學術出版;;Publications

Permanent URI for this communityhdl:11536/1

收集所有交通大學研究人員與學生個人或團體所發表之各項學術著作，涵蓋期刊論文、教師專書、學位論文等項。;;Collections of Publications of NCTU Researchers and Students Like Journal Papers and Thesis.

Browse

🏛️國立陽明交通大學機構典藏

Search Results

Now showing 1 - 10 of 55

Step-by-Step Assembled Enzyme-Polymer-Carbon Nanotubes for Solution-Processed Bioreactive Composites
(2019-07-01)
Lin, Hsiu-Pen
;
Akimoto, Jun
;
Li, Yaw-Kuen
;
Ito, Yoshihiro
;
Kawamoto, Masuki
Protein-conjugated single-walled carbon nano tubes (SWCNTs) have received much attention for their diverse applications in molecular biology. Intrinsically water insoluble SWCNTs avoid conjugation with proteins, which leads to limited availability of biomolecule nanocarbon composites. Because protein functions are directly affected by assembled structures, the synthesis of heterogeneous composites with bioreactive responses is a great challenge. We demonstrate that step-by-step assembled enzyme/polymer/SWCNTs are obtained by using noncovalent-bonding methodologies in aqueous media. A multifunctional polymer containing aromatic, cationic, and redox-active units allows for a direct aqueous dispersion of SWCNTs through pi interactions and a subsequent charge attraction to the enzyme, which yields the ternary composites. The resulting composites show bioreactive responses in enzyme-conjugated SWCNT networks. The solution-processed glucose oxidase (GO(x))/polymer/SWCNT composite displays a high current density of 1420 mu A cm(-2) by enzymatic oxidation of glucose. Only 2.4 mu g of GO(x) is shown to be necessary for the enzymatic reaction with a sensitivity of 72 mu A mM(-1) cm(-2). This high sensitivity results from the assembled structure through noncovalent-bonding interactions. We demonstrate that the bioreactive composite allows energy conversion from a glucose-including beverage (cola) to electricity. Lactate oxidase-driven bioreactivity also takes place on the structurally organized composite. This step-by-step methodology would be beneficial for enzyme-assisted energy conversion nanocomposites.
Preparation of polyhedral oligomeric silsesquioxane-containing block copolymer with well-controlled stereoregularity
(1970-01-01)
Tsai, Sung-Yu
;
Kuretani, Satoshi
;
Manabe, Kei
;
Terao, Toshiki
;
Komamura, Takahiro
Preparation of functional domains with a spacing of 10 nm is a benchmark set to fabricate next-generation electronic devices. Organic-inorganic block copolymers form well-ordered microphase separations with very small domain sizes. The design and preparation of a novel block copolymer consisting of syndiotactic polymethyl methacrylate (st-PMMA) and polyhedral oligomeric silsesquioxane (POSS)-functionalized polymethacrylate, designated as st-PMMA-b-PMAPOSS, which can recognize functional molecules, are reported. The st-PMMA segments form a helical structure and encapsulate C-60 in the helical nanocavity, leading to the formation of an inclusion complex. Although the ordering of the domains is not high, C-60 domains that are in a quasi-equilibrium state, with about 10-nm domain spacings, are generated using st-PMMA-b-PMAPOSS that can recognize functional molecules. (c) 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019
On-Surface Evolution of meso-Isomerism in Two-Dimensional Supramolecular Assemblies
(2019-07-08)
Park, Juyeon
;
Kim, Ju-Hyung
;
Bak, Sunmi
;
Tahara, Kazukuni
;
Jung, Jaehoon
Chiral structures created through the adsorption of molecules onto achiral surfaces play pivotal roles in many fields of science and engineering. Here, we present a systematic study of a novel chiral phenomenon on a surface in terms of organizational chirality, that is, meso-isomerism, through coverage-driven hierarchical polymorphic transitions of supramolecular assemblies of highly symmetric pi-conjugated molecules. Four coverage-dependent phases of dehydrobenzo[12]annulene were uniformly fabricated on Ag(111), exhibiting unique chiral characteristics from the single-molecule level to two-dimensional supramolecular assemblies. All coverage-driven phase transitions stem from adsorption-induced pseudo-diastereomerism, and our observation of a lemniscate-type (infinity) supramolecular configuration clearly reveals a drastic chiral phase transition from an enantiomeric chiral domain to a meso-isomeric achiral domain. These findings provide new insights into controlling two-dimensional chiral architectures on surfaces.
Reversing the Handedness of Self-Assembled Porous Molecular Networks through the Number of Identical Chiral Centres
(2019-06-03)
Tahara, Kazukuni
