• Title/Summary/Keyword: self -assembly

Search Result 691, Processing Time 0.031 seconds

Conversion of CdTe Nanoparticles into Nanoribbons via Self-Assembly (CdTe 나노입자의 자기조립과정을 통한 나노리본 합성)

  • Oh, Sooyeoun;Kang, Wan-Kyu;Kang, Jeong Won;Kim, Ki-Sub;Lee, Huen
    • Korean Chemical Engineering Research
    • /
    • v.50 no.6
    • /
    • pp.1082-1085
    • /
    • 2012
  • CdTe nanoribbons feature their unique optical properties compared with CdTe nanoparticles. Slow oxidation of tellurium ions on CdTe nanoparticles resulted in the organization of individual nanoparticle into nanoribbons. The light-controlled self-assembly of CdTe nanoparticles led to twisted ribbons. It was found that irradiation improved the oxidation of tellurium ions. Transmission electron microscopy (TEM) were performed to characterize the synthesized nanostructures and showed nanowires were twisted after self-assembly. The photoluminescence was slightly blue-shifted from 550 to 544 nm. This synthetic procedure could potentially provide a key step toward the fabrication of nanowires.

Surface Modification Silica Nanoparticles by Aerosol Self Assembly (에어로졸 자기조립에 의한 실리카 나노분말의 표면개질)

  • Kil, Dae-Sup;Jang, Hee-Dong;Chang, Han-Kwon;Cho, Kuk;Kim, Sun-Kyung;Oh, Kyoung-Joon;Choi, Jin-Hoon
    • Korean Journal of Materials Research
    • /
    • v.20 no.2
    • /
    • pp.78-81
    • /
    • 2010
  • Surface modification of silica nanoparticles was investigated using an aerosol self assembly. Stearic acid was used as surface treating agent. A two-fluid jet nozzle was employed to generate an aerosol of the colloidal suspension, which contained 20 nm of silica nanoparticles, surface modifier, and ethyl alcohol. Powder properties such as morphology, specific surface area and pore size distribution were analyzed by SEM, BET and BJH methods, respectively. Surface properties of the silica power were analyzed by FT-IR. The OH bond of the $SiO_2$ surface was converted to a C-H bond. It was revealed that the hydrophilic surface changed to a hydrophobic one due to the aerosol self assembly. Morphology of the surface treated powder was nanostructured with lots of pores having an average diameter of around $2\;{\mu}m$. Depending on the stearic acid concentration (0.25 to 1.0 wt%), the pore size distribution of the particles and the degree of hydrophobicity ranged from 1.5 nm to 180 nm and 29.6% to 50.2%, respectively.

Fabrication of Block Copolymer Membranes via SNIPS Process (SNIPS 공정을 이용한 블록공중합체 분리막의 구조 형성에 관한 연구)

  • Woo, Sanghoon;Kim, Jinhee;Lee, Junghyun;Bang, Joona
    • Korean Chemical Engineering Research
    • /
    • v.55 no.2
    • /
    • pp.214-219
    • /
    • 2017
  • In this work, we fabricated PS-b-P4VP block copolymer membranes from self-assembly and non-solvent induced phase separation (SNIPS), which combines the block copolymer self-assembly and conventional NIPS process. While previous studies mostly focused on the fabrication of well-defined structures, we systematically examined various processing parameters such as polymer concentration, solvent evaporation duration, solvent composition, and humidity, to optimized the membrane structures. As a result, the morphology of PS-b-P4VP membranes was optimized at a certain polymer concentration in solution and composition of volatile solvent at low humidity conditions, resulting in SNIPS separation membranes with well-defined nanopores on the surface, 75% of membrane porosity, and 18% of surface porosity.

