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1.
Langmuir ; 40(9): 4966-4977, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38393830

RESUMO

Utilizing metal-organic framework (MOF) materials for the extraction of bromide ions (Br-) from aqueous solutions, as an alternative to chlorine gas oxidation technology, holds promising potential for future applications. However, the limitations of powdered MOFs, such as low utilization efficiency, ease of aggregation in water, and challenging recovery processes, have hindered their practical application. Shaping MOF materials into application-oriented forms represents an effective but challenging approach to address these drawbacks. In this work, a novel Ag-UiO-66-(OH)2@delignified wood cellulose aerogel (CA) adsorbent is synthesized using an oil bath impregnation method, involving the deposition of UiO-66-(OH)2 nanoparticles onto CA and the uniform dispersion of Ag0 nanoparticles across its surface. CA, characterized by the intertwined cellulose nanofiber structure and a highly hydrophilic surface, serves as an ideal substrate for the uniform growth of UiO-66-(OH)2 nanoparticles, which, in turn, spontaneously reduce Ag+ to form distributed Ag0 nanoparticles due to the abundant hydroxyl groups provided. Leveraging the well-defined biological structure of CA, which offers excellent mass transfer channels, and the highly dispersed Ag adsorption sites, Ag-UiO-(OH)2/CA exhibits remarkable adsorption capacity (642 mg/gAg) under optimized conditions. Furthermore, an integrated device is constructed by interconnecting Ag-UiO-(OH)2/CA adsorbents in series, affirming its potential application in the continuous recovery of Br-. This study not only presents an efficient Ag-UiO-(OH)2/CA adsorbent for Br- recovery but also sheds light on the extraction of other valuable elements from various liquid ores.

2.
Int J Mol Sci ; 20(1)2018 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-30577498

RESUMO

The modification of the surface of silica gel to prepare hydrophilic chromatographic fillers has recently become a research interest. Most researchers have grafted natural sugar-containing polymers onto chromatographic surfaces. The disadvantage of this approach is that the packing structure is singular and the application scope is limited. In this paper, we explore the innovative technique of grafting a sugar-containing polymer, 2-gluconamidoethyl methacrylamide (GAEMA), onto the surface of silica gel by atom transfer radical polymerization (ATRP). The SiO2-g-GAEMA with ATRP reaction time was characterized by Fourier infrared analysis, Thermogravimetric analysis (TGA), and elemental analysis. As the reaction time lengthened, the amount of GAEMA grafted on the surface of the silica gel gradually increased. The GAEMA is rich in amide bonds and hydroxyl groups and is a typical hydrophilic chromatography filler. Finally, SiO2-g-GAEMA (reaction time = 24 h) was chosen as the stationary phase of the chromatographic packing and evaluated with four polar compounds (uracil, cytosine, guanosine, and cytidine). Compared with unmodified silica gel, modified silica gel produces sharper peaks and better separation efficiency. This novel packing material may have a potential for application with highly isomerized sugar mixtures.


Assuntos
Cromatografia , Polímeros , Sílica Gel , Acrilamidas/química , Cromatografia/métodos , Interações Hidrofóbicas e Hidrofílicas , Polimerização , Polímeros/química , Sílica Gel/química , Dióxido de Silício/química , Espectroscopia de Infravermelho com Transformada de Fourier , Termogravimetria
3.
Polymers (Basel) ; 16(7)2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38611239

RESUMO

The current work introduces the synthesis of inorganic salt nano/micro-crystals during the reduction of hydrogen tetrachloroaurate(III) by Pluronic triblock copolymers (P123, PEO20-PPO70-PEO20). The morphologies and component were confirmed using an electron microscope with an electronic differential system (EDS), and the crystal structures were determined with X-ray diffraction (XRD). The morphologies highly depend on the concentrations of Pluronic and pH values. The mean size of the nanocrystal and hollow micro-crystal were controlled typically in the range of 32-150 nm (side length) and 1.4 µm, respectively. Different from the electrospray-ionization (EI) method, a model in which KCl forms a supersaturated solution in the micellar core of Pluronic is used to explain the formation process. This work provides the new insight that inorganic salt nanocrystals could be synthesized with the template of micelles in pure aqueous solutions.

