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1.
J Nanosci Nanotechnol ; 17(4): 2563-566, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29658688

RESUMO

Polymer electrolyte membrane (PEM) confirms the life span of vanadium redox flow battery (VRFB). Products from Dupont, Nafion membrane, is mainly used for PEM in VRFB. However, permeation of vanadium ion occurs because of Nafion's high permeability. Therefore, the efficiency of VRFB decreases and the prices becomes higher, which hinders VRFB's commercialization. In order to solve this problem, poly(phenylene oxide) (PPO) is sulfonated for the preparation of low-priced hydrocarbon polymer electrolyte membrane. sPPO membrane is characterized by fundamental properties and VRFB cell test.

2.
J Nanosci Nanotechnol ; 15(1): 484-7, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26328387

RESUMO

Microbial fuel cells (MFCs) are bio-electrochemical system that can convert biomass spontaneously into electricity through the metabolic activity of microorganisms. We constructed MFCs of polypyrrole (PPy) coated carbon nanotube (CNT) composite as an electrode material and Shewanella oneidensis as the biocatalyst to increase power density. The PPy-coated CNT were synthesized by the in-situ chemical polymerization of pyrrole on CNT, and the electrochemical properties and performance of the modified electrode as an anode in MFC were then investigated. Treatment with 0.1 wt% Ge-132 on the acid-treated MWNTs helped to form better PPy-MWNT composite. The PPy-CNT/CF anode showed a noteworthy 38% power production improvement when compared to plain CF anode. The PPy-CNT composite could be a very efficient and promising electrode material for electricity generation of MFC.


Assuntos
Fontes de Energia Bioelétrica , Nanotubos de Carbono/química , Polímeros/química , Pirróis/química , Eletrodos , Germânio , Compostos Organometálicos , Propionatos
3.
J Nanosci Nanotechnol ; 15(1): 665-8, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26328422

RESUMO

One-pot Si-Si/Si-O dehydrocoupling of hydrosilanes with alcohols (1:1.5 mole ratio), promoted by a mixture of AgNO3-H2PtCl6 (150/1 mole ratio) readily gave poly(alkoxysilane)s in good yield (62-91%). The addition of small amount of platinum complex to form nanoparticles facilitated the silicon polymer formation when compared to the reaction rate with AgNO3 alone. The primary/secondary hydrosilanes [p-X-C6H4SiH3 (X = H, CH3, OCH3, F), PhCH2SiH3, and (PhSiH2)2] and alcohols [MeOH, EtOH, (i)PrOH, PhOH, and CF3(CF2)2CH2OH] were used for the reaction. The weight average molecular weight and polydispersity of the poly(alkoxysilane)s were in the range of 1,690-7,100 Dalton and 1.44-3.49, respectively. The reaction of phenylsilane with ethanol (1:3 mole ratio) using the Ag-Pt complexes produced triethoxyphenylsilane only, as expected. The reaction of phenylsilane with Ge-132 produced an insoluble cross-linked gel.


Assuntos
Técnicas de Química Sintética/métodos , Nanopartículas/química , Platina/química , Silanos/química , Nitrato de Prata/química , Álcoois , Germânio , Peso Molecular , Compostos Organometálicos , Compostos de Platina , Polímeros/química , Propionatos
4.
J Nanosci Nanotechnol ; 14(8): 6438-41, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25936133

RESUMO

Codehydrocoupling (using Red-Al) followed by borane/phosphine-capping (with Ph2BCl and Ph2PCl) of 1,1-dihydrotetraphenylsilole (1) and 1,1-dihydrotetraphenylgermole (2) (9:1 mole ratio) gave electroluminescent poly(silole-co-germole)s containing borane/phosphine-ends (3, 4) in high yield. The borane-terminated copolymer 3 emits at 522 nm and are electroluminescent at 521 nm. The fluorescence quantum yield of 3 in toluene is (1.60±0.30) x 10(-2). The phosphine-terminated copolymer 4 emits at 520 nm and are electroluminescent at 520 nm. The fluorescence quantum yield of 4 in toluene is (1.60±0.20) x 10(-2). 3 and 4 were then mixed in 1:1 ratio. The emission color of 3/4 mixture is green and the maximum brightness of the device is 2,760 cd/m2 with a luminous efficiency of 0.67 lm/W. The borane/phosphine end groups in the 1:1 mixture of 3 and 4 exhibited no appreciable effect on the luminescent properties in spite of possible B-P dative bonding. Ge-132 helped to increase the B-P dative bonding. The electroluminescent copolymers 3 and 4 are good candidates for PLED (polymer light-emitting diode) fabrication.