Revesible Switching between Nematic Gel and Isotriopic Fluid Triggered by External Stimuli in Aqueous Self-Assembly of Supramolecular Nanocylinders

  • Ryu, Ja-Hyoung;Lee, Myong-Soo
    • Proceedings of the Polymer Society of Korea Conference
    • /
    • 2006.10a
    • /
    • pp.308-308
    • /
    • 2006
  • We have demonstrated that the cylindrical micelles self-assembled from coil-rod-coil molecules can be interconnected by addition of a small amount of rod-coil-rod molecule as a bridging agent. Subsequently, these dynamic interconnections lead to stiff bundles composed of cylindrical micelles that are responsible for the formation of a reversible nematic gel. The results described here represent a significant example that dynamic bridging of supramolecular cylinders in aqueous solution can provide a useful strategy to construct one-dimensional nematic structure with three dimensional elastic properties.

  • PDF

Folding of Coordination Polymers into Double-Stranded Helical Organization

  • Kim, Ho-Joong;Lee, Eun-Ji;Lee, Myong-Soo
    • Proceedings of the Polymer Society of Korea Conference
    • /
    • 2006.10a
    • /
    • pp.248-248
    • /
    • 2006
  • The notable feature of the Cu(II) coordination polymer investigated here is its ability to self-assemble into a double-stranded helical structure with regular grooves along the helical axis, through the combination of metal-chloride dimeric interactions and repulsive interactions, as an organizing force. It is also remarkable that the double-stranded helices self-organize into a 2-D columnar structure in both the bulk state and aqueous solution. These results represent a unique example that weak metal-ligand bridging interactions can provide a useful strategy to construct stable double-stranded helical nanotubes.

  • PDF

Fabrication of Biochip by Hydrophobic Interaction (무작위 조립법을 이용한 바이오칩의 제작)

  • Choi, Yong-Sung;Moon, Jong-Dae;Lee, Kyung-Sup
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2006.06a
    • /
    • pp.404-405
    • /
    • 2006
  • Microarray-based DNA chips provide an architecture for multi-analyte sensing. In this paper, we report a new approach for DNA chip microarray fabrication. Multifunctional DNA chip microarray was made by immobilizing many kinds of biomaterials on transducers (particles). DNA chip microarray was prepared by randomly distributing a mixture of the particles on a chip pattern containing thousands of m-scale sites. The particles occupied a different sites from site to site. The particles were arranged on the chip pattern by the random fluidic self-assembly (RFSA) method, using a hydrophobic interaction for assembly.

  • PDF

Fabrication of Hydrophobic/Hydrophilic Pattern as a Template for DNA Chip Microaray (DNA Chip Microarrays를 위한 template로서 소수성 패턴의 제작)

  • Choi, Yong-Sung;Park, Dae-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2004.11a
    • /
    • pp.472-475
    • /
    • 2004
  • Microarray-based DNA chips provide an architecture for multi-analyte sensing. In this paper, we report a new approach for DNA chip microarray fabrication. Multifunctional DNA chip microarray was made by immobilizing many kinds of biomaterials on transducers (particles). DNA chip microarray was prepared by randomly distributing a mixture of the particles on a chip pattern containing thousands of m-scale sites. The particles occupied a different sites from site to site. The particles were arranged on the chip pattern by the random fluidic self-assembly (RFSA) method, using a hydrophobic interaction for assembly.

  • PDF

Supervisory Control for Multi-Processor-Based Automatic Assembly System (다중프로세서 방식의 자동조립시스템을 위한 관리제어)

  • ;;;Zeungnam Bien
    • The Transactions of the Korean Institute of Electrical Engineers
    • /
    • v.39 no.8
    • /
    • pp.888-897
    • /
    • 1990
  • In this paper, a multi-processor-based supervisory control for automatic assembly system is presented. The proposed supervisory control is organized in terms of C-language and with structured and easily expandable characteristics. Also the controller is designed to possess diagnostic capability including self-diagnosis of processor module. The developed supervisory control has been shown to be very useful via a high speed automatic assembly system with vision capability.

  • PDF