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1.
J Control Release ; 366: 142-159, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38145660

RESUMEN

Responsive heat resistance (by heat shock protein upregulation) and spontaneous reactive oxygen species (ROS) detoxification have been regarded as the major obstacles for photothermal/photodynamic therapy of cancer. To overcome the thermal resistance and improve ROS susceptibility in breast cancer therapy, Au ion-crosslinked hydrogels including indocyanine green (ICG) and polyphenol are devised. Au ion has been introduced for gel crosslinking (by catechol-Au3+ coordination), cellular glutathione depletion, and O2 production from cellular H2O2. ICG can generate singlet oxygen from O2 (for photodynamic therapy) and induce hyperthermia (for photothermal therapy) under the near-infrared laser exposure. (-)-Epigallocatechin gallate downregulates heat shock protein to overcome heat resistance during hyperthermia and exerts multiple anticancer functions in spite of its ironical antioxidant features. Those molecules are concinnously engaged in the hydrogel structure to offer fast gel transformation, syringe injection, self-restoration, and rheological tuning for augmented photo/chemotherapy of cancer. Intratumoral injection of multifunctional hydrogel efficiently suppressed the growth of primary breast cancer and completely eliminated the residual tumor mass. Proposed hydrogel system can be applied to tumor size reduction prior to surgery of breast cancer and the complete remission after its surgery.


Asunto(s)
Neoplasias de la Mama , Hipertermia Inducida , Fotoquimioterapia , Humanos , Femenino , Especies Reactivas de Oxígeno/metabolismo , Hidrogeles/uso terapéutico , Peróxido de Hidrógeno , Verde de Indocianina/uso terapéutico , Verde de Indocianina/química , Neoplasias de la Mama/tratamiento farmacológico , Proteínas de Choque Térmico
2.
Gels ; 9(10)2023 Oct 19.
Artículo en Inglés | MEDLINE | ID: mdl-37888400

RESUMEN

Toxic metal ions present in industrial waste, such as Pb(II), introduce deleterious effects on the environment. Though the adsorptive removal of Pb(II) is widely reported, there is a dearth of research on the suitable utilization and disposal of the Pb(II)-adsorbed adsorbent. In this work, an MXene-grafted terpolymer (MXTP) hydrogel has been designed for the adsorption of Pb(II) under ambient conditions of pH and temperature. The hydrogel MXTP was synthesized by facile one-pot polymerization in aqueous solvent, and the detailed structural characterization of terpolymer (TP), MXTP, and Pb(II)-loaded MXTP, i.e., Pb(II)-MXTP, was carried out by a combination of proton nuclear magnetic resonance (1H NMR), Fourier-transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), X-ray diffractometric (XRD), thermogravimetric/differential thermogravimetric (TG/ DTG), and field emission scanning electron microscopic (FESEM) analyses. The specific capacitance and conductivities of Pb(II)-MXTP were studied with cyclic voltammetry (CV) and electrical impedance spectroscopy (EIS), which unambiguously indicate successful post-adsorption application. The specific capacitance of MXTP decreased after Pb(II) adsorption, whereas the conductivity increased significantly after Pb(II) adsorption, showing that MXTP can be successfully deployed as a solid electrolyte/anode after Pb(II) adsorption. This study covers the synthesis of a novel MXene-grafted terpolymer hydrogel for adsorptive exclusion of Pb(II) and assessment of the as-adsorbed Pb(II)-loaded hydrogel as a solid electrolyte/anode material and is the first demonstration of such post-adsorptive application.

3.
J Control Release ; 362: 1-18, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37595669

RESUMEN

Alum-crosslinked hyaluronic acid-dopamine (HD) hydrogel containing indocyanine green (ICG) with anti-programmed cell death-1 (PD-1) antibody (Ab) administration was developed for immunophoto therapy of cancer. Alum modulates the rheological characteristics of hydrogel for enabling syringe injection, shear-thinning feature, and slower biodegradation. In addition, alum in HD-based hydrogel provided CD8+ T cell-mediated immune responses for cancer therapy. ICG in the hydrogel under near-infrared (NIR) light exposure may induce hyperthermia and generate singlet oxygen for selective cancer cell killing. HD/alum/ICG hydrogel injection with NIR laser irradiation elevated PD-1 level in CD8+ T cells. Administration of PD-1 Ab aiming at highly expressed PD-1 in T cells may amplify the anticancer efficacies of HD/alum/ICG hydrogel along with NIR laser. HD/alum/ICG hydrogel with NIR light may have both CD8+ T cell-linked immune responses and ICG-related photodynamic/photothermal effects. Additional injection of immune checkpoint inhibitor can ultimately suppress primary and distant tumor growth by combination with those therapeutic actions.