;
Noguchi, Aya
;
Nakayama, Ruri
;
Ghijsens, Elke
;
De Feyter, Steven
Scanning tunnelling microscope observations at the 1-phenyloctane/graphite interface reveal how chiral structural information at the molecular level is transferred and expressed structurally at the 2D supramolecular level for a porous system. The chirality of self-assembled molecular networks formed by chiral dehydrobenzo[12]annulene (cDBA) derivatives having three chiral chains and three achiral chains, alternatingly, is compared with those of cDBAs having six chiral chains reported previously. While for all cDBAs homochiral surfaces are formed, their handedness is not simply a reflection of the absolute configuration of the stereogenic centres. Both the number of stereogenic centres as well as the length of the achiral chains determine the supramolecular handedness, providing a deep insight into the supramolecular chirality induction mechanisms at play. Moreover, these cDBAs act to induce chirality in porous networks formed by achiral DBAs.
Impacts of structural asymmetry on the magnetic response of excitons and biexcitons in single self-assembled In(Ga)As quantum rings
(2009-08-01)
Lin, Ta-Chun
;
Lin, Chia-Hsien
;
Ling, Hong-Shi
;
Fu, Ying-Jhe
;
Chang, Wen-Hao
The diamagnetic shifts of neutral excitons and biexcitons confined in single self-assembled In(Ga)As/GaAs quantum rings are investigated. Unlike quantum dots, quantum rings reveal a considerably large biexciton diamagnetic shift, about two times larger than that of single excitons. Based on model calculations, we found that the inherent structural asymmetry and imperfection, combined with the interparticle Coulomb interactions, is the fundamental cause of the more extended biexciton wave function in the quantum rings. The exciton wave function tends to be localized in one of the potential valleys induced by structural imperfections of the quantum ring due to the strong localization of hole and the electron-hole Coulomb attraction, resembling the behavior in single dots. Our results suggest that the phase coherence of neutral excitons in quantum rings will be smeared out by such wave function localizations.
Self-Assembled Ferroelectric Nanoarray
(2019-01-16)
Jiang, Jie
;
Yang, Qiong
;
Zhang, Yi
;
Li, Xiao-Yu
;
Shao, Pao-Wen
Self-assembled heteroepitaxial nanostructures have played an important role for miniaturization of electronic devices, e.g., the ultrahigh density ferroelectric memories, and cause for great concern. Our first principle calculations predict that the materials with low formation energy of the interface (E-f) tend to form matrix structure in self-assembled heteroepitaxial nanostructures, whereas those with high E-f form nanopillars. Under the guidance of the theoretical modeling, perovskite BiFeO3 (BFO) nanopillars are swimmingly grown into CeO2 matrix on single-crystal (001)-SrTiO3 (STO) substrates by pulsed laser deposition, where CeO2 has a lower formation energy of the interface (E-f) than BFO. This work provides a good paradigm for controlling self-ssembled nanostructures as well as the application of self-assembled ferroelectric nanoscale memory.
Characteristics of emission polarization in a-plane nanorods embedded with InGaN/GaN multiple quantum wells
(2010-09-15)
Li, J. C.
;
Lu, T. C.
;
Huang, H. M.
;
Chan, W. W.
;
Kuo, H. C.
Nonpolar (a-plane) GaN nanorod arrays with embedded In(x)Ga(1-x)N/GaN (x=0.09, 0.14, 0.24, and 0.30) multiple quantum wells (MQWs) grown on r-plane sapphire have been fabricated successfully by self-assembled Ni nanomasks and subsequent inductively coupled plasma reactive-ion etching. After nanorod fabrications, the polarization ratio of the emission from MQWs with lower indium composition (x=0.09 and 0.14) slightly decreases but apparently increases by at most 79% for the samples with higher indium composition (x=0.24 and 0.30). Competition between the effect of multiple scattering, strain relaxation and reduction in localized centers, expected in a-plane MQW samples, are attributed to the variations in the polarization ratios after the nanorod formation. (c) 2010 American Institute of Physics. [doi:10.1063/1.3483239]
Self-Assembled Supramolecular Nanogels as a Safe and Effective Drug Delivery Vector for Cancer Therapy
(2017-05-01)
Cheng, Chih-Chia
;
Liang, Mei-Chih
;
Liao, Zhi-Sheng
;
Huang, Jyun-Jie
;
Lee, Duu-Jong
