Browsing by Author "Chang, Po-Hsueh"

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A High-Sensitivity and Low-Power Theranostic Nanosystem for Cell SERS Imaging and Selectively Photothermal Therapy Using Anti-EGFR-Conjugated Reduced Graphene Oxide/Mesoporous Silica/AuNPs Nanosheets
(2016-03-16)
Chen, Yu-Wei
;
Liu, Ting-Yu
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Chen, Po-Jung
;
Chang, Po-Hsueh
;
Chen, San-Yuan
A high-sensitivity and low-power theranostic nanosystem that combines with synergistic photothermal therapy and surface-enhanced Raman scattering (SERS) mapping is constructed by mesoporous silica self-assembly on the reduced graphene oxide (rGO) nanosheets with nanogap-aligned gold nanoparticles (AuNPs) encapsulated and arranged inside the nanochannels of the mesoporous silica layer. Rhodamine 6G (R6G) as a Raman reporter is then encapsulated into the nanochannels and anti-epidermal growth factor receptor (EGFR) is conjugated on the nanocomposite surface, defined as anti-EGFR-PEG-rGO@CPSS-Au-R6G, where PEG is polyethylene glycol and CPSS is carbon porous silica nanosheets. SERS spectra results show that rGO@CPSS-Au-R6G enhances 5 x 10(6) magnification of the Raman signals and thus can be applied in the noninvasive cell tracking. Furthermore, it displays high sensitivity (detection limits: 10(-8) M R6G solution) due to the "hot spots" effects by the arrangements of AuNPs in the nanochannels of mesoporous silica. The highly selective targeting of overexpressing EGFR lung cancer cells (A549) is observed in the anti-EGFR-PEG-rGO@CPSS-Au-R6G, in contrast to normal cells (MRC-5). High photothermal therapy efficiency with a low power density (0.5 W cm(-2)) of near-infrared laser can be achieved because of the synergistic effect by conjugated AuNPs and rGO nanosheets. These results demonstrate that the anti-EGFR-PEG-rGO@CPSS-Au-R6G is an excellent new theranostic nanosystem with cell targeting, cell tracking, and photothermal therapy capabilities.
A theranostic nrGO@MSN-ION nanocarrier developed to enhance the combination effect of sonodynamic therapy and ultrasound hyperthermia for treating tumor
(2016)
Chen, Yu-Wei
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Liu, Tse-Ying
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Chang, Po-Hsueh
;
Hsu, Po-Hung
;
Liu, Hao-Li
Sonodynamic therapy (SDT), which induces activation of sonosensitizers in cancer cells through ultrasound irradiation, has emerged as an alternative and promising noninvasive therapeutic approach to kill both superficial and deep parts of tumors. In this study, mesoporous silica (MSN) grown on reduced graphene oxide nanosheet (nrGO) capped with Rose Bengal (RB)-PEG-conjugated iron-oxide nanoparticles (IONs), nrGO@MSN-ION-PEG-RB, was strategically designed to have targeted functionality and therapeutic efficacy under magnetic guiding and focused ultrasound (FUS) irradiation, respectively. The singlet oxygen produced by ultrasound-activated RB and the ultrasound-induced heating effect was enhanced by rGO and IONs, which improved the cytotoxic effect in cancer cells. In an animal experiment, we demonstrated that the combination of sonodynamic/hyperthermia therapy with magnetic guidance using this nanocomposite therapeutic agent can produce remarkable efficacious therapy in tumor growth inhibition. Furthermore, the combination effect induced by FUS irradiation produces significant damage to both superficial and deep parts of the targeted tumor.
Ca-Rich Ca-Al-Oxide, High-Temperature-Stable Sorbents Prepared from Hydrotalcite Precursors: Synthesis, Characterization, and CO2 Capture Capacity
(2011)
Chang, Po-Hsueh
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Chang, Yen-Po
;
Chen, San-Yuan
;
Yu, Ching-Tsung
;
Chyou, Yau-Pin
We present the design and synthesis of Ca-rich Ca-Al-O oxides, with Ca(2+)/Al(3+) ratios of 1:1, 3:1, 5:1, and 7:1, which were prepared by hydrothermal decomposition of coprecipitated hydrotalcite-like Ca-Al-CO(3) precursors, for high-temperature CO(2) adsorption at 500-700 degrees C. In situ X-ray diffraction measurements indicate that the coprecipitated, Ca-rich, hydrotalcite-like powders with Ca(2+)/Al(3+) ratios of 5:1 and 7:1 contained Ca(OH)(2) and layered double hydroxide (LDH) phases. Upon annealing, LDH was first destroyed at approximately 200 degrees C to form an amorphous matrix, and then at 450-550 degrees C, the Ca(OH)(2) phase was converted into a CaO matrix with incorporated Al(3+) to form a homogeneous solid solution without a disrupted lattice structure. CaO nanocrystals were grown by thermal treatment of the weakly crystalline Ca-Al-O oxide matrix. Thermogravimetric analysis indicates that a CO(2) adsorption capacity of approximately 51 wt.% can be obtained from Ca-rich Ca-Al-O oxides prepared by calcination of 7:1 Ca-Al-CO(3) LDH phases at 600-700 degrees C. Furthermore, a relatively high CO(2) capture capability can be achieved, even with gas flows containing very low CO(2) concentrations (CO(2)/N(2)=10%). Approximately 95.6% of the initial CO(2) adsorption capacity of the adsorbent is retained after 30 cycles of carbonationcalcination. TEM analysis indicates that carbonation-promoted CaCO(3) formation in the Ca-Al-O oxide matrix at 600 degrees C, but a subsequent desorption in N(2) at 700 degrees C, caused the formation CaO nanocrystals of approximately 10 nm. The CaO nanocrystals are widely distributed in the weakly crystalline Ca-Al-O oxide matrix and are present during the carbonationcalcination cycles. This demonstrates that Ca-Al-O sorbents that developed through the synthesis and calcination of Ca-rich Ca-Al LDH phases are suitable for long-term cyclic operation in severe temperature environments.