4.
Pharmaceutics ; 15(7)2023 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-37514021

RESUMEN

The development of metal salts-based nanocomposites is highly desired for the Fenton or Fenton-like reaction-based chemodynamic therapy of cancer. Manganese sulfate (MnSO4)-dispersed nanoparticles (NPs) were fabricated with a hot-melt extrusion (HME) system for the chemodynamic therapy of colorectal cancer in this study. MnSO4 was homogeneously distributed in polyethylene glycol (PEG) 6000 (as a hydrophilic polymer) with the aid of surfactants (Span 80 and Tween 80) by HME processing. Nano-size distribution was achieved after dispersing the pulverized extrudate of MnSO4-based composite in the aqueous media. The distribution of MnSO4 in HME extrudate and the interactions between MnSO4 and pharmaceutical additives were elucidated by Fourier-transform infrared, X-ray diffractometry, X-ray photoelectron spectroscopy, and scanning electron microscopy analyses. Hydroxyl radical generation efficiency by the Fenton-like chemistry capability of Mn2+ ion was also confirmed by catalytic assays. By using the intrinsic H2O2 in cancer cells, MnSO4 NPs provided an elevated cellular reactive oxygen species level, apoptosis induction capability, and antiproliferation efficiency. The designed HME-processed MnSO4 formulation can be efficiently used for the chemodynamic therapy of colorectal cancer.

5.
J Environ Manage ; 294: 112932, 2021 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-34130137

RESUMEN

In this work, an optimum sodium alginate (NaAlg)-grafted-[sodium 2-methylenesuccinate-co-sodium 2-((2-(isobutyryloxy)ethoxy)methyl)succinate-co-ethylene glycol methacrylate, i.e., SMS-co-SIBEMS-co-EGMA, i.e., P1], i.e., P2, was selected among twelve hydrogels synthesized by employing variable amounts of synthesis parameters through a facile polymerization of SMS and EGMA monomers. In P1 and P2, SIBEMS third comonomer was strategically anchored in situ. The formation of terpolymer, i.e., P1, rather than generally expected copolymer, i.e., SMS-co-EGMA/ CoP1, was explored via closeness of experimental and simulated excitation energies of P1 and CoP1, measured by using density functional theory (DFT). The grafting of NaAlg into synthetic P1 elevated swelling, crosslink density (CD), network stability, reusability, and adsorption capacity (AC) of semisynthetic hydrogel, i.e., P2. The reusable P2 presenting optimum result among swelling, CD, and mean molar mass was chosen selectively for removals of As(III) and V(V). The structures of P1, P2, and adsorbed P2, i.e., As(III)-P2 and V(V)-P2; NaAlg-grafting; in situ anchored SIBEMS comonomer; reusability; thermostability; and surface properties were explored through XPS-NMR-FTIR-UV-vis, DFT, TG, DLS, XRD, SEM, pHPZC, and network and thermodynamic energies. The ACs of 0.025 g P2 for As(III) and V(V) were 112.24 and 88.89 mg g-1, respectively, at 308 K and within 5-100 mg L-1. The ACs reduced to 67.26, 75.49, 71.42, and 98.25 mg g-1 for As(III) and 40.25, 50.49, 45.37, and 67.88 mg g-1 for V(V) in the presence of Mn(II), Cu(II), Ni(II), and Zn(II), respectively.


Asunto(s)
Alginatos , Hidrogeles , Adsorción , Polimerizacion , Polímeros
6.
Int J Biol Macromol ; 184: 909-925, 2021 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-34144070

