Complex Coacervation of Hydrophobically Modified Gelatin and Poly(ethyleneimine)

Author(s):  
Tae Hoon Kim ◽  
Hyeon Ki Son ◽  
Jin-Chul Kim
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.


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

2006 ◽  
Vol 71 (5) ◽  
pp. 756-768 ◽  
Author(s):  
Karel Jelínek ◽  
Filip Uhlík ◽  
Zuzana Limpouchová ◽  
Pavel Matějíček ◽  
Karel Procházka

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.


ACS Omega ◽  
2020 ◽  
Vol 5 (51) ◽  
pp. 33064-33074
Author(s):  
Preeti Tiwari ◽  
Indu Bharti ◽  
Himadri B Bohidar ◽  
Shabina Quadir ◽  
Mohan C Joshi ◽  
...  

2021 ◽  
Vol 126 (23) ◽  
Author(s):  
Debra J. Audus ◽  
Samim Ali ◽  
Artem M. Rumyantsev ◽  
Yuanchi Ma ◽  
Juan J. de Pablo ◽  
...  

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 107
Author(s):  
Agnieszka Piegat ◽  
Anna Żywicka ◽  
Agata Niemczyk ◽  
Agata Goszczyńska

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.


RSC Advances ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 7059-7069
Author(s):  
M. Khatouri ◽  
R. Ahfir ◽  
M. Lemaalam ◽  
S. El Khaoui ◽  
A. Derouiche ◽  
...  

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.


2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Wenjie Zou ◽  
Zichuan Fang ◽  
Zhijun Zhang ◽  
Zhenzhen Lu

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.


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