CO2 Sorbents with Scaffold-like CaAl Layered Double Hydroxides as Precursors for CO2 Capture at High Temperatures
(2013-06-01)
Chang, Po-Hsueh
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Lee, Tai-Jung
;
Chang, Yen-Po
;
Chen, San-Yuan
;
材料科學與工程學系
A highly stable high-temperature CO2 sorbent consisting of scaffold-like Ca-rich oxides (CaAlO) with rapid absorption kinetics and a high capacity is described. The Ca-rich oxides were prepared by annealing CaAlNO3 layered double hydroxide (LDH) precursors through a sol-gel process with Al(OiP)3 and Ca(NO3)2 with Ca2+/Al3+ ratios of 1:1, 2:1, 4:1, and 7:1. XRD indicated that only LDH powders were formed for Ca2+/Al3+ ratios of 2:1. However, both LDH and Ca(OH)2 phases were produced at higher ratios. Both TEM and SEM observations indicated that the CaAlNO3 LDHs displayed a scaffold-like porous structure morphology rather than platelet-like particles. Upon annealing at 600 degrees C, a highly stable porous network structure of the CaO-based CaAlO mixed oxide (CAMO), composed of CaO and Ca12Al14O33, was still present. The CAMO exhibited high specific surface areas (up to 191m2g-1) and a pore size distribution of 3-6nm, which allowed rapid diffusion of CO2 into the interior of the material, inducing fast carbonation/calcination and enhancing the sintering-resistant nature over multiple carbonation/calcination cycles for CO2 absorption at 700 degrees C. Thermogravimetric analysis results indicated that a CO2 capture capacity of approximately 49wt% could be obtained with rapid absorption from the porous 7:1 CAMO sorbents by carbonation at 700 degrees C for 5min. Also, 94-98% of the initial CO2 capture capability was retained after 50cycles of multiple carbonation/calcination tests. Therefore, the CAMO framework is a good isolator for preventing the aggregation of CaO particles, and it is suitable for long-term cyclic operation in high-temperature environments.
Morphological and structural evolution of mesoporous calcium aluminate nanocomposites by microwave-assisted synthesis
(2014-01-01)
Chang, Yen-Po
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Chang, Po-Hsueh
;
Lee, Yuan-Tse
;
Lee, Tai-Jung
;
Lai, Yen-Ho
Novel special dual-structure calcium aluminate nanocomposites consisting of mesoporous Ca-containing Al2O3 nanonetworks with Ca12Al14O33 polycrystalline nanorods have been successfully synthesized using the microwave-hydrothermal (M-H) process in an alcohol solution consisting of calcium nitrate and mesoporous alumina, followed by calcination at a lower temperature (e.g., less than 600 degrees C). The mesoporous Ca-containing aluminate nanocomposites possessed a specific surface area of 51 m(2) g(-1) and a broad pore size distribution of 4-12 nm in diameter, as observed from N-2 adsorption/desorption measurements. The results showed that highly dispersed Ca12Al14O33 nanorods grown on the mesoporous nanostructure were obtained by varying the molar ratio of Ca/Al or by controlling microwave heating time, as characterized by scanning electron microscopy (SEM), transmission electron microscopy/electronic energy loss spectroscopy (TEM/EELS) and powder X-ray diffraction (PXRD). The Ca12Al14O33 nanorods with diameters of 50-100 nm and lengths of 200-400 nm were grown in and on the one-dimensional mesochannels. A formation mechanism of the mesoporous Ca-containing aluminate nanocomposites involving amorphous mesoporous hydrated-Al2O3 was also proposed. (C) 2013 Elsevier Inc. All rights reserved.
