyword(s):  
Hydrophobically Modified ◽  
Macrophage Adhesion

Copolymer Micelles with Polyelectrolyte Shell in Aqueous Media. A Mean-Field Study

2006 ◽  
Vol 71 (5) ◽  
pp. 756-768 ◽  
Author(s):  
Karel Jelínek ◽  
Filip Uhlík ◽  
Zuzana Limpouchová ◽  
Pavel Matějíček ◽  
Karel Procházka
Keyword(s):  
Aqueous Media ◽  
Excitation Energy Transfer ◽  
Mean Field ◽  
Hydrophobically Modified ◽  
Small Influence ◽  
Covalently Bonded ◽  
Self Consistent Field ◽  
Copolymer Micelles ◽  
And Behavior ◽  
Scf Calculations

The multimolecular micelles formed by polystyrene-block-poly(methacrylic acid) (PS-PMA) copolymer and by hydrophobically modified PS-PMA copolymer with naphthalene and anthracene (PS-N-PMA-A) were studied by self-consistent field (SCF) calculations in aqueous media. The labeling with covalently bonded naphthalene between PS and PMA blocks and with anthracene at the free end of PMA blocks, which is suitable for experimental nonradiative excitation energy transfer (NRET) studies of PS-N-PMA-A micelles, modifies the structure of micellar shell. The study was aimed at understanding structure and behavior of micelles at different pH and ionic strength. The results show that the presence of hydrophobic tags has only a small influence on the overall structure of micelles but it strongly affects the distribution of PMA free ends. The hydrophobic labels (anthracenes) try to return into the shell and their certain fraction is localized close to the core/shell interface, which causes a fairly high NRET efficiency. The calculated and experimentally measured NRET efficiency were compared; their trends are reasonable at the semiquantitative level.

Sign in / Sign up

Export Citation Format

Share Document