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Kim S, Ozalp EI, Darwish M, Weldon JA. Electrically gated nanoporous membranes for smart molecular flow control. NANOSCALE 2018; 10:20740-20747. [PMID: 30398271 DOI: 10.1039/c8nr05906c] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
We report a novel conductive nanoporous membrane platform for a smart drug delivery system, which allows low-power electrically controlled delivery of therapeutic drug molecules via field-effect gating. The device was fabricated and tested with two oppositely charged drug molecules for glaucoma treatment. Drug molecules with the same polarity as the channel potential are excluded from the nanochannel by electrostatic repulsion, while molecules with opposite charge are enriched due to electrostatic attraction. Accordingly, the diffusive flow of the charged molecules can be controlled by a single DC gate voltage without the need for any other mechanism. An anodic aluminum oxide (AAO) membrane with 80 nm pore diameter was functionalized by sputtering a chromium (Cr)-gold (Au)-chromium (Cr) stack. The exterior chromium layer was left to oxidize creating the insulation layer for the gate electrode. The resulting pore size was 50 nm in diameter. The +2 V gate voltage increased the transport rate of the ethacrynic acid, which is negatively charged at pH 7.4, by 337% and the -2 V gate voltage decreased the transport rate by 48%. The transport rate of the timolol maleate, which is positively charged in pH 7.4, was decreased by 66% with +2 V gate voltage and increased by 116% with -2 V gate voltage. The transport control was quantified by the on-off ratio (OOR), which is the ratio between the maximum and minimum transport rate. The OOR was altered by surface treatment of the membrane. Removal of the surface charge decreased the OOR of ethacrynic acid from 6.94 to 5.61 and increased the OOR of timolol maleate from 1.36 to 1.99. These measurements were verified by our simulation results. In the simulations, the OOR of ethacrynic acid was decreased from 5.22 to 3.25 and the OOR of timolol maleate was increased from 1.90 to 3.25.
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Affiliation(s)
- Sungho Kim
- Department of Electrical & Computer Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA
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Yan L, Liu C, Shen L, Li J, Liu X, Lv M, Su C, Ye Z. Visual Discrimination of 2-Picolinic Acid by a Supramolecular Metallogel. CHEM LETT 2018. [DOI: 10.1246/cl.180065] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Liwei Yan
- College of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu 610500, P. R. China
| | - Cheng Liu
- College of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu 610500, P. R. China
| | - Linghong Shen
- College of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu 610500, P. R. China
| | - Jialing Li
- College of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu 610500, P. R. China
| | - Xuan Liu
- College of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu 610500, P. R. China
| | - Mingqian Lv
- College of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu 610500, P. R. China
| | - Chunjiao Su
- College of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu 610500, P. R. China
| | - Zhongbin Ye
- College of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu 610500, P. R. China
- Oil &Gas Field Applied Chemistry Key Laboratory of Sichuan Province, Southwest Petroleum University, Chengdu 610500, P. R. China
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Arce VB, Gargarello RM, Ortega F, Romañano V, Mizrahi M, Ramallo-López JM, Cobos CJ, Airoldi C, Bernardelli C, Donati ER, Mártire DO. EXAFS and DFT study of the cadmium and lead adsorption on modified silica nanoparticles. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2015; 151:156-163. [PMID: 26135536 DOI: 10.1016/j.saa.2015.06.093] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 06/17/2015] [Accepted: 06/18/2015] [Indexed: 06/04/2023]
Abstract
Silica nanoparticles of 7 nm diameter were modified with (3-aminopropyl) triethoxysilane (APTES) and characterized by CP-MAS (13)C and (29)Si NMR, FTIR, zeta potential measurements, and thermogravimetry. The particles were shown to sorb successfully divalent lead and cadmium ions from aqueous solution. Lead complexation with these silica nanoparticles was clearly confirmed by EXAFS (Extended X-ray Absorption Fine Structure) with synchrotron light measurements. Predicted Pb-N and Pb-C distances obtained from quantum-chemical calculations are in very good agreement with the EXAFS determinations. The calculations also support the higher APTES affinity for Pb(2+) compared to Cd(2+).
