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1.
Int J Biol Macromol ; 258(Pt 2): 129007, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38151082

RESUMEN

The excellent comprehensive properties of microfiber synthetic leathers have led to their wide application in various aspects of our lives. However, the issue of flammability remains a significant challenge that needs to be addressed. Nowadays, the bio-based chemicals used in the flame-retardant materials have extremely grabbed our eyes. Herein, we developed an ecologically friendly flame-retardant microfiber synthetic leather using phosphorus-free layer-by-layer assembly technology (LBL) based on natural polysaccharide alginate (SA) coupled with polyethyleneimine (PEI) and 3-aminopropyltriethoxysilane (APTES). The effect of different LBL coating systems on the flame retardancy of microfiber synthetic leather was investigated. The results demonstrated that the introduction of APTES can completely inhibit the melt-dripping by enhancing char formation through silica elements. Furthermore, the trinary coating system consisting of SA/APTES/PEI exhibited excellent flame retardancy by combining gas-phase action from PEI and condensed-phase function from APTES. This modified microfiber synthetic leather showed a significantly higher limiting oxygen index (LOI) value of 33.0 % with no molten droplet. Additionally, the SA-based coating slightly suppressed the heat release, resulting in a 20 % reduction in total heat release during the combustion test. Overall, this work presents a facile and environmentally-friendly approach for achieving flame-retardant and anti-dripping microfiber synthetic leather.


Asunto(s)
Alginatos , Retardadores de Llama , Propilaminas , Silanos , Epidermis , Ojo , Fósforo , Polietileneimina
2.
Int J Biol Macromol ; 258(Pt 2): 129037, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38158061

RESUMEN

The present work systematically investigated the influence of starch silylation on the structures and properties of starch/epoxidized soybean oil-based bioplastics. Silylated starch was synthesized using starch particles (SP-ST) or gelatinized starch (SG-ST) under different silane hydrolysis pHs. Due to the appearance of -NH2 groups and lower OH wavenumbers, SP-ST obtained at pH 5 showed higher silylation degree and stronger hydrogen bond interaction with epoxidized soybean oils (ESO) than that at pH 11. The morphology analysis revealed better interfacial compatibility of ESO and SP-ST. The tensile strength of the samples containing SP-ST increased by 51.91 % than the control, emphasizing the enhanced interaction within the bioplastics. However, tensile strength of the bioplastics with SG-ST decreased by 59.56 % due to their high moisture contents from unreacted silanes. Additionally, the bioplastics with SG-ST exhibited an obvious reduction of thermal stability and an increase in water solubility because of the presence of unreacted APMS. The bioplastic degradation was not prevented by starch silylation except high pH. The bioplastics showed the most desirable tensile properties, thermal stability, and water solubility when starch was surface-modified with silanes hydrolyzed at pH 5. These outcomes made the fabricated bioplastics strong candidates for petroleum-based plastics for packaging applications.


Asunto(s)
Aceite de Soja , Almidón , Aceite de Soja/química , Almidón/química , Silanos , Agua/química
3.
Photodiagnosis Photodyn Ther ; 43: 103693, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37419190

RESUMEN

AIMS: To evaluate the impact of various pretreatment regimes (LLLT, Ti-sapphire laser, CO2, and HFA-S) on hybrid ceramics, specifically focusing on their ability to enhance repair strength and minimize surface roughness (Ra). MATERIAL AND METHODS: Discs were made from hybrid ceramics and after disinfection were randomly divided into four groups based on different surface conditioning techniques. Each group consisted of 15 discs, resulting in a total sample size of 60. dics in group 1 was surface treated with Low-level laser therapy (LLLT) using methylene blue (MB), Discs in group 2 with Ti-sapphire laser, Discs in group 3 with CO2 laser, and discs in group 4 with HFA-S. Five samples from each group were assessed for Ra. The remaining 10 samples from each group underwent repair using a porcelain repair kit in adherence to the planned instructions. The bond strength of each sample in all groups was measured using a universal testing machine. Following the bond strength testing, the specimens from all study groups were analyzed to determine the mode of failure. To evaluate the data, a two-way analysis of variance (ANOVA) was used, followed by post hoc multiple comparisons. RESULTS: The highest repair bond strength was observed in group 4 hybrid ceramics pretreated with HFA-S (19.05±0.79 MPa). The lowest repair bond scores were observed in group 1 hybrid ceramics preconditioned with LLLT in the presence of Photosensitizer (13.41±0.36 MPa). The highest Ra scores were exhibited in group 2 surface treated with Ti-sapphire laser (0.0515±0.16 µm) and the lowest Ra scores were observed in Group 4 HFA-S (0.0311±0.79 µm). Predominant bond failure among different investigated groups was cohesive. CONCLUSION: The current gold standard for hybrid ceramic conditioning is the use of hydrofluoric acid (HFA) combined with a silane coupling agent. Low-level laser therapy with methylene blue photosensitizer is not recommended for the treatment of hybrid ceramics.