RESUMEN

Microwave assisted homogeneous heating, selectivity in radical formation, and the faster polymerization facilitate the synthesis, structures, properties, and the higher branching associated stability of multifunctional multipolymers. Thus, the optimum gum tragacanth (GMTR)-grafted pentapolymer hydrogel/ HG2 was synthesized from three monomers, i.e., cis-butenedioic acid (cBDA), N-hydroxymethylacryalamide (NHMAm), and 2-(methacryloyloxy)ethanol (MAOE), and in situ generated 2-(3-((hydroxymethyl)amino)-3-oxopropoxy)ethyl-2-methylbutanoate (CM1) and 2-hydroxyethyl 3-(N-(hydroxymethyl)-2-methylbutanamido)-2-methylpropanoate (CM2) comonomers through microwave assisted facile polymerization in aqueous medium. Here, twenty-one GMTR-grafted-[cBDA-co-CM1-co-NHMAm-co-CM2-co-MAOE/ HG1] hydrogels were prepared by using variable amounts of synthesis parameters, of which the optimum HG2 was chosen for the scale-up repetitive As(III)-exclusion. RSM was used to measure the optimum power-temperature-time of microwave irradiation. The structures of HG1, HG2, and As(III)-adsorbed HG2/ As(III)-HG2, in situ anchored comonomers, GMTR-grafting, reusability, thermostability, and surface phenomena were comprehended by XPS, NMR, UV-vis, FTIR, TG, XRD, DLS, and SEM analyses; pHPZC; network parameters; and thermodynamic variables. The geometries, electronic structures, and variable coordinations of As(III) with HG2 were investigated through DFT studies of HG2 and As(OH)3-HG2. The highest exclusion efficiency of 25 mg HG2 within 5-100 mg L-1 As(III) and at 298 K was 192.91 mg g-1, which was significantly higher than that of HG1.


Asunto(s)
Sustancias Macromoleculares/síntesis química , Tragacanto/química , Adsorción , Teoría Funcional de la Densidad , Hidrogeles , Concentración de Iones de Hidrógeno , Sustancias Macromoleculares/química , Microondas , Estructura Molecular , Polimerizacion , Temperatura
7.
J Hazard Mater ; 409: 124873, 2021 05 05.
Artículo en Inglés | MEDLINE | ID: mdl-33548741

RESUMEN

Herein, hazardous solid particulate waste collagenic fibers (SWCFs) of leather industries were incorporated into apple pomace pectin (APPN)-grafted-pentapolymer, i.e., APPN-g-[sodium 2-methylidenebutanedioate(SMBD)-co-N-((3-(isopropylamino)-3-oxopropoxy) methyl) butyramide (CM1)-co-N-(hydroxymethyl)prop-2-enamide (NHMPE)-co-N-(hydroxymethyl)-4-(N-isopropylbutyramido)butanamide (CM2)-co-N-(propan-2-yl)prop-2-enamide NPYPE)/ PENP1], i.e., APPN-g-PENP1/ PENP2, prepared via one-pot facile polymerization of APPN and synthetic monomers, i.e., SMBD, NHMPE, and NPYPE, in aqueous medium, to fabricate an optimum multifunctional hybrid biocomposite adsorbent/ HCOM3. In PENP1, PENP2, and HCOM3, fourth/ CM1 and fifth/ CM2 multifunctional comonomers were anchored in situ. The structures of PENP1, PENP2, HCOM3, CM1, CM2, and metal-ion adsorbed HCOM3; APPN-grafting; SWCF incorporation; and surface properties were analyzed through NMR, XPS, FTIR, XRD, and SEM. The elevated adsorption efficiencies (AEs), reusability, thermostability, swelling, network durability, and crosslink density of HCOM3 were attributed to variable functionalities of SWCF/ APPN, explored by DLS and TGA, swelling, network, and thermodynamic parameters. Compared to SWCF, APPN, PENP1, and PENP2, the elevated AEs and reusability compelled HCOM3 as more suitable for scalable waste management. The maximum AEs, i.e., 171.79, 180.47, and 177.27 mg g-1, for Ti(IV), As(V), and V(V) at pHop = 7.0, 3.0, and 5.0, respectively, within 5-100 mg L-1 and at 298 K for 25 mg HCOM3 deteriorated during ternary adsorption by the antagonistic effects.

8.
Carbohydr Polym ; 245: 116370, 2020 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-32718590

RESUMEN

New property-performance optimization approach of purely-aliphatic scalable-and-reusable multifunctional terpolymer hydrogels envisaging the excellent performance potential has been reported. Accordingly, the optimum potassium alginate (KA)-g-[2-hydroxyethylmethacrylate (HEMA)-co-3-(2-(isobutyryloxy)ethoxy)-2-methylpropanoic acid (IBEMPA)-co-methacrylic acid (MAA)/ 1], i.e., 2, among twelve KA-grafted terpolymer hydrogels has been designed and synthesized via OH functionalized OC/ CC coupled in situ protrusion of third monomer, i.e., IBEMPA, and grafting of KA into 1 in polymerization of two monomers employing variable monomer ratio; pH; amounts of KA, crosslinker, and initiators; and temperatures. The structures of 1/ 2, in situ IBEMPA, grafted-KA, thermal stabilities, surface properties, superadsorption mechanism, and reusability have been explored via 1H/ 13C NMR, FTIR, XPS, TGA, XRD, SEM, DLS, network parameters, pHPZC, %graft-ratio, %gel-content, and thermodynamic-parameters. The maximum adsorption capacities of Ce(IV), Mo(VI), and W(VI) are 1575.57, 1581.32, and 1990.11 mg g-1, respectively, within 500-1000 ppm at 308 K for 0.02 g adsorbent.