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Affiliation(s)
- Valeria B Arce
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), CCT-La Plata-CONICET, Universidad Nacional de La Plata, Diag 113 y 64, 1900 La Plata, Argentina; Centro de Investigaciones Ópticas (CIOp), CONICET La Plata-CIC, CC 3, 1897 Gonnet, La Plata, Argentina
| | - Romina M Gargarello
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), CCT-La Plata-CONICET, Universidad Nacional de La Plata, Diag 113 y 64, 1900 La Plata, Argentina
| | - Florencia Ortega
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), CCT-La Plata-CONICET, Universidad Nacional de La Plata, Diag 113 y 64, 1900 La Plata, Argentina
| | - Virginia Romañano
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), CCT-La Plata-CONICET, Universidad Nacional de La Plata, Diag 113 y 64, 1900 La Plata, Argentina
| | - Martín Mizrahi
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), CCT-La Plata-CONICET, Universidad Nacional de La Plata, Diag 113 y 64, 1900 La Plata, Argentina
| | - José M Ramallo-López
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), CCT-La Plata-CONICET, Universidad Nacional de La Plata, Diag 113 y 64, 1900 La Plata, Argentina
| | - Carlos J Cobos
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), CCT-La Plata-CONICET, Universidad Nacional de La Plata, Diag 113 y 64, 1900 La Plata, Argentina
| | - Claudio Airoldi
- Chemistry Institute, University of Campinas, P.O. Box 6154, 13084-971 Campinas, São Paulo, Brazil
| | - Cecilia Bernardelli
- Centro de Investigación y Desarrollo en Fermentaciones Industriales, CINDEFI (CCT La Plata-CONICET, Universidad Nacional de La Plata), Facultad de Ciencias Exactas, 50 y 115, 1900 La Plata, Argentina
| | - Edgardo R Donati
- Centro de Investigación y Desarrollo en Fermentaciones Industriales, CINDEFI (CCT La Plata-CONICET, Universidad Nacional de La Plata), Facultad de Ciencias Exactas, 50 y 115, 1900 La Plata, Argentina
| | - Daniel O Mártire
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), CCT-La Plata-CONICET, Universidad Nacional de La Plata, Diag 113 y 64, 1900 La Plata, Argentina.
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Melo Jr MA, Pires CTGVMT, Airoldi C. The influence of the leaving iodine atom on phyllosilicate syntheses and useful application in toxic metal removal with favorable energetic effects. RSC Adv 2014. [DOI: 10.1039/c4ra06615d] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Rehman F, Volpe PLO, Airoldi C. Free amino and imino-bridged centres attached to organic chains bonded to structurally ordered silica for dye removal from aqueous solution. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2014; 133:135-143. [PMID: 24374243 DOI: 10.1016/j.jenvman.2013.11.042] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2013] [Revised: 11/13/2013] [Accepted: 11/22/2013] [Indexed: 06/03/2023]
Abstract
Ordered mesoporous SBA-15 type silica was synthesized by sol gel polymerization and reacted with 3-aminopropyltriethoxysilane (AP) or triethylenetetramine (TE), to attach pendant chains or bridging molecules, with basic centres. The materials were characterized by elemental analysis, infrared spectroscopy, and nuclear magnetic resonance in the solid state, X-ray diffractometry, scanning and transmission electron microscopy. The nitrogen sorption/desorption data for SBA-15 and the organofunctionalized SBA-15AP and SBA-15TE silicas resulted in IV type isotherms with hysteresis loops of the H1 type, surface areas of 800; 213 and 457 m(2) g(-1) and average pore diameters of 8.0; 3.2 and 6.8 nm, respectively. The ordered structural features of the mesoporous silica remained preserved after post-functionalization with pendant and bridged organic chains. Sorption data for organofunctionalized silicas gave highly selective sorption capacities for anionic water soluble Reactive Blue dye, with 0.064 and 0.072 mmol g(-1). Negligible sorption was observed with the unmodified mesoporous silica. The results suggest that organofunctionalized silica can be a simple, efficient, inexpensive and suitable method for the effective and selective removal of anionic organic dye pollutants from aqueous solutions.
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Affiliation(s)
- Fozia Rehman
- Institute of Chemistry, University of Campinas, UNICAMP, P.O. Box 6154, 13084-971 Campinas, SP, Brazil
| | - Pedro L O Volpe
- Institute of Chemistry, University of Campinas, UNICAMP, P.O. Box 6154, 13084-971 Campinas, SP, Brazil
| | - Claudio Airoldi
- Institute of Chemistry, University of Campinas, UNICAMP, P.O. Box 6154, 13084-971 Campinas, SP, Brazil.