Asunto(s)
Láseres de Gas , Terapia por Luz de Baja Intensidad , Fotoquimioterapia , Dióxido de Carbono , Azul de Metileno , Propiedades de Superficie , Fármacos Fotosensibilizantes , Resistencia al Corte , Titanio , Fotoquimioterapia/métodos , Óxido de Aluminio , Láseres de Gas/uso terapéutico , Cerámica/química , Ácido Fluorhídrico/química , Silanos/química , Ensayo de Materiales
4.
J Org Chem ; 88(13): 8505-8511, 2023 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-37285506

RESUMEN

A boronic acid catalyzed carbon-carbon and carbon-nitrogen bond-forming reaction for the functionalization of various π-activated alcohols has been developed. Ferrocenium boronic acid hexafluoroantimonate salt was identified as an effective catalyst in the direct deoxygenative coupling of alcohols with a variety of potassium trifluoroborate and organosilane nucleophiles. In a comparison between these two classes of nucleophiles, the use of organosilanes leads to higher reaction yields, increased diversity of the alcohol substrate scope, and high E/Z selectivity. Furthermore, the reaction proceeds under mild conditions and yields up to 98%. Computational studies provide a rationalization for a mechanistic pathway for the retention of E/Z stereochemistry when E or Z alkenyl silanes are used as nucleophiles. This methodology is complementary to existing methodologies for deoxygenative coupling reactions involving organosilanes, and it is effective with a variety of organosilane nucleophile sub-types, including allylic, vinylic, and propargylic trimethylsilanes.


Asunto(s)
Boratos , Silanos , Carbono , Ácidos Borónicos , Estructura Molecular , Catálisis , Etanol , Nitrógeno
5.
Carbohydr Polym ; 300: 120253, 2023 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-36372510

RESUMEN

In this work, a systematic coupling study of silane coupling agent between starch and epoxidized soybean oils (ESO) was carried out. Starch was modified by 3-aminopropyl trimethoxy silane (APMS) with various contents of NaOH. The APMS-modified starch was incorporated with ESO to synthesize the bioplastics by solution casting. As demonstrated by the FTIR spectra, the hydrogen bond interactions among starch molecules were inhibited by the modification. This outcome provided higher interaction and compatibility of starch with ESO, as confirmed by FESEM. TGA showed that the thermal stability of starch decreased considerably after the silylation. In contrast, the produced bioplastics with silylated starch exhibited higher thermal stability than the control sample. Regarding the bioplastics, an obvious increase of tensile strength from 5.78 MPa to 9.29 MPa was obtained. This work suggested a simple and effective modification technique by APMS to improve compatibility of starch/ESO-based bioplastics with superior mechanical and thermal properties.


Asunto(s)
Manihot , Aceite de Soja , Aceite de Soja/química , Manihot/química , Silanos , Almidón/química , Resistencia a la Tracción
6.
Oper Dent ; 47(5): 574-584, 2022 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-36121727