Assuntos
Boranos/química , Luz , Fosfinas/química , Polímeros/química , Luminescência
5.
J Nanosci Nanotechnol ; 13(6): 4158-61, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23862465

RESUMO

Anodic material is usually a limiting factor in power generation in microbial fuel cell (MFC). A meditatorless two-chambered MFC was constructed using new type of carbon nanotube (CNT)-based electrode architecture by layer-by-layer (LBL) self-assembly to increase power density. Multi-walled carbon nanotube (MWNT) and polyeletrolyte polyethyleneimine (PEI) were employed to modify carbon paper (CP) electrode utilizing a LBL self-assembly technique, and the electrochemical properties and performance of the modified electrode as an anode in MFC were investigated. The CNT-based LBL self-assembled electrode showed a better electrochemical performance than that of unmodified CP electrode. The self-assembled MWNT/PEI onto CP produced the maximum power density of 480 mW/m2, which was 48% larger than that of the plain CP anode. The CNT-based LBL self-assembled electrode therefore offers good prospects for application in MFCs.


Assuntos
Fontes de Energia Bioelétrica , Eletrodos , Nanotubos de Carbono , Microscopia Eletrônica de Varredura
6.
J Nanosci Nanotechnol ; 13(1): 638-42, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23646789

RESUMO

The generation of silver nanoparticle/bis(o-phenolpropyl)silicone composites have been facilitated by the addition of sodium tetrachloroaurate or gold(Ill) chloride (< 1 wt% of NaAuCl4 or AuCl3) to the reaction of silver nitrate (AgNO3) with bis(o-phenolpropyl)silicone [BPPS, (o-phenolpropyl)2(SiMe2O)n, n = 2,3,8,236]. TEM and FE-SEM data showed that the silver nanoparticles having the size of < 20 nm are well dispersed throughout the BPPS silicone matrix in the composites. XRD patterns are consistent with those for polycrystalline silver. The size of silver nanoparticles augmented with increasing the relative molar concentration of AgNO3 added with respect to BPPS. The addition of gold complexes (1-3 wt%) did not affect the size distribution of silver nanoparticles appreciably. In the absence of BPPS, the macroscopic precipitation of silver by agglomeration, indicating that BPPS is necessary to stabilize the silver nanoparticles surrounded by coordination.


Assuntos
Cristalização/métodos , Ouro/química , Nanopartículas Metálicas/química , Nanopartículas Metálicas/ultraestrutura , Silicones/química , Prata/química , Catálise , Teste de Materiais , Conformação Molecular , Tamanho da Partícula , Propriedades de Superfície
7.
J Nanosci Nanotechnol ; 13(1): 702-5, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23646801

RESUMO

Combinative one-pot Si-Si/Si-O dehydrocoupling of hydrosilanes with alcohols (1:1.5 mole ratio), mediated by a mixture of AgNO3-AuCl3 (100/1 mole ratio) rapidly produced poly(alkoxysilane)s in reasonably high yield. The addition of small amount of gold complex to the reaction mixture effectively accelerated the coupling reaction compared to the reaction rate with AgNO3 alone. The hydrosilanes include p-X-C6H4SiH3 (X = H, CH3, OCH3, F), PhCH2SiH3, and (PhSiH2)2. The alcohols include MeOH, EtOH, iPrOH, PhOH, and CF3(CF2)2CH2OH. The weight average molecular weight and polydispersity of the poly(alkoxysilane)s were in the range of 1,600-8,000 Dalton and 1.4-3.5, respectively. The dehydrocoupling reactions of phenylsilane with ethanol (1:3 mole ratio) in the presence of the Ag-Au complexes gave only triethoxyphenylsilane.


Assuntos
Álcoois/química , Cristalização/métodos , Ouro/química , Nanoestruturas/química , Nanoestruturas/ultraestrutura , Silanos/química , Prata/química , Catálise , Substâncias Macromoleculares/química , Teste de Materiais , Conformação Molecular , Tamanho da Partícula , Propriedades de Superfície
8.
J Nanosci Nanotechnol ; 12(5): 4252-5, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22852384

RESUMO

A microbial fuel cell (MFC) is a device that converts chemical energy to electrical energy using the catalytic reaction of microorganisms. We investigated the performance of mediator-less MFC with carbon nanotubes (CNTs)/graphite felt composite electrodes. The addition of CNTs to a graphite felt electrode increases the specific surface area of the electrode and enhances the charge transfer capability so as to cause considerable improvement of the electrochemical activity for the anode reaction in a MFC. The performance of the MFC using CNTs/graphite felt electrode has been compared against a plain graphite felt electrode based MFC. A CNTs/graphite felt electrode showed as high as 15% increase in the power density (252 mW/m2) compared to graphite felt electrode (214 mW/m2). The CNTs/graphite felt anode therefore offers good prospects for application in MFCs.