Asunto(s)
Alginatos/química , Cerio/química , Molibdeno/química , Polímeros/química , Oligoelementos/química , Tungsteno/química , Adsorción , Hidrogeles/química , Enlace de Hidrógeno , Concentración de Iones de Hidrógeno , Interacciones Hidrofóbicas e Hidrofílicas , Iones , Polimerizacion , Temperatura , Contaminantes del Agua/química
9.
ACS Appl Bio Mater ; 3(9): 6155-6166, 2020 Sep 21.
Artículo en Inglés | MEDLINE | ID: mdl-35021748

RESUMEN

Intrinsically fluorescent biocompatible multifunctional multipurpose terpolymers, i.e., methyl methacrylate-co-methyl 3-(N-isopropylacrylamido)-2-methylpropanoate-co-N-isopropylacrylamide (MMA-co-MNIPAMP-co-NIPAm, 1) and methyl methacrylate-co-methyl 3-(N-hydroxymethylacrylamido)-2-methylpropanoate-co-N-hydroxymethylacrylamide (MMA-co-MNHMAMP-co-NHMAm, 2), were synthesized via in situ-attached acrylamido-ester monomers during polymerization of hydrophobic monomers in water medium. These nonconjugated fluorescent terpolymers presenting aggregation-enhanced emissions (AEEs) were suitable for Bi(III) sensors, Bi(III) removal, cell imaging, and security inks. The fluorescence properties, mechanisms of quenching, interactions of Bi(III) with 1 and 2, and Bi(III) adsorption were explored using theoretical analyses of 1, 2, Bi(III)-1, and Bi(III)-2. Considering the overall properties, 1 was more suitable for diverse prospective applications.

10.
Environ Res ; 179(Pt B): 108839, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31679719

RESUMEN

For circumventing the cumbersome and expensive multifunctional and multipolymer adsorbents for high-performance removals of hazardous water-contaminant(s), chitosan-g-[2-acrylamido-2-methyl-1-propanoic acid (AMPS)-co-2-(3-acrylamidopropanamido)-2-methylpropane-1-sulfonic acid (APAMPS)-co-2-(N-(3-amino-3-oxopropyl)acrylamido)-2-methylpropane-1-sulfonic acid (NAOPAMPS)-co-acrylamide (AM)] (i.e., chitosan-g-tetrapolymer), a multifunctional scalable and reusable hydrogel, was synthesized by grafting of chitosan and in situ attachments of N-H functionalized NAOPAMPS and APAMPS hydrophilic acrylamido-monomers during free-radical solution-polymerization of the two ex situ added AMPS and AM monomers in water. The response surface methodology was employed to synthesize one hydrogel envisaging the optimum balance between swelling and stability for the superadsorption of Cu(II), Cd(II), Pb(II), Cr2O72-, and HPO42-. The in situ attachments of NAOPAMPS and APAMPS, grafting of chitosan into tetrapolymer, structures and properties, pH-responsive abilities, superadsorption mechanism, and reusability were understood via in depth microstructural analyses of adsorbed and/or unadsorbed chitosan-g-tetrapolymer(s) through 1H/13C NMR, FTIR, XPS, TGA, XRD, DLS, and pHPZC. The maximum adsorption capacities of Cd(II), Cu(II), Pb(II), Cr2O72-, and HPO42- were 1374.41, 1521.08, 1554.08, 47.76, and 32.76 mg g-1, respectively.