RESUMEN

OBJECTIVE: To investigate the effect of sandblasting with fluorapatite glass-ceramic (FGC) powder on zirconia surface roughness, crystallinity, and shear bond strength (SBS) of indirect repairing composite to zirconia using different primers/adhesives. METHODS: Zirconia blocks were treated as follows: no treatment (control group), blasting with 30-µm silica-coated alumina (CoJet group), and blasting with FGC powder (FGC group). The surface topography, silica content, roughness, and crystallinity of treated zirconia surfaces were analyzed by a scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), an optical profilometer, and X-ray diffraction (XRD), respectively. Four primers/adhesives (Monobond Plus, Calibra Silane, Futurabond M+, and Scotchbond Universal) were compared to bond precured resin composite to zirconia groups using Multilink Automix resin cement. Bonded specimens were thermocycled for 10,000 cycles and tested in SBS and the modes of failure were recorded. The effect of different surface treatments and primers/adhesives on SBS results were statistically analyzed using two-way ANOVA and Bonferroni post-hoc tests (α=0.05). RESULTS: Both CoJet and FGC groups showed rough surfaces with a higher content of silica in FGC, but less monoclinic crystals, compared to the CoJet group. The highest mean SBS was found in the FGC group treated with Monobond Plus compared to CoJet and Control groups. Adhesive failure was predominant in control groups, while combined failure was found in the CoJet and FGC groups regardless of the primers/adhesives employed. CONCLUSION: Sandblasting zirconia with FGC powder increased SBS of resin composite to zirconia with lower monoclinic phase transformation compared to CoJet sand. Monobond Plus reported the highest means of SBS values compared to other primers/adhesives.


Asunto(s)
Recubrimiento Dental Adhesivo , Cementos de Resina , Óxido de Aluminio , Apatitas , Cerámica/química , Cerámica/uso terapéutico , Resinas Compuestas/química , Recubrimiento Dental Adhesivo/métodos , Cementos Dentales/química , Ensayo de Materiales , Polvos , Cementos de Resina/química , Cementos de Resina/uso terapéutico , Arena , Resistencia al Corte , Silanos , Dióxido de Silicio/química , Propiedades de Superficie , Circonio/química
7.
Int J Biol Macromol ; 219: 213-223, 2022 Oct 31.
Artículo en Inglés | MEDLINE | ID: mdl-35907460

RESUMEN

This study highlights the potential use of cellulose nanocrystals (CNCs) from kenaf fiber as a dominant phase for aerogel application. CNCs were modified with methyltrimethoxysilane (MTMS) using the sol-gel method and bound with gamma-irradiated cross-linked gelatin. The properties of the aerogel were studied using Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), and water contact angle (WCA). Compression and oil absorption tests were performed to study the aerogels' mechanical and oil absorption properties. A decrease in the OH peak and improved hydrophobicity of CNCs in CNC-MTMS suggested the successful grafting of MTMS onto CNCs, as shown in the FTIR and WCA analyses. Several absorption peaks in the FTIR spectrum shifted, disappeared, or reduced, implying a formation of crosslink between gelatin molecules and hydrogen bonding between CNC and gelatin. FESEM micrographs showed well-organized pores in the gamma-irradiated aerogel, which contribute to increased compressive strength. The oil absorption test indicated that gamma-irradiated CNC-MTMS/gelatin could be a good oil absorbent. Furthermore, this aerogel showed good reusability, where only 4 % of crude oil absorption reduction occurred by the eighth cycle. The combined properties of these aerogel materials can provide good mechanical and oil absorption performance.


Asunto(s)
Nanopartículas , Petróleo , Celulosa/química , Gelatina , Geles/química , Interacciones Hidrofóbicas e Hidrofílicas , Nanopartículas/química , Silanos , Agua/química
8.
Int J Biol Macromol ; 209(Pt A): 1248-1259, 2022 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-35461872

RESUMEN

Silane-treated natural cellulosic Kigelia africana fruit fibre (KAF) was experimentally established to have strong strength after removing hydrophilic materials. Silane treatment makes it compatible with hydrophobic biopolymeric materials than existing non-grafted KA fibre. In this work, the polysaccharide was extracted from the KAF and found to have all the essential compounds. KA fruit-based cellulosic fibre was extracted and treated with different concentrations of silane solution. Silane-treated (13%) KAF has a cellulose content of about 76.86%. The peak found at 1734 cm-1 shows the hemicellulose in untreated fibres, and its intensity decreased after silane treatment, as confirmed by FTIR. X-ray diffraction investigation indicated that silane-treated (5%) KAF has a crystallinity index of 70.22%. After treatment, the tensile strength of 5% silane-treated KAF shows a tensile strength of 490.77 MPa, giving more viability to biofibre reinforcement.