Simple construction and manipulation of low-molecular-weight supramolecular nanogels, based on the introduction of multiple hydrogen bonding interactions, with the desired physical properties to achieve effective and safe delivery of drugs for cancer therapy remain highly challenging. Herein, a novel supramolecular oligomer cytosine (Cy)-polypropylene glycol containing self-complementary multiple hydrogen-bonded Cy moieties is developed, which undergoes spontaneous self-assembly to form nanosized particles in an aqueous environment. Phase transitions and scattering studies confirm that the supramolecular nanogels can be readily tailored to obtain the desired phase-transition temperature and temperature-induced release of the anticancer drug doxorubicin (DOX). The resulting nanogels exhibit an extremely high load carrying capacity (up to 24.8%) and drug-entrapment stability, making the loading processes highly efficient. Importantly, in vitro cytotoxicity assays indicate that DOX-loaded nanogels possess excellent biosafety for drug delivery applications under physiological conditions. When the environmental temperature is increased to 40 degrees C, DOX-loaded nanogels trigger rapid DOX release and exert cytotoxic effects, significantly reducing the dose required compared to free DOX. Given its simplicity, low cost, high reliability, and efficiency, this newly developed temperature-responsive nanocarrier has highly promising potential for controlled release drug delivery systems.
Blending Homopolymers for Controlling the Morphology Transitions of Block Copolymer Nanorods Confined in Cylindrical Nanopores
(2017-06-21)
Cheng, Ming-Hsiang
;
Hsu, Yu-Chen
;
Chang, Chun-Wei
;
Ko, Hao-Wen
;
Chung, Pei-Yun
The microphase separation of block copolymers in confined geometries has been widely investigated over the last few decades. The controllability and versatility of the confinement-induced morphologies, however, are still difficult to be achieved because of the limited experimental parameters in the process of fabricating the confined nanostructures. In this work, we study the morphology transitions of lamellae forming polystyrene-block-polydimethylsiloxane (PS-b-PDMS) nanorods confined in the nanopores of anodic aluminum oxide (AAO) templates. The nanorods are formed by solvent-assisted template wetting, and the morphologies are compared to those in the bulk state. By blending PS-b-PDMS with homopolystyrene (hPS), the morphologies of the nanorods can be controlled because of the changes of the effective volume fractions. Special morphology transitions from concentric lamellar morphology, to multihelical morphology, and finally to spherical-like morphology are observed by increasing the weight ratios of hPS. hPS with different molecular weights is also applied to investigate the effect of hPS on the morphologies of the PS-b-PDMS/hPS blend nanostructures. The unusual morphologies are further confirmed by a selective removal process, which also generates nanochannels for possible refilling with functional materials.
Glucosamine-Based Supramolecular Nanotubes for Human Mesenchymal Cell Therapy
(2018-05-02)
Talloj, Satish Kumar
;
Cheng, Bill
;
Weng, Jen-Po
;
Lin, Hsin-Chieh
;
材料科學與工程學系
Herein, we demonstrate an example of glucosamine-based supramolecular hydrogels that can be used for human mesenchymal cell therapy. We designed and synthesized a series of amino acid derivatives based on a strategy of capping D-glucosamine moiety at the C-terminus and fluorinated benzyl group at the N-terminus. From a systematic study on chemical structures, we discovered that the glucosamine-based supramolecular hydrogel [pentafluorobenzyl (PFB)-F-Glu] self-assembled with one-dimensional nanotubular structures at physiological pH. The self-assembly of a newly discovered PFB-F-Glu motif is attributed to the synergistic effect of pi-pi stacking and extensive intermolecular hydrogen bonding network in aqueous medium. Notably, PFB-F-Glu nanotubes are proven to be nontoxic to human mesenchymal stem cells (hMSCs) and have been shown to enhance hMSC proliferation while maintaining their pluripotency. Retaining of pluripotency capabilities provides potentially unlimited source of undifferentiated cells for the treatment of future cell therapies. Furthermore, hMSCs cultured on PFB-F-Glu are able to secrete paracrine factors that downregulate profibrotic gene expression in lipopolysaccharide-treated human skin fibroblasts, which demonstrates that PFB-F-Glu nanotubes have the potential to be used for wound healing applications. Overall, this article addresses the importance of chemical design to generate supramolecular biomaterials for stem cell therapy.

學術出版;;Publications

Browse

Filters

Settings

Sort By

Results per page

🏛️國立陽明交通大學機構典藏

Search Results