4.
Membranes (Basel) ; 13(3)2023 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-36984643

RESUMO

Acid saccharification of hemicelluloses offers promising pathways to sustainably diversify the revenue of the lignocellulose biorefinery industry. Electrodialysis to separate inorganic acids from acid hydrolysate in the hemicellulose saccharification process could realize the recovery of sulfuric acid, and significantly reduced the chemical consumption than the traditional ion exchange resins method. In this work, the deacidification of corncob acid hydrolysate was conducted by a homemade electrodialysis apparatus. The results showed that: (1) more than 99% of acid can be removed through the electrodialysis process; (2) A non-negligible membrane fouling occurred during the electrodialysis process, which aggravated with the repeated batch running The final global system resistance rose from 15.8 Ω (1st batch) to 43.9 Ω (10th batch), and the treatment ending time was delayed from 120 min (1st batch) to 162 min (10th batch); (4) About 90% of protein, 70% of ferulate acid, and 80% of p-coumarate acid precipitated from the corncob acid hydrolysate during the electrodialysis process. The zeta potential of corncob acid hydrolysate changed from a positive value to a negative value, and an isoelectric point around pH 2.3 was reached. HSQC, FTTR, and GPC, along with SEM and EDS analysis, revealed that the fouling layers mostly consisted of hydrolysates of protein and lignin. The result of HSQC indicated that the membrane foulant may exist in the form of lignin-carbohydrate complexes, as the lignin component of the membrane foulant is in the form of p-coumarate and ferulate. From the result of FTIR, a strong chemical bonding, such as a covalent linkage, existed between the lignin and protein in the membrane foulant. Throughout the electrodialysis process, the increased pH decreased the stability of colloidal particles, including lignin and proteins. Destabilized colloidal particles started to self-aggregate and form deposits on the anion exchange membrane's surface. Over time, these deposits covered the entire membrane surface and the spaces between the membranes. Eventually, they attached to the surface of the cation exchange membrane. In the end, a suggestion to control and minimize membrane fouling in this process was discussed: lower pH as a process endpoint and a post-treatment method.

5.
Biomed Mater ; 18(4)2023 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-37321227

RESUMO

This work aimed to establish a simple and feasible method to obtain silk fibroin nanoparticles (SFNPs) with uniform particles size, and then modify the SFNPs with nanobody (Nb) 11C12 targeting the proximal membrane end of carcinoembryonic antigen on the surface of colorectal cancer (CRC) cells. The regenerated silk fibroin (SF) was isolated using ultrafiltration tubes with a 50 kDa molecular weight cut-off, and the retention fraction (named as SF > 50 kDa) was further self-assembled into SFNPs by ethanol induction. Scanning electron microscope (SEM) and high-resolution transmission electron microscop showed that the SFNPs with uniform particles size were formed. Due to electrostatic adsorption and pH responsiveness, SFNPs have been proved to effectively load and release the anticancer drug doxorubicin hydrochloride (DOX) (DOX@SFNPs). Further, targeting molecule Nb 11C12 was used to modify these nanoparticles, constituting the targeted outer layer of the drug delivery system (DOX@SFNPs-11C12), achieving precise localization to cancer cells. The release amount of DOX observed fromin vitrodrug release profiles increased as follows: pH 7.4 < pH 6.8 < pH 5.4, demonstrating that the DOX release could be accelerated in a weakly acidic environment.In vitrocytotoxicity experiments displayed that SFNPs-11C12 nanoparticles exhibited good safety and biocompatibility. Drug-loaded nanoparticles, DOX@SFNPs-11C12, led to higher LoVo cells apoptosis compared to DOX@SFNPs. Fluorescence spectrophotometer characterization and confocal laser scanning microscopy further showed that the internalization of DOX was highest in the DOX@SFNPs-11C12, certifying that the introduced targeting molecule enhanced the uptake of drug delivery system by LoVo cells. This study provides a simple and operational approach to developing an optimized SFNPs drug delivery system modified by targeting Nb, which can be a good candidate for CRC therapy.


