• Journal of Adhesion and Interface
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• v.16 no.1
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• pp.6-14
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• 2015

In this study, physically and chemically stable core-crosslinked amphiphilic polymer (CCAP) nanoparticles were prepared using amphiphilic reactive precursors via soap-free emulsion process. Obtained CCAP nanoparticles were used as templates for synthesis of nanostructured $TiO_2$ nanoparticles. First, CCAP nanoparticles dispersed aqueous solutions were mixed with titanium isopropoxide to prepare stable organic-inorganic hybrid sols, and then obtained sols were spin coated onto glass substrate to prepare hybrid thin films onto glass, and then hybrid thin films were calcinated at various temperature to remove CCAP. Nanostructure of calcinated thin fims were examined by SEM. To study effect of CCAP nanoparticles on nanostructure of $TiO_2$ nanoparticles, the morphology of $TiO_2$ nanoparticles prepared using various CCAP templates was compared with that of $TiO_2$ nanoparticles prepared using conventional organic template, nonionic surfactant, Triton X-100.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.287-287
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• 2006

Amphiphilic random copolymers can form various types of micelles in aqueous media depending on the balance between two opposite interactions- electrostatic repulsion and hydrophobic attraction. This balance can change by addition of some organic solvent to the aqueous solution, and as a result, we can control the micellar structure and micellization equilibrium by changing the solvent content. In the present study, we have investigated the micellization equilibrium of an amphiphilic statistical copolymer consisting of sodium 2-(acrylamido)-2- methylpropanesulfonate and hexyl methacrylate in mixtures of water and methanol by sedimentation equilibrium and fluorescence.

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

• Bulletin of the Korean Chemical Society
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• v.32 no.2
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• pp.620-624
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• 2011

In recent years, the study of self-assembly peptide used in drug delivery system has been attracted great interest from scientists. In the category are self-assembly peptides in the structure either with one hydrophobic surface and another hydrophilic or a hydrophobic head and a hydrophilic tail. Here, we focus on a novel designed peptide EYK with double amphiphilic surfaces, investigating on the capability of peptide as a carrier for hydrophobic compound model pyrene. The fluorescence data presented the dynamic process of the transfer, showing that the pyrene was in the crystalline form in peptide solution, and molecularly migrated from its peptide encapsulations into the membrane bilayers when the peptide-pyrene suspension was mixed with liposome vesicles. The results indicated that the peptide EYK could stabilize hydrophobic pyrene in aqueous solution and delivered it into EPC liposome as a potential carrier.

• Macromolecular Research
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• v.16 no.8
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• pp.711-716
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• 2008

We synthesized gold nanonetwork using the amphiphilic polymer brush, poly(oxyethylene) containing decyltri(oxyethylene)thiomethyl ($C_{10}H_{21}(OCH_2CH_2)_3SCH_2-$) side groups, as a stabilizer and/or a template. When tetrabutylammonium borohydride solution in THF was added to a mixture solution of the polymer and $LiAuCl_4$ in THF, 0-D gold nanomaterials were obtained. However, when an aqueous solution of sodium borohydride was added, gold nanonetworks were synthesized. The composites composed of polymer/0-D gold nanomaterials and polymer/gold nanonetworks showed electrical conductivities of ${\sim}10^{-9}$ and ${\sim}10^{-3}S/cm$, respectively, which indicated that the gold nanonetworks increased the electrical conductivity.

• Proceedings of the Membrane Society of Korea Conference
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• 1995.04a
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• pp.16-20
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• 1995

The spontaneous self-organization of amphiphilic molecules into complex aggregates was undoubtedly an important factor in the emergence of life on earth. We study the parameters governing the self-organization of a simple amphiphilic model system using electron cryomicroscopy of ice-embedded specimens in combination with extensive data analysis. Different stable helices can be generated reproducibly by changing the parameters controlling the molecular aggregation process. The repeating units of the helical aggregates in the micrographs can be found by multivariate statistical image analysis techniques, and these two-dimensional projection images suffice for calculating the three-dimensional density distribution of the fibers. We present a typical structure consisting of a narrow stack of compartmented bilayers twisted into a left-handed helix. Our new techniques directly elucidate the three-dimensional structure of helical assemblies, and can complement or replace diffraction-based approaches.

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

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.442-445
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• 2000

Amphiphilic polyurethane(APU) particle is a polymeric surfactant, and could increase the solubility of 2-methylnaphthalene significantly. 2-Methylnaphthalene was recovered by the precipitation of APU particles and was degraded by Acinetobacter sp. K2-2. APU particle was recovered and reused after treatment of triethylamine.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.23 no.1
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• pp.145-158
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• 1997

Lipid를 이용하여 보다 안정한 microemulsion을 제조함에 있어 Zeta potential을 이요하여 비교 분석 하여 보았다. 실험 시 Lipid Base와 Cetyl phosphate의 함량변화가 particle size와 zeta potential에 미치는 영향에 대하여 실험을 수행하였으며, zeta potetial의 시간 경과에 따른 경시변황 대하뎌도 조사하여 microemulsion의 적정조건을 찾을 수 있었다. microemulsion과 emulsion에 대하여 안전성을 비교 관찰 하였다.

• Applied Chemistry for Engineering
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• v.30 no.3
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• pp.308-312
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• 2019

Amphiphilic gold nanoparticles were synthesized by the functionalization of gold nanoparticles with hydrophilic and hydrophobic ligands on their surfaces, which can be applied to many disciplines such as biology, photonics, electronics, and so on. The ratio of hydrophilic and hydrophobic ligands plays an important role in such applications since the ratio is closely related to physiochemical properties of the nanoparticles. In this paper, the effect of temperature during the ligand exchange reaction on the ratio of ligands on the gold nanoparticle surface was investigated. Hydrophilic ligands have higher affinity to the nanoparticle surface with an increase of the temperature. Furthermore, the amphiphilic nanoparticles at a higher temperature were more soluble in an aqueous solution even with a lower hydrophilicity of the nanoparticle surface.