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Zhang M, Liang X, Jiang S, Qiu H. Preparation and applications of surface-confined ionic-liquid stationary phases for liquid chromatography. Trends Analyt Chem 2014. [DOI: 10.1016/j.trac.2013.09.011] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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Melo MA, Airoldi C. Energetic features of copper and lead sorption by innovative aminoalcohol-functionalized cobalt phyllosilicates. Dalton Trans 2010; 39:10217-27. [PMID: 20922219 DOI: 10.1039/c0dt00413h] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Inorganic-organic cobalt phyllosilicate hybrids were synthesized by the sol-gel procedure under mild non-hydrothermal conditions with a silicon precursor, formed through individual reactions between the silane 3-glycidoxypropyltriethoxysilane and the aminoalcohols ethanol- or diethanolamine. These procedures generated talc-like phyllosilicates containing pendant organic chains with nitrogen and oxygen basic centres located in the interlamellar region. For organofunctionalized phyllosilicates the lamellar structure obtained through the sol-gel method was confirmed by X-ray powder diffraction, while elemental analysis indicated that the densities of the organic groups attached to the new matrices were 3.31 ± 0.05 and 3.08 ± 0.07 mmol g(-1) for hybrids functionalized with ethanol- and diethanolamines, respectively. Infrared spectroscopy and nuclear magnetic resonance in the solid state for (13)C and (29)Si showed that the organic groups are indeed covalently bonded to the inorganic structures and the process of functionalization did not affect the original structures of the silylating agents employed. The thermally stable hybrids presented well-formed particles with a homogeneous distribution of cobalt and nitrogen atoms. Their abilities for copper removal from aqueous solutions gave maximum capacities of sorption of 2.01 ± 0.11 and 2.55 ± 0.15 mmol g(-1) for phyllosilicates containing ethanol- and diethanolamine groups, respectively. For lead sorption the values of 2.59 ± 0.11 and 2.43 ± 0.12 mmol g(-1) were found for this same sequence. These sorption data were adjusted to the non-linear regression of the Langmuir equation. Energetic features related to the interactions between the cations and the pendant basic centres were determined through calorimetric titrations. The acid-basic interactions reflect the spontaneity of the reactions, which are also enthalpically and entropically favourable for these chelating processes at the solid-liquid interface.
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Affiliation(s)
- Maurício Alves Melo
- Institute of Chemistry, University of Campinas, P.O. Box 6154, 13084-971 Campinas, São Paulo, Brazil
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Royer B, Cardoso NF, Lima EC, Macedo TR, Airoldi C. A useful organofunctionalized layered silicate for textile dye removal. JOURNAL OF HAZARDOUS MATERIALS 2010; 181:366-374. [PMID: 20554108 DOI: 10.1016/j.jhazmat.2010.05.019] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2010] [Revised: 04/13/2010] [Accepted: 05/05/2010] [Indexed: 05/29/2023]
Abstract
The octosilicate Na-RUB-18 has the ability to exchange its original sodium with cetyltrimethylammonium cations. This procedure leads to interlayer space expansion, with the aim of obtaining inorganic-organic nanostructured hybrids by chemical modification reactions. The silylating agent 3-trimethoxysilylpropylurea was attached to the inorganic layer using heterogeneous methodology. The new organofunctionalized material was characterized by elemental analysis, X-ray diffraction, (13)C and (29)Si nuclear magnetic resonances in the solid state, infrared spectroscopy, thermogravimetry and scanning electron microscopy. The amount of silylating agent immobilized on surface was 2.03 mmol g(-1), with a basal distance of 2.43 nm. Nuclear magnetic resonance of (13)C and (29)Si nuclei evidenced covalent bond formation between organosilyl and silanol groups at the surface. The new synthesized nanostructured layered material was able to remove the textile dye Reactive Black 5 from aqueous solution, followed through a batchwise process. The effects of stirring time, adsorbent dosage and pH on the adsorption capacity demonstrated that 150 min is enough to reach equilibrium at 298+/-1 K at pH 3.0. Based on error function values the data were best fitted to fractional-order kinetic models and compared to pseudo-first-order, pseudo-second-order and chemisorption kinetic models. The equilibrium data were better fitted to the Sips isotherm models.
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Affiliation(s)
- Betina Royer
- Institute of Chemistry, Federal University of Rio Grande do Sul, UFRGS, Porto Alegre, Rio Grande do Sul, Brazil
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Macedo TR, Airoldi C. New inorganic–organic lamellar derivatives synthesized from H-RUB-18 and thermodynamics of cation sorption. NEW J CHEM 2009. [DOI: 10.1039/b9nj00280d] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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