Assuntos
Antineoplásicos , Neoplasias Colorretais , Fibroínas , Nanopartículas , Humanos , Fibroínas/química , Antígeno Carcinoembrionário , Nanopartículas/química , Doxorrubicina/farmacologia , Sistemas de Liberação de Medicamentos , Concentração de Íons de Hidrogênio
6.
Adv Mater ; 32(43): e2003553, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32954573

RESUMO

Liquid metal nanodroplets not only share similar metallic properties and nanoscale effect with solid metal nanoparticles, but also possess the additional uniqueness in nonvolatile fluidity and ambient sintering ability into continuous conductors. In most cases, liquid metal nanodroplets are encapsulated into ultrathin and fragile shells of oxides and amphiphile monolayers, and may be hindered from incorporating homogeneously into various composites through conventional processing methods. In this study, ring-opening polymerization is found to be initiated by sonicating the liquid metal EGaIn in fluidic lactones. By this in situ polymerization, EGaIn nanodroplets are encapsulated into polylactone shells with tunable thickness, which can further be dried into a solid powder. Besides high chemical stability and dispersibility in organic solvents, the powder of the EGaIn capsules combines the exceptional properties of the EGaIn droplets (e.g., photothermal effect) and the polylactone shells (e.g., biocompatibility, biodegradability, and compatibility with different polymer matrixes), being capable of being introduced into thermoplastic composites through liquid casting and thermal- or photomolding for the notch-insensitive tearing property, sintering-induced electric conductivity, and photothermal effect. Thus, the EGaIn initiator of ring-opening polymerization may start a pathway to produce stable andthermal/photomoldable powders of EGaIn capsules and their multifunctionalcomposites, applicable in biomedicines, soft electronics, and smart robots.

7.
Front Chem ; 8: 269, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32411660

RESUMO

With the development and prosperity of the global economy, the emission of carbon dioxide (CO2) has become an increasing concern. Its greenhouse effect will cause serious environmental problems, such as the global warming and climate change. Therefore, the worldwide scientists have devoted great efforts to control CO2 emissions through various strategies, such as capture, resource utilization, sequestration, etc. Among these, the catalytic conversion of CO2 to methane is considered as one of the most efficient routes for resource utilization of CO2 owing to the mild reaction conditions and simple reaction device. Pioneer thermodynamic studies have revealed that low reaction temperature is beneficial to the high catalytic activity and CH4 selectivity. However, the low temperature will be adverse to the enhancement of the reaction rate due to kinetic barrier for the activation of CO2. Therefore, the invention of highly efficient catalysts with promising low temperature activities toward CO2 methanation reaction is the key solution. The Ni based catalysts have been widely investigated as the catalysts toward CO2 methanation due to their low cost and excellent catalytic performances. However, the Ni based catalysts usually perform poor low-temperature activities and stabilities. Therefore, the development of highly efficient Ni based catalysts with excellent low-temperature catalytic performances has become the research focus as well as challenge in this field. Therefore, we summarized the recent research progresses of constructing highly efficient Ni based catalysts toward CO2 methanation in this review. Specifically, the strategies on how to enhance the catalytic performances of the Ni based catalysts have been carefully reviewed, which include various influencing factors, such as catalytic supports, catalytic auxiliaries and dopants, the fabrication methods, reaction conditions, etc. Finally, the future development trend of the Ni based catalysts is also prospected, which will be helpful to the design and fabrication of the Ni catalysts with high efficiency toward CO2 methanation process.

8.
J Colloid Interface Sci ; 363(2): 481-9, 2011 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-21855892

RESUMO

The influence of pH value on gold nanoparticle production in the presence of Pluronic stabilizers is systematically investigated. The reactions are studied as a function of pH and at fixed concentrations of the two reactants, HAuCl(4) and P123 block copolymer. Results indicate that the reaction pathway during the nanoparticle formation can be controlled by varying pH. The nanoparticles synthesized at pH=11.12 have an average diameter of 9.6 nm with a narrow size distribution, and the Pluronics are adsorbed on individual gold particle surfaces to form core-shell structures via hydrophobic interactions. The present work provides an economic way to improve the dispersion and stabilization of gold nanoparticles and throws further light on the understanding of gold nanoparticle production using block copolymers.


Assuntos
Ouro/química , Nanopartículas Metálicas/química , Polietilenoglicóis/química , Propilenoglicóis/química , Concentração de Íons de Hidrogênio , Luz , Tamanho da Partícula , Propriedades de Superfície , Água/química
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