Asunto(s)
Frutas , Silanos , Celulosa/química , Frutas/química , Polisacáridos/química , Silanos/química , Resistencia a la Tracción
9.
Sci Rep ; 12(1): 6354, 2022 04 15.
Artículo en Inglés | MEDLINE | ID: mdl-35428859

RESUMEN

Silane-based/fully hydrolyzed, endodontic irrigant exhibiting antimicrobial properties, is prepared, and is hypothesized to control macrophage polarization for tissue repair. Albino wistar rats were injected with 0.1 ml root canal irrigant, and bone marrow cells procured. Cellular mitochondria were stained with MitoTracker green along with Transmission Electron Microscopy (TEM) performed for macrophage extracellular vesicle. Bone marrow stromal cells (BMSCs) were induced for M1 and M2 polarization and Raman spectroscopy with scratch assay performed. Cell counting was used to measure cytotoxicity, and fluorescence microscopy performed for CD163. Scanning Electron Microscopy (SEM) was used to investigate interaction of irrigants with Enterococcus faecalis. K21 specimens exhibited reduction in epithelium thickness and more mitochondrial mass. EVs showed differences between all groups with decrease and increase in IL-6 and IL-10 respectively. 0.5%k21 enhanced wound healing with more fibroblastic growth inside scratch analysis along with increased inflammation-related genes (ICAM-1, CXCL10, CXCL11, VCAM-1, CCL2, and CXCL8; tissue remodelling-related genes, collagen 1, EGFR and TIMP-2 in q-PCR analysis. Sharp bands at 1643 cm-1 existed in all with variable intensities. 0.5%k21 had a survival rate of BMSCs comparable to control group. Bacteria treated with 0.5%k21/1%k21, displayed damage. Antimicrobial and reparative efficacy of k21 disinfectant is a proof of concept for enhanced killing of bacteria across root dentin acquiring functional type M2 polarization for ethnopharmacological effects.


Asunto(s)
Antiinfecciosos , Silanos , Animales , Antibacterianos/farmacología , Antiinfecciosos/farmacología , Biopelículas , Dentina , Enterococcus faecalis , Macrófagos , Modelos Animales , Irrigantes del Conducto Radicular/farmacología , Silanos/farmacología , Hipoclorito de Sodio/farmacología
10.
J Dent Res ; 101(7): 769-776, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35081830

RESUMEN

Durable resin-ceramic adhesion may influence the clinical success of ceramic restorations, which has been one of the challenging issues in dentistry. The present study assessed the bond strength and chemical interaction of 10-methacryloxydecyl dihydrogen phosphate (MDP), MDP+silane, and MDP-salt primers to alumina-blasted zirconia ceramic by tensile bond strength test, surface elemental composition with x-ray photoelectron spectroscopy analysis, contact angle measurement, surface morphology with scanning electron microscopy, and surface topography with 3-dimensional confocal laser scanning microscope analyses. MDP-salt showed the highest tensile bond strength before and after thermocycling when compared with MDP and MDP+silane (P < 0.05). The measured contact angle values differed significantly (P < 0.001) in the order of MDP-salt > control (no chemical pretreatment) > MDP+silane > MDP. There was no difference in surface roughness (P = 0.317) and surface topography among all tested groups. Zirconia treated with MDP-salt showed phosphorus peaks in addition to zirconia and alumina peaks. MDP-salt has zirconia priming properties, which improves bonding performance to resin cement.


Asunto(s)
Recubrimiento Dental Adhesivo , Sales (Química) , Óxido de Aluminio , Recubrimiento Dental Adhesivo/métodos , Ensayo de Materiales , Metacrilatos/química , Cementos de Resina/química , Resistencia al Corte , Silanos/química , Propiedades de Superficie , Circonio/química
11.
J Prosthodont Res ; 66(3): 491-501, 2022 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-34853249

