• Bulletin of the Korean Chemical Society
• /
• v.33 no.7
• /
• pp.2187-2192
• /
• 2012

This study presents a facile way synthesizing disc-like lipid bilyaer nanostructures with a cationic amphiphilic polyelectrolyte. The cationic amphiphilic polyelectrolyte was in a form of partially quarternized copolymer and was synthesized with 2-(dimethylamino)ethyl methacrylate and stearyl methacrylate. At some concentration ranges of the polymer, the addition of the polymer to lipid components during the preparation of bilayer nanostructures resulted in discs with a fairly high yield (~99%). The mechanism for the formation of the nanostructures was discussed based on the physical properties of these nanostructures and by comparing the nanostructures obtained with an anionic amphiphilic polyelectrolyte.

• Polymer(Korea)
• /
• v.39 no.3
• /
• pp.403-411
• /
• 2015

A series of hydrophobically associating fluorinated amphiphilic polyacrylamide copolymers with remarkably high heat resistance and salt tolerance were synthesized by free radical micellar copolymerization, using acrylamide (AM) and sodium 2-acrylamido-tetradecane sulfonate ($AMC_{14}S$) as amphiphilic monomers, and 2-(perfluorooctyl) ethyl acrylate (PFHEA) as hydrophobic monomer. The structure of the terpolymer was characterized by FTIR, $^1H$ NMR and $^{19}F$ NMR. The solution properties of the terpolymers were investigated in details, and the results showed that the terpolymer solution had strong intermolecular hydrophobic association as the concentration exceeded the critical association concentration 1.5 g/L. The terpolymer solution possessed high surface activity, viscoelasticity, excellent heat resistance, salt tolerance and shearing resistance. The viscosity retention rate of copolymer solution was as high as 59.9% under the condition of fresh wastewater, $85^{\circ}C$ and a 60-days aging test.

• Membrane and Water Treatment
• /
• v.10 no.6
• /
• pp.461-469
• /
• 2019

In the present work, we present a new effective hydrophilicity modifier for polysulfone (PSf) membrane. Firstly, amphiphilic nanocellulose (ANC) with different substitution degrees (SD) was synthesized by esterification reaction with nanocellulose (NC) and dodecyl succinic anhydride (DDSA). The SD and morphology of ANC were characterized by titration method and transmission electron microscopy (TEM). Then, the polysulfone (PSf)/ANC blend membranes were prepared via an immersion phase inversion method. The influence of SD on the morphology, structure and performances of PSf/ANC blend membrane were carefully investigated by Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), mechanical property test, contact angle measuring instrument and filtration experiment. The results showed that the mechanical property, hydrophilicity and anti-fouling property of all the PSf/ANC blend membranes were higher than those of pure PSf membrane and PSf/NC membrane, and the membrane properties were increased with the increasing of SD values. As ANC-4 has the highest SD value, PSf/ANC-4 membrane exhibited the optimal membrane properties. In conclusion, the prepared ANC can be used as an additive to improve the hydrophilicity and anti-fouling properties of polysulfone (PSf) membrane.

• Bulletin of the Korean Chemical Society
• /
• v.29 no.10
• /
• pp.1887-1892
• /
• 2008

Novel poly(aspartic acid) derivatives conjugated with L-lysine moieties and their amphiphilic analogs were synthesized and characterized. The chemical structures of these polymers were confirmed using FT-IR and $^1HNMR$ spectroscopy. The physicochemical properties of amphiphilic copolymers were characterized using an electrophonetic light scattering spectrophotometer (ELS) and transmission electron microscopy (TEM). These results indicated a stable nanoparticle formation within aqueous media. These polymers have potential applications in the pharmaceutical and cosmetic fields as delivery vehicles for bioactive molecules.

• Journal of Industrial and Engineering Chemistry
• /
• v.68
• /
• pp.209-219
• /
• 2018

Colloidally stable organic-inorganic (O-I) hybrid nanoparticles could be prepared using an alkoxysilanefunctionalized amphiphilic polymer (AFAP) precursor. O-I hybrid sols could maintain colloidal stability for six months even at 45% solid content and be coated onto glass as well as PET film to form transparent O-I hybrid films. The formation of O-I hybrid nanoparticles dispersed in cured coating films could be confirmed using scanning electron microscopy. The cured coating film showed 3H and 5H pencil hardness on PET and glass, respectively. Nanoindentation measurements also showed that their modulus and hardness was varied with the type of AFAP used in its preparation.

• Journal of Microbiology and Biotechnology
• /
• v.20 no.10
• /
• pp.1424-1429
• /
• 2010

A poly(${\gamma}$-glutamic acid) (${\gamma}$PGA)-cholesterol conjugate was synthesized and its properties were then evaluated. The conjugate exhibited an amphiphilic nature derived from the hydrophilic ${\gamma}$PGA backbone and the hydrophobic cholesterol side chain. The conjugate spontaneously formed nanoparticles, becoming an aqueous solution when at low concentrations, and at high concentrations the result was the formation of a physical gel. By utilizing the self-aggregating properties of the conjugate in water, an artificial chaperone was developed. A complex of protein, with the nanoparticles of the conjugate, was formed and the protein was released upon the dissociation of the nanoparticles through the addition of ${\beta}$-cyclodextrin. For denatured carbonic anhydrase, the activity was recovered in the artificial chaperone of the nanoparticle conjugate.

• Bulletin of the Korean Chemical Society
• /
• v.31 no.12
• /
• pp.3740-3744
• /
• 2010

A typically designed 'Peptide Lego' has two distinct surfaces: a hydrophilic side that contains the complete charge distribution and a hydrophobic side. In this article, we describe the fabrication of a unique lego-type peptide with the AEAEYAKAK sequence. The novel peptide with double amphiphilic surfaces is different from typical peptides due to special arrangement of the residues. The results of CD, FT-IR, AFM and DLS demonstrate that the peptide with the random coil characteristic was able to form stable nanostructures that were mediated by non-covalent interactions in an aqueous solution. The data further indicated that despite its different structure, the peptide was able to undergo self-assembly similar to a typical peptide. In addition, the use of hydrophobic pyrene as a model allowed the peptide to provide a new type of potential nanomaterial for drug delivery. These efforts collectively open up a new direction in the fabrication of nanomaterials that are more perfect and versatile.

• Proceedings of the Korean Fiber Society Conference
• /
• 2001.04b
• /
• pp.351-354
• /
• 2001

• Proceedings of the Materials Research Society of Korea Conference
• /
• 1998.11a
• /
• pp.103-103
• /
• 1998

• Proceedings of the Materials Research Society of Korea Conference
• /
• 1998.11a
• /
• pp.118-118
• /
• 1998