Asunto(s)
Quitosano/química , Metales/química , Polímeros/química , Contaminantes Químicos del Agua/química , Adsorción , Cadmio , Cromatos/análisis , Cromatos/química , Concentración de Iones de Hidrógeno , Plomo , Metales/análisis , Fosfatos/análisis , Fosfatos/química , Contaminantes Químicos del Agua/análisis , Purificación del Agua
11.
Membranes (Basel) ; 9(5)2019 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-31052381

RESUMEN

For the fulfilment of increasing global demand and associated challenges related to the supply of clean-and-safe water, PV has been considered as one of the most attractive and promising areas in desalinating salty-water of varied salinities. In pervaporative desalination, the sustainability, endurance, and structural features of membrane, along with operating parameters, play the dominant roles and impart paramount impact in governing the overall PV efficiency. Indeed, polymeric- and organic-membranes suffer from several drawbacks, including inferior structural stability and durability, whereas the fabrication of purely inorganic membranes is complicated and costly. Therefore, recent development on the high-performance and cost-friendly PV membrane is mostly concentrated on synthesizing composite- and NCP-membranes possessing the advantages of both organic- and inorganic-membranes. This review reflects the insights into the physicochemical properties and fabrication approaches of different classes of PV membranes, especially composite- and NCP-membranes. The mass transport mechanisms interrelated to the specialized structural features have been discussed. Additionally, the performance potential and application prospects of these membranes in a wide spectrum of desalination and wastewater treatment have been elaborated. Finally, the challenges and future perspectives have been identified in developing and scaling up different high-performance membranes suitable for broader commercial applications.

12.
J Hazard Mater ; 369: 746-762, 2019 05 05.
Artículo en Inglés | MEDLINE | ID: mdl-30836295

RESUMEN

Herein, guar gum (GG)-g-(acrylic acid (AA)-co-3-acrylamido propanoic acid (AMPA)-co-acrylamide (AM))-g-cow buffing dust (CBD)/(GGTPCBD), a smart carbohydrate and protein-based doubly-grafted interpenetrating terpolymer hydrogel showing excellent physicochemical properties and recyclability was synthesized by in situ strategic allocation of AMPA during solution polymerization of AA and AM through systematic optimization of the amounts of components and reaction temperature for superadsorption of Hg(II), Pb(II), methyl violet (MV), methylene blue (MB), p-nitrophenol (PNP), and vitamin-C (vit.C). The in situ strategic protrusion of AMPA, grafting of both GG and CBD into AA-co-AMPA-co-AM, and ligand-selective superadsorption was inferred by advanced microstructural analyses of unadsorbed- and/or adsorbed-GGTPCBD using FTIR, 1H/13C NMR, O1s-/N1s-/C1s-/Pb4f7/2,5/2-/Hg4f7/2,5/2-XPS, UV-vis, TGA, DSC, XRD, DLS, SEM, EDX, % gel content, % -COOH, and pHPZC. The prevalence of covalent, ionic, and variegated interactions was rationalized by FTIR, fitting of kinetics data to the pseudosecond order model, and activation energies of adsorption. The BET and Langmuir isotherms fitted the best to MB and Hg(II)/Pb(II)/MV, respectively. Thermodynamically spontaneous chemisorption processes showed the maximum adsorption capacities (ACs) of 976.64, 859.23, 116.80, and 58.52 mg g-1 for Pb(II), Hg(II), MV, and MB, respectively, at 303 K, adsorbent dose = 0.01 g, and initial concentration of metal ions/dyes = 800/30 ppm.

13.
Carbohydr Polym ; 213: 428-440, 2019 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-30879688

RESUMEN

Response surface methodology (i.e., RSM)-optimized starch-g-[2-acrylamido-2-methylpropane sulfonic acid (AMPS)-co-[2-(N-(3-(hydroxymethyl)amino)-3-oxopropyl)acrylamido)-2-methylpropane sulfonic acid] (NHMAOAMPS)-co-[2-(3-(N-(hydroxymethyl)acrylamido)propanamido)-2-methylpropane sulfonic acid (NHMAPMPS)]-co-N-(hydroxymethyl)acrylamide (NHMA)] (i.e., starch-g-tetrapolymer) was synthesized via grafting of starch and in situ strategic protrusion of NHMAOAMPS and NHMAPMPS, using optimum ingredients and temperature. This interpenetrating tetrapolymer-hydrogel bearing extraordinary physicochemical properties and recyclability was applied for unary and/or binary removal(s) of Bi(III)-Hg(II) and brilliant green-crystal violet. The N-H-activated in situ allocation of monomers, grafting of starch, thermal stabilities, surface properties, swellability, sustainability, adsorption capacities, and superadsorption were apprehended via microstructural analyses of unadsorbed and/or adsorbed starch-g-tetrapolymer(s) through FTIR-1H-/13C-NMR-UV-vis, TGA-DSC, XRD, SEM-EDX, DLS, and %gel-content-pHPZC-%graft-ratio. The chemisorption data for metal ions best fitted with Langmuir and combined Langmuir-Freundlich isotherm models for unary and binary adsorption, respectively. The unary/binary adsorption capacities were 1005.41/959.25 and 1087.79/758.56 mg g-1 for Bi(III) and Hg(II), respectively, at 293 K, 0.02 g, and within 500-1000 ppm.