Multi-Metals CaMgAl Metal-Organic Framework as CaO-based Sorbent to Achieve Highly CO2 Capture Capacity and Cyclic Performance
(2020-05-01)
Wu, Szu-Chen
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Chang, Po-Hsueh
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Lin, Chieh-Yen
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Peng, Cheng-Hsiung
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材料科學與工程學系
In this study, Ca-based multi-metals metal-organic framework (CaMgAl-MOF) has been designed as precursor material for carbon dioxide (CO2) capture to enhance the CO2 capture capacity and stability during multiple carbonation-calcination cycles. The CaMgAl-MOFs were constructed from self-assembly of metal ions and organic ligands through hydrothermal process to make metal ions uniformly distributed through the whole structure. Upon heat treatment at 600 degrees C, the Ca-based multi-metals CaMgAl-MOF would gradually transform to CaO and MgO nanoparticles along with the amorphous aluminum oxide distributed in the CaO matrix. XRD, Fourier transform infrared (FTIR), and SEM were used to identify the structure and characterize the morphology. The CO2 capture capacity and multiple carbonation-calcination cyclic tests of calcined Ca-based metal-organic framework (MOF) (attached with O and indicated as Ca-MOF-O) were performed by thermal gravimetric analysis (TGA). The single metal component calcined Ca-MOF sorbent have the highest CO2 capture capacity up to 72 wt.%, but a lower stability of 61% due to severe particle aggregation. In contrast, a higher Ca-rich MOF oxide sorbent with tailoring the Mg/Al ratios, Ca0.97Mg0.025Al0.005-MOF-O, showed the best performance, not only having the high stability of similar to 97%, but also maintaining the highest capacity of 71 wt.%. The concept of using Ca-based MOF materials combined with mixed-metal ions for CO2 capture showed a potential route for achieving efficient multiple carbonation-calcination CO2 cycles.
Synthesis, characterization and high temperature CO2 capture capacity of nanoscale Ca-based layered double hydroxides via reverse microemulsion
(2014-02-15)
Chang, Po-Hsueh
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Chang, Yen-Po
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Lai, Yen-Ho
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Chen, San-Yuan
;
Yu, Ching-Tsung
In this study, we report a reverse microemulsion method to prepare stable homogeneous suspensions containing dispersed Ca-Al layered double hydroxide (LDH) nanoparticles. By changing the concentration, reaction time and temperature, the nano-particles with different structural morphology was developed from amorphous aggregation to platelet, regular hexagon and hydrangea-like hierarchical structure. The crystallization and growth of Ca-Al LDH nanoparticles were involved with a nucleation and growth process under nonaqueous polar solvent/surfactant system. After calcination at 700 degrees C, the calcined nano-sized Cal-Al LDH powders synthesized from the reverse microemulsion display remarkable CO2 capture behavior at 600 degrees C, which is strongly dependent on the reaction conditions (concentration, time and temperature). The calcined powder synthesized at 80 degrees C exhibits a faster rate of CO2 absorption and higher CO2 capture capacity of 44 wt% CO2 without apparent degradation under multiple cycles of carbonation-calcination. (C) 2013 Elsevier B. V. All rights reserved.
Synthesis, Characterization, and CO2 Adsorptive Behavior of Mesoporous AlOOH-Supported Layered Hydroxides
(2012)
Chang, Yen-Po
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Chen, Yu-Chun
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Chang, Po-Hsueh
;
Chen, San-Yuan
;
材料科學與工程學系
A novel CO2 solid sorbent was prepared by synthesizing and modifying AlOOH-supported CaAl layered double hydroxides (CaAl LDHs), which were prepared by using mesoporous alumina (?-Al2O3) and calcium chloride (CaCl2) in a hydrothermal urea reaction. The nanostructured CaAl LDHs with nanosized platelets (330 nm) formed and dispersed inside the crystalline framework of mesoporous AlOOH (boehmite). By calcination of AlOOH-supported LDHs at 700 degrees C, the mesoporous CaAl metal oxides exhibited ordered hexagonal mesoporous arrays or uniform nanotubes with a large surface area of 273 m2?g-1, a narrow pore size distribution of 6.2 nm, and highly crystalline frameworks. The crystal structure of the calcined mesoporous CaAl metal oxides was multiphasic, consisting of CaO/Ca(OH)2, Al2O3, and CaAlO mixed oxides. The mesoporous metal oxides were used as a solid sorbent for CO2 adsorption at high temperatures and displayed a maximum CO2 capture capacity (approximate to 45 wt?%) of the sorbent at 650 degrees C. Furthermore, it was demonstrated that the mesoporous CaAl oxides showed a more rapid adsorption rate (for 12 min) and longer cycle life (weight change retention: 80?% for 30 cycles) of the sorbent because of the greater surface area and increased number of activated sites in the mesostructures. A simple model for the formation mechanism of mesoporous metal oxides is tentatively proposed to account for the synergetic effect of CaAl LDHs on the adsorption of CO2 at high temperature.