Assuntos
Fontes de Energia Bioelétrica , Reatores Biológicos , Eletrodos , Nanotubos de Carbono/química , Escherichia coli/química , Escherichia coli/metabolismo
9.
J Nanosci Nanotechnol ; 11(2): 1364-7, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21456189

RESUMO

The performance of carbon nanotubes composite-modified carbon cloth electrodes in two-chambered microbial fuel cell (MFC) was investigated. The electrode modified with polyacrylonitrile-carbon nanotubes (PAN-CNTs) composite showed better electrochemical performance than that of plain carbon cloth. The MFC with the composite-modified anode containing 5 mg/cm2 PAN-CNTs exhibited a maximum power density of 480 mW/m2.


Assuntos
Resinas Acrílicas , Fontes de Energia Bioelétrica , Nanocompostos , Nanotubos de Carbono , Resinas Acrílicas/química , Eletrodos , Etanol , Microscopia Eletrônica de Varredura , Nanocompostos/química , Nanocompostos/ultraestrutura , Nanotecnologia , Nanotubos de Carbono/ultraestrutura , Têxteis
10.
J Nanosci Nanotechnol ; 11(5): 4620-3, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21780509

RESUMO

Codehydrocoupling (with various inorganic hydrides) followed by stannane-capping (with Ph2SnHCI) of 1,1-dihydrotetraphenylsilole (1) and 1,1-dihydrotetraphenylgermole (2) (9:1 mol ratio) produces electroluminescent stannane-terminated poly(silole-co-germole)s (3) in high yield. The polymerization yield and molecular weight with Selectride increase in the order L-Selectride < N-Selectride < K-Selectride. The molecular weights increase in the order L-Selectride < Red-Al < N-Selectride < K-Selectride < Super-Hydride. The copolymer 3, a good candidate for PLED fabrication, emits at 523 nm and are electroluminescent at 521 nm. The fluorescence quantum yield of 3 in toluene is (1.61 +/- 0.29) x 10(-2). The emission color is green. The maximum brightness of the device is 3,750 cd/m2 with a luminous power efficiency of 0.67 Im/W.

11.
J Nanosci Nanotechnol ; 11(2): 1593-6, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21456244

RESUMO

Silver nanoparticle/bis(o-phenolpropyl)silicone composites have been synthesized by the reduction of silver nitrate with bis(o-phenolpropyl)silicone BPPS [(o-phenolpropyl)2(SiMe2O)n, n = 2, 3, 8, 236]. TEM and FE-SEM data clearly show that the silver nanoparticles with the size of < 20 nm are well dispersed throughout the BPPS matrix in the composites. XRD patterns are consistent with those for multicrystalline silver. The size of silver nanoparticles increased with increasing the relative molar concentration of silver salts added. It was found that in the absence of BPPS, most of the silver nanoparticles undergo macroscopic precipitation by agglomeration, indicating that BPPS is essential to stabilize the silver nanoparticles.

12.
J Nanosci Nanotechnol ; 11(2): 1722-5, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21456276

RESUMO

Si-Si/Si-O dehydrocoupling of hydrosilanes with alcohols (1:1.5 mole ratio), catalyzed by AgNO3 which converted to Ag(0) colloidal nanoparticles, gave poly(alkoxysilane)s in one-pot in moderate to high yield. The hydrosilanes include p-X-C6H4SiH3 (X = H, CH3, OCH3, F), PhCH2SiH3, and (PhSiH2)2. The alcohols include MeOH, EtOH, (i)PrOH, PhOH, and CF3(CF2)2CH2OH. The weight average molecular weight and polydispersity of the poly(alkoxysilane)s were in the range of 1,600 approximately 8,000 Dalton and 1.4 approximately 3.5. The dehydrocoupling reactions of phenylsilane with ethanol (1:3 mole ratio) in the presence of the silver nanocolloid catalyst produced only triethoxyphenylsilane as product.

