Hydrophobically Modified Dendrimers as Inverse Micelles:  Formation of Cylindrical Multidendrimer Nanostructures

2001 ◽  
Vol 34 (19) ◽  
pp. 6701-6707 ◽  
Author(s):  
Franziska Gröhn ◽  
Barry J. Bauer ◽  
Eric J. Amis
Keyword(s):  
Inverse Micelles ◽  
Hydrophobically Modified

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.

scholarly journals Correction: Space charge limited release of charged inverse micelles in non-polar liquids

2021 ◽  
Author(s):  
Manoj Prasad ◽  
Filip Strubbe ◽  
Filip Beunis ◽  
Kristiaan Neyts
Keyword(s):  
Space Charge ◽  
Chem Phys ◽  
Polar Liquids ◽  
Inverse Micelles ◽  
Phys Chem Chem Phys ◽  
Space Charge Limited

Correction for ‘Space charge limited release of charged inverse micelles in non-polar liquids’ by Manoj Prasad et al., Phys. Chem. Chem. Phys., 2016, 18, 19289–19298, DOI: 10.1039/C6CP03544B.

scholarly journals Antibacterial Activity of N,O-Acylated Chitosan Derivative

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 107
Author(s):  
Agnieszka Piegat ◽  
Anna Żywicka ◽  
Agata Niemczyk ◽  
Agata Goszczyńska
Keyword(s):  
Escherichia Coli ◽  
Antibacterial Activity ◽  
Chitosan Derivative ◽  
Modified Chitosan ◽  
Microdilution Method ◽  
Hydrophobically Modified ◽  
Mechanism Of Interaction ◽  
H Pylori ◽  
Living Bacteria ◽  
Antibacterial Potential

The antibacterial activity of N,O-acylated chitosan derivative with linoleic acid (CH_LA) was tested by disc and well diffusion, agar impregnation and microdilution methods against Staphylococcus aureus, Escherichia coli and Helicobacter pylori strains. Hydrophobically modified chitosan (HMC) was expected to exhibit enhanced antibacterial activity and specific mucin interactions. Although diffusion tests have not indicated the antibacterial potential of chitosan (CH) or CH_LA, the results of the microdilution method demonstrated that tested polymers significantly reduced the amount of living bacteria cells in different concentrations depending on the microorganism. Additionally, CH_LA was characterized by enhanced antibacterial activity compared to CH, which may suggest a different mechanism of interaction with S. aureus and H. pylori. Furthermore, the UV-VIS analysis revealed that the amphiphilic character of derivative led to strong CH_LA–mucin interactions. The study proved the high potential of CH_LA in antibacterial applications, especially for the gastrointestinal tract.

scholarly journals Effect of hydrophobically modified PEO polymers (PEO-dodecyl) on oil/water microemulsion properties: in vitro and in silico investigations

RSC Advances ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 7059-7069
Author(s):  
M. Khatouri ◽  
R. Ahfir ◽  
M. Lemaalam ◽  
S. El Khaoui ◽  
A. Derouiche ◽  
...  
Keyword(s):  
Integral Equations ◽  
In Silico ◽  
Md Simulations ◽  
Hydrophobically Modified ◽  
Oil Water

In this work, we study the effect of grafted PEO-dodecyl co-polymers on the decane/water microemulsions properties. For this purpose, we combined the MD simulations, the OZ integral equations resolved using the HNC closure, and SANS experiments.

scholarly journals Interaction and Adsorption of Hydrophobically Modified Polyacrylamide on Silica and Asphaltene Surfaces

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Wenjie Zou ◽  
Zichuan Fang ◽  
Zhijun Zhang ◽  
Zhenzhen Lu
Keyword(s):  
Oil Recovery ◽  
Adhesion Force ◽  
Interaction Mechanism ◽  
Surface Force ◽  
Industrial Applications ◽  
Oil Sand ◽  
Continuous Adsorption ◽  
Hydrophobically Modified Polyacrylamide ◽  
Hydrophobically Modified ◽  
Modified Polyacrylamide