14.
J Hazard Mater ; 369: 199-213, 2019 05 05.
Artículo en Inglés | MEDLINE | ID: mdl-30776603

RESUMEN

Goat buffing dust (GBD), an abundantly available collagenic-waste and crosslinked styrene butadiene rubber (SBR)-based scalable biocomposite showing excellent physicochemical properties and reusability was synthesized via systematic optimization of torque and time for exclusion(s) of dyes, such as safranine (SF) and brilliant cresyl blue (BCB), and Hg(II). The GBD-aided non-sulfur curing of SBR was attempted via chromane mechanism-based reaction between resin components of GBD and pendant ̶ C=C ̶ of SBR. The decrease in the relative extent of unsaturation in cured-SBRGBD, alteration of crystallinity, surface properties, elevated thermal stabilities, and ligand-selective superadsorption were inferred through extensive microstructural analyses of unadsorbed and/or adsorbed SBRGBD using 13C NMR, O1s-/N1s-/C1s-/Hg4f7/2,5/2-XPS, FTIR, UV-vis, TGA, XRD, FESEM, and EDX. Interactive effects between pHi, temperature, and concentration on adsorption capacities (ACs) were optimized through response surface methodology (RSM). The ionic interaction between SBRGBD and SF, BCB, and Hg(II) was understood through FTIR analyses, fitting of kinetics data to pseudosecond order model, and activation energies. BET and Langmuir isotherms were fitted the best to BCB and SF/Hg(II), respectively. Thermodynamically spontaneous chemisorption showed the maximum ACs of 165.63, 251.18, and 225.56 mg g-1 for SF, BCB, and Hg(II), respectively, at 100 ppm, 303 K, and adsorbent dose = 0.015 g.


Asunto(s)
Colágeno/química , Mercurio/química , Oxazinas/química , Fenazinas/química , Eliminación de Residuos/métodos , Adsorción , Colorantes/química , Análisis Costo-Beneficio , Cinética , Espectroscopía de Resonancia Magnética , Espectroscopía de Fotoelectrones , Goma , Espectrofotometría Ultravioleta , Espectroscopía Infrarroja por Transformada de Fourier , Termodinámica , Termogravimetría , Contaminantes Químicos del Agua/química , Difracción de Rayos X
15.
Carbohydr Polym ; 206: 778-791, 2019 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-30553384

RESUMEN

Pectin (PC)-g-[methacrylic acid (MAA)-co-3-(N-isopropylacrylamido)-2-methylpropanoic acid (NIPAMPA)-co-N-isopropylacrylamide (NIPA)] (i.e., PC-g-TP), a novel interpenetrating terpolymer network hydrogel of excellent physicochemical properties and reusability, was synthesized via grafting of PC and in situ strategic protrusion of third monomer, i.e., NIPAMPA, during polymerization of MAA and NIPA, using response surface methodology optimized amounts of ingredients and temperature, for superadsorption of hazardous metal ions, such as Cd(II), Hg(II), and Pb(II). The in situ allocation of NIPAMPA via NH activation, grafting of PC into MAA-co-NIPAMPA-co-NIPA matrix, physicochemical properties, and superadsorption mechanism were rationalized via extensive microstructural analyses of unadsorbed and/or adsorbed PC-g-TP through 1H-/13C-NMR, XPS, FTIR,TGA, XRD, FESEM, DLS, %gel content, pHPZC, and %graft ratio. The spontaneous chemisorption data exhibited excellent fitting with Langmuir model. The adsorption capacities (ACs) were 1315.32, 1172.97, and 1269.09 mg g-1 for Cd(II), Hg(II), and Pb(II), respectively, at 293 K, 0.02 g of PC-g-TP, and within 500-1000 ppm.