13.
J Nanosci Nanotechnol ; 10(5): 3271-4, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20358937

RESUMO

A microbial fuel cell (MFC) is an electrochemical device that can directly convert the chemical energy stored in organic matter into electricity using microorganisms as a biocatalyst. The performance of multiwalled carbon nanotube (MWCNT)/polyarcylonitrile (PAN) composite modified carbon paper electrodes in two-chambered MFC was investigated. The electrocatalytic behaviors of the MWCNT/PAN composite anode were examined by using cyclic voltammetry. The MWCNT/PAN composite anode showed better electrochemical performance than that of PAN anode without MWCNT and the electricity generation of the MFC increased along with the increase of the MWCNT composite loading. The 5 wt% MWCNT/PAN composite anode has the highest electrochemical activity and its maximum power density is found to be 45 mW/m2 with acetate.


Assuntos
Fenômenos Fisiológicos Bacterianos , Fontes de Energia Bioelétrica/microbiologia , Eletrodos , Nanotecnologia/instrumentação , Nanotubos de Carbono/química , Nitrilas/química , Cristalização/métodos , Substâncias Macromoleculares/química , Teste de Materiais , Conformação Molecular , Nanotubos de Carbono/ultraestrutura , Tamanho da Partícula , Propriedades de Superfície
14.
J Nanosci Nanotechnol ; 10(5): 3425-9, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20358971

RESUMO

Mesoporous silica spheres (SBA-15) have been obtained via a two-step synthesis process by using a triblock copolymer as a template in combination with a co-surfactant and co-solvent. Multi-amine-grafted mesoporous silicas were prepared by attaching 3-aminopropyl triethoxysilane, N-2(-aminoethyl)-3-aminopropyltrimethoxysilane and (3-trimethoxysilylpropyl)diethylenetriamine via a post-synthetic method. The proteins used in adsorption experiments include Bovine Serum Albumin (BSA), Lysozyme (LYS) and Myoglobin (MYO). The protein adsorption properties such as equilibrium and kinetics were investigated. The results show that the original SBA-15 samples have the highest adsorption capacity for all proteins due to their largest pore size and internal surface area.


Assuntos
Aminas/química , Cristalização/métodos , Nanosferas/química , Nanosferas/ultraestrutura , Nanotecnologia/métodos , Proteínas/química , Dióxido de Silício/química , Adsorção , Substâncias Macromoleculares/química , Teste de Materiais , Conformação Molecular , Tamanho da Partícula , Ligação Proteica , Propriedades de Superfície
15.
J Nanosci Nanotechnol ; 10(5): 3467-72, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20358980

RESUMO

Based on morphology of SBA-15 particles, each has its own synthetic procedure and characteristics, resulting in different adsorption capacity as well as application in drug delivery system. This study focused on the synthesis mesoporous material SBA-15 with spherical morphology. The synthesized mesoporous silica SBA-15 were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), fourier transform infrared (FT-IR), and BET analysis. The release study of original and modified samples were carried out to assess application for controlled drug delivery system. The adsorbed proteins can be readily desorbed on amine-modified samples. Especially, the diamine-modified sample has the highest release amount for two proteins, Lysozyme (LYS) and Myoglobin (MYO).

16.
J Nanosci Nanotechnol ; 20(9): 5711-5715, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32331164

RESUMO

A microbial fuel cell (MFC) is bioelectrochemical system that enables the biochemical activities of bacteria to generate electricity. A composite membrane was prepared from polyvinylidene fluoride nanofiber coated with perfluorinated sulfuric acid ionomer (PVDF-PFSA) and evaluated as a replacement for the commercially available Nafion membrane, which is commonly used in MFC reactors. The power density obtained with the PVDF-PFSA composite membrane was higher than that obtained with the Nafion membrane in MFC reactors. The PVDF-PFSA composite membrane produced a maximum power density of 548 mW/m². Hence, the PVDF-PFSA composite reported here is a promising candidate for use as a proton exchange membrane in energy devices and water treatment systems.