The adsorption of polymers affects the cost and oil recovery in oil reservoir exploitation and the flocculation effect in the treatment of oil sand tailings. The adhesion and adsorption of a hydrophobically modified polyacrylamide (HMPAM), i.e., P(AM-NaAA-C16DMAAC), on silica and asphaltene were investigated using surface force measurements, thermodynamic analysis and quartz crystal microbalance with dissipation (QCM-D) measurement. Our study indicates that HMPAM polymer has strong interaction with both silica and asphaltene. The adhesion force of HMPAM on silica was stronger than that on asphaltene surface. Consistently, the adsorption of HMPAM was also greater on silica surface, with a more rigid layer formed on the surface. For HMPAM/silica system, the attractive interaction and the strong adhesion are mainly driven by the hydrogen bonding and electrostatic interaction. For HMPAM/asphaltene system, it is mainly due to hydrophobic interaction between the long hydrocarbon chains of HMPAM and asphaltene. Furthermore, continuous adsorption of HMPAM was detected and multiple layers formed on both silica and asphaltene surfaces, which can be attributed to the hydrophobic chains of HMPAM polymers. This work has illustrated the interaction mechanism of HMPAM polymer on hydrophilic silica and hydrophobic asphaltene surfaces, which provide insight into the industrial applications of hydrophobically modified polymer.

scholarly journals Hydrophobically Modified Isosorbide Dimethacrylates as a Bisphenol-A (BPA)-Free Dental Filling Material

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2139
Author(s):  
Bilal Marie ◽  
Raymond Clark ◽  
Tim Gillece ◽  
Seher Ozkan ◽  
Michael Jaffe ◽  
...  
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Flexural Strength ◽  
Bisphenol A ◽  
Water Sorption ◽  
Triethylene Glycol ◽  
Filling Material ◽  
Hydrophobically Modified ◽  
Free Replacement

A series of bio-based hydrophobically modified isosorbide dimethacrylates, with para-, meta-, and ortho- benzoate aromatic spacers (ISBGBMA), are synthesized, characterized, and evaluated as potential dental restorative resins. The new monomers, isosorbide 2,5-bis(4-glyceryloxybenzoate) dimethacrylate (ISB4GBMA), isosorbide 2,5-bis(3-glyceryloxybenzoate) dimethacrylate (ISB3GBMA), and isosorbide 2,5-bis(2-glyceryloxybenzoate) dimethacrylate (ISB2GBMA), are mixed with triethylene glycol dimethacrylate (TEGDMA) and photopolymerized. The resulting polymers are evaluated for the degree of monomeric conversion, polymerization shrinkage, water sorption, glass transition temperature, and flexural strength. Isosorbide glycerolate dimethacrylate (ISDGMA) is synthesized, and Bisphenol A glycerolate dimethacrylate (BisGMA) is prepared, and both are evaluated as a reference. Poly(ISBGBMA/TEGDMA) series shows lower water sorption (39–44 µg/mm3) over Poly(ISDGMA/TEGDMA) (73 µg/mm3) but higher than Poly(BisGMA/TEGDMA) (26 µg/mm3). Flexural strength is higher for Poly(ISBGBMA/TEGDMA) series (37–45 MPa) over Poly(ISDGMA/TEGDMA) (10 MPa) and less than Poly(BisGMA/TEGDMA) (53 MPa) after immersion in phosphate-buffered saline (DPBS) for 24 h. Poly(ISB2GBMA/TEGDMA) has the highest glass transition temperature at 85 °C, and its monomeric mixture has the lowest viscosity at 0.62 Pa·s, among the (ISBGBMA/TEGDMA) polymers and monomer mixtures. Collectively, this data suggests that the ortho ISBGBMA monomer is a potential bio-based, BPA-free replacement for BisGMA, and could be the focus for future study.

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