16.
ACS Omega ; 3(1): 472-494, 2018 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-31457906

RESUMEN

Grafting of guar gum (GG) and in situ strategic attachment of acrylamidosodiumpropanoate (ASP) via solution polymerization of acrylamide (AM) and sodium acrylate (SA) resulted in the synthesis of a sustainable GG-g-(AM-co-SA-co-ASP)/GGAMSAASP interpenetrating polymer network (IPN)-based smart superadsorbent with excellent physicochemical properties and reusability, through systematic optimization by response surface methodology (RSM) for removal of methyl violet (MV) and/or Hg(II). The relative effects of SA/AM ratios, in situ allocation of ASP, grafting of GG into the AMSAASP terpolymer, ligand-selective superadsorption mechanism, and relative microstructural changes in individually/synergistically-adsorbed MV-/Hg(II)-/Hg(II)-MV-GGAMSAASPs were determined by extensive analyses using Fourier transform infrared (FTIR), proton nuclear magnetic resonance, ultraviolet-visible (UV-vis), and O 1s-/N 1s-/C 1s-/Hg 4f7/2,5/2-X-ray photoelectron spectroscopies, thermogravimetric analysis, differential scanning calorimetry, X-ray diffraction, field emission scanning electron microscopy, and energy-dispersive spectroscopy and were supported by % gel content, pHPZC, and % graft ratio. The ionic/covalent-bonding, monodentate, bidentate bridging, and bidentate chelating coordination between GGAMSAASPs and Hg(II), and MV+-Hg(II) bonding were rationalized by FTIR, UV-vis, fitment of kinetics data to the pseudo-second-order model, and thermodynamic parameters. The maximum adsorption capacities of 49.12 and 53.28 mg g-1 were determined for Hg(II) and MV, respectively, under optimized conditions.

17.
ACS Omega ; 3(4): 4163-4180, 2018 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-31458651

RESUMEN

Pectin-g-(sodium acrylate-co-3-(N-isopropylacrylamido) sodium propanoate-co-N-isopropylacrylamide) interpenetrating polymer networks (PANIPNs) were synthesized through systematic multistage optimization of equilibrium swelling ratio by response surface methodology for individual and/or synergistic removal(s) of cationic safranine (SF), anionic methyl orange, and M(II/III), such as Hg(II), Cd(II), and Cr(III). The relative effects of copolymer compositions on ligand-selective adsorption, strong/weak H-bonds, thermal stabilities, crystallinity, surface properties, swelling abilities, cross-link densities, network parameters, hydrophilic-hydrophobic characteristics, and adsorption capacities (ACs) were measured through extensive microstructural analyses of adsorbed and/or unadsorbed PANIPN41 and PANIPN21 bearing sodium acrylate and N-isopropylacrylamide (SA/NIPAm) in 4:1 and 2:1 ratios, respectively, using Fourier transform infrared, 1H and 13C NMR, X-ray photoelectron spectroscopy, thermogravimetric analysis, differential scanning calorimetry, X-ray diffraction, scanning electron microscopy, and energy dispersive X-ray spectroscopy, along with measuring lower critical solution temperature, % gel content (% GC), % -COOH, and pHPZC. Extensive UV-vis measurements were carried out at varying copolymer compositions, initial pH (pHi), and dyes, interpreted considering monomer-dimer and azonium-ammonium equilibrium of dye, dye-dye complexation, ligand-selective PANIPNs-dye adduct formation, π-π stacking interactions, and orientation effect of dyes. Thermodynamically feasible chemisorption processes showed the maximum ACs of 127.61, 96.78, 103.36, and 99.41 mg g-1 for SF, Hg(II), Cd(II), and Cr(III), respectively, under optimum conditions.