Assuntos
Fontes de Energia Bioelétrica , Nanofibras , Eletricidade , Eletrodos , Polivinil , Ácidos Sulfúricos
17.
J Nanosci Nanotechnol ; 20(9): 5765-5770, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32331176

RESUMO

Sulfonated poly(phenylene) oxide (sPPO) polymer is coated in a dopamine hydrochloride solution to prepare a highly durable, low-price polymer membrane for vanadium redox flow batteries (VRFBs). The polydopamine (PDA) coating on the sPPO membrane is confirmed using SEM and EDX analysis. sPPO coated with PDA exhibits decreased proton conductivity due to high resistance. However, VO+2 reducibility tests shows that the chemical stability is improved due to the introduction of the PDA coating layer on the sPPO membrane, which has a chemical structure with poor durability in VO+2 solution under the operating conditions of a VRFB. These results show that this polymer electrolyte membrane based on PDA-coated sPPO is a candidate for application in the long-term operation of VRFBs.

18.
J Nanosci Nanotechnol ; 8(10): 5147-51, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19198409

RESUMO

Silica nanofibers were prepared by electrospinning method using PVP/P123 blend polymer solutions. Here, a triblock copolymer (Pluronic P123, EO20PO70EO20, M(av) = 5800) was used as the structure directing agent and polyvinyl pyrrolidone (PVP) as the fiber template. The samples were characterized by scanning electron microscopy (SEM), Fourier Transform Infrared (FT-IR), X-ray diffraction (XRD), TGA (thermal gravimetric analysis), and Brunauer-Emmett-Teller (BET). It was found that the silica nanofibers synthesized in this work had uniform pore structure with high surface area. An average fiber diameter, average pore diameter, and surface area were about 300 nm, 2.7 nm and 607 m2 g(-1). Adsorption equilibrium data of lysozyme on the synthesized silica nanofibers were correlated well with Langmuir equation.


Assuntos
Nanoestruturas , Polímeros/química , Dióxido de Silício/química , Adsorção , Microscopia Eletrônica de Varredura , Proteínas/química , Soluções , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
19.
J Nanosci Nanotechnol ; 8(10): 5152-7, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19198410

RESUMO

Since the discovery of ordered mesoporous silica M41S in 1992, a variety of ordered mesoporous materials have been synthesized by using the template technique. In this work, aminosilane-modified SBA-15 nanoparticles were prepared by incorporating various aminosilanes on original SBA-15 via post synthesis method. These aminosilanes were 3-aminopropyltriethoxysilane, N-2(-aminoethyl)-3-aminopropyl trimethoxysilane and (3-trimethoxysilylpropyl)diethylenetriamine. The synthesized nanoparticles were characterized by XRD, SEM, TEM and FT-IR. Adsorption and release studies of bovine serum albumin (BSA), lysozyme and myoglobin on SBA-15 samples were investigated. It was found that the synthesized SBA-15 nanoparicles can be successfully applied in drug delivery system.


Assuntos
Nanopartículas , Proteínas/química , Silanos/química , Dióxido de Silício/química , Adsorção , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão
20.
Int J Pharm ; 352(1-2): 317-23, 2008 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-18160236

RESUMO

The aim of this study was to prepare ciprofloxacin HCl (CIP)-encapsulated poly(dl-lactide-co-glycolide) (PLGA) copolymer nanoparticles and its antibacterial potential was evaluated with pathogenic bacteria, Escherichia coli (E. coli), in vitro and in vivo. CIP-encapsulated nanoparticles of PLGA were prepared by multiple emulsion solvent evaporation method. PLGA nanoparticles showed spherical shapes with particle sizes around 100-300 nm. Loading efficiency was lower than 50% (w/w) because of water-solubility properties of CIP. At drug release study, CIP showed initial burst effect for 12 h and then continuously released for 2 weeks. At in vitro antibacterial activity test, CIP-encapsulated nanoparticles showed relatively lower antibacterial activity compared to free CIP due to the sustained release characteristics of nanoparticles. However, CIP-encapsulated PLGA nanoparticles (doses: 25 mg CIP/kg of mice) effectively inhibited the growth of bacteria due to the sustained release characteristics of nanoparticles, while free CIP was less effective on the inhibition of bacterial growth. These results indicated that CIP-encapsulated PLGA nanoparticles have superior effectiveness to inhibit the growth of bacteria in vivo.


Assuntos
Antibacterianos/farmacologia , Ciprofloxacina/farmacologia , Portadores de Fármacos , Ácido Láctico/química , Nanopartículas , Ácido Poliglicólico/química , Animais , Antibacterianos/química , Química Farmacêutica , Ciprofloxacina/química , Preparações de Ação Retardada , Composição de Medicamentos , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Cinética , Camundongos , Camundongos Endogâmicos ICR , Testes de Sensibilidade Microbiana , Tamanho da Partícula , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Solubilidade , Tecnologia Farmacêutica/métodos
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