18.
ACS Omega ; 3(9): 10692-10708, 2018 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-31459187

RESUMEN

Herein, gum ghatti (GGTI)-g-[sodium acrylate (SA)-co-3-(N-(4-(4-methyl pentanoate))acrylamido)propanoate (NMPAP)-co-4-(acrylamido)-4-methyl pentanoate (AMP)-co-N-isopropylacrylamide (NIPA)] (i.e., GGTI-g-TetraP), a novel interpenetrating tetrapolymer network-based sustainable hydrogel, possessing extraordinary physicochemical properties and excellent recyclability, has been synthesized via grafting of GGTI and in situ strategic protrusion of NMPAP and AMP during the solution polymerization of SA and NIPA, through systematic multistage optimization of ingredients and temperature, for ligand-selective superadsorption of hazardous metal ions (M(II)), such as Sr(II), Hg(II), and Cu(II). The in situ allocation of NMPAP and AMP via N-H and C-H activations, grafting of GGTI into the SA-co-NMPAP-co-AMP-co-NIPA (TetraP) matrix, the effect of comonomer compositions on ligand-selective adsorption, crystallinity, thermal stabilities, surface properties, swellability, adsorption capacities (ACs), mechanical properties, and the superadsorption mechanism have been apprehended via extensive microstructural analyses of unloaded and/or loaded GGTI-g-TetraP1 and GGTI-g-TetraP2 bearing SA/NIPA in 8:1 and 2:1 ratios, respectively, using Fourier transform infrared (FTIR), 1H/13C/DEPT-135 NMR, X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis, differential scanning calorimetry, X-ray diffraction, field emission scanning electron microscopy, rheological analysis, and energy-dispersive X-ray spectrometry, along with measuring % gel content, pH at point of zero charge (pHPZC), and % graft ratio. The thermodynamically spontaneous chemisorption has been inferred from FTIR, XPS, fitting of kinetics data to pseudo-second-order model, and activation energies. The chemisorption data have exhibited excellent fitting to the Langmuir isotherm model. For Sr(II), Hg(II), and Cu(II), ACs were 1940.24/1748.36, 1759.50/1848.03, and 1903.64/1781.63 mg g-1, respectively, at 293 K, 0.02 g of GGTI-g-TetraP1/2, and initial concentration of M(II) = 500-1000 ppm.

19.
Int J Biol Macromol ; 102: 438-456, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28416399

RESUMEN

Bovine collagen was functionalized by extensive process modifications for fabricating tanned bovine collagen fibers (TBCFs), as a new semisynthetic macro-, meso- and micro- porous adsorbent, of unprecedented physicochemical properties and excellent industrial waste removal efficiency. Mere or interactive effects were rationally understood, via analyzing monomer-dimer equilibrium, H-/J-aggregate formation, H-bonding, metachromasia, dye-dye complex formation etc., through extensive UV-vis analyses, during removal of acidic, like Acid Brown 369 (AB369), Acid Red 131 (AR131) and Acid Blue 113 (AB113) and basic, like Methylene Blue (MB) dyes. A new strategy was introduced to determine the allocations of these dyes, within macro-, meso- and micro-pores of TBCF, confirmed by FTIR, TGA, DTG, DSC, XRD, SEM, EDX analyses, of both loaded and unloaded TBCFs, and by measuring isotherm, kinetics, diffusion and thermodynamics parameters of adsorption. Freundlich, Langmuir and Sips models were best fitted to AR131, AB113 and AB369, respectively. Interactive effects of concentration, temperature and time, on adsorption capacities (ACs), were optimized via response surface methodology (RSM). ACs of AR131, AB113 and AB369 were 38.29, 78.14 and 73.25mgg-1, respectively, at optimum conditions (i.e. adsorbent dose=0.25g, pHi=4, concentration=200ppm and temperature=299K).


Asunto(s)
Colágeno/química , Colorantes/química , Contaminantes Químicos del Agua/química , Adsorción , Animales , Bovinos , Colorantes/aislamiento & purificación , Cinética , Termodinámica , Agua/química , Contaminantes Químicos del Agua/aislamiento & purificación
20.
Lepr Rev ; 86(3): 213-9, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26665356

RESUMEN

This study was done to compare the changes in plantar load (weight distribution) and gait patterns before and after tibialis posterior transfer surgery in people affected by leprosy. Changes in gait patterns were observed and proportionate changes in plantar load were quantified using data captured by a baropodometer. All the eight patients who underwent tibialis posterior transfer surgery in 2013 in our hospital were included in the study. In addition to the regular pre-operative and post-operative assessments, the patients also underwent baropodometric evaluation. There was a significant change in plantar load at the heel, lateral border and forefoot. Using the foot pressure scan, it was noted that the progression of the centre of mass (displayed graphically as 'the gait line') was also affected by the altered pattern of weight distribution. This study reiterates the importance of tibialis posterior transfer because: it restores the normal gait pattern of 1, 2, 3 (where 1 is heel strike, 2 is mid foot contact and 3 is forefoot contact) and provides a more uniform distribution of planter load.


Asunto(s)
Trastornos Neurológicos de la Marcha/etiología , Trastornos Neurológicos de la Marcha/cirugía , Marcha/fisiología , Lepra/complicaciones , Soporte de Peso , Adolescente , Adulto , Anciano , Humanos , Masculino , Persona de Mediana Edad , Modalidades de Fisioterapia
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