RESUMEN

PURPOSE: The investigation of zirconia core surface pretreatments on the flexural strength of bilayered zirconia ceramics before and after artificial accelerating aging. METHODS: Ninety bar-shaped specimens were manufactured from Yttria Stabilized Tetragonal Zirconia Polycrystal (Y-TZP) and divided in three groups depending on zirconia surface pretreatment before veneering: layering with liner, pretreatment with silane-containing gas flame (SGF) with the Silano-Pen device and alumina air-abrasion. Half of the veneered specimens in each group (n=15) underwent artificial accelerating aging. A 4-point bending test was performed to determine flexural strength. Three specimens from each group were further analyzed using Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) before veneering and after fracture (aged and non-aged subgroups). RESULTS: Alumina air-abrasion was correlated to increased phase transformation from tetragonal to monoclinic zirconia phase. Qualitative analysis revealed that with the majority of the specimens pretreated with the silane-containing gas flame, areas of the veneering material remained firmly attached to the zirconia core after flexural strength testing. There was no statistically significant difference on the flexural strength among the groups before or after aging. Artificial accelerating aging resulted in statistically significant higher flexural strength of the specimens after aging. CONCLUSION: SGF pretreatment can be an acceptable and feasible alternative method before the veneering of Y-TZP zirconia as it presented slightly higher bond strength compared with alumina air-abrasion which was associated with higher tetragonal to monoclinic (t→m) phase transformation. Accelerating aging leads to an increase of the mechanical properties under in vitro conditions.


Asunto(s)
Resistencia Flexional , Silanos , Óxido de Aluminio/química , Cerámica/química , Materiales Dentales/química , Ensayo de Materiales , Propiedades de Superficie , Itrio/química , Circonio/química
12.
J Prosthet Dent ; 128(2): 139-149, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-33573835

RESUMEN

STATEMENT OF PROBLEM: Which surface treatment provides the optimal bond strength (BS) for the repair of resin nanoceramics (RNCs) and polymer-infiltrated ceramics (PICs) is unclear. PURPOSE: The purpose of this systematic review and meta-analysis of in vitro studies was to determine the best surface treatment protocols for the repair of PICs and RNCs. MATERIAL AND METHODS: The PubMed, Scopus, and Web of Science electronic databases were searched to select in vitro studies in English up to March 2020. Studies with fewer than 5 specimens, those that did not evaluate the BS of PICs or RNCs, and those with aging for fewer than 30 days and 5000 cycles were excluded. Data sets were extracted, and the mean differences were analyzed by using a systematic review software program. RESULTS: Among 284 potentially eligible studies, 21 were selected for full-text analysis, and 9 were included in the systematic review, of which 6 were used in the meta-analysis. The meta-analyses were performed for each treatment surface versus their respective control group and their combinations according to material: RNCs and PICs. For RNCs, airborne-particle abrasion with aluminum oxide (Al2O3) treatment was statistically higher than tribochemical silica airborne-particle abrasion (CoJet) (P=.02, I2=90%) and that in the hydrofluoric acid (HF) (P<.001, I2=0%) groups and was statistically similar to diamond rotary instrument grinding (P=.40, I2=54%). For PICs, the treatment with hydrofluoric acid (HF) was statistically significantly higher than with CoJet (P=.03, I2=62%) and airborne-particle abrasion with Al2O3 (P<.001, I2=98%). CONCLUSIONS: The best surface treatment protocol for repair varied according to the restorative material. HF followed by silanization is suggested for PICs, and airborne-particle abrasion with Al2O3 or preparation with a diamond rotary instrument for RNCs.


Asunto(s)
Recubrimiento Dental Adhesivo , Cementos de Resina , Óxido de Aluminio , Cerámica , Diamante , Ácido Fluorhídrico , Ensayo de Materiales , Polímeros , Silanos , Propiedades de Superficie , Circonio
13.
J Org Chem ; 87(1): 429-452, 2022 01 07.
Artículo en Inglés | MEDLINE | ID: mdl-34918517

RESUMEN

The copper-catalyzed reductive Ireland-Claisen rearrangement of propargylic acrylates led to 3,4-allenoic acids. The use of silanes or pinacolborane as stoichiometric reducing agents and triethylphosphite as a ligand facilitated the divergent and complementary selectivity for the synthesis of diastereomeric anti- and syn-rearranged products, respectively. Copper-catalyzed reductive Ireland-Claisen rearrangement of allylic 2,3-allenoates proceeded effectively only when pinacolborane was used as a reductant to generate various 1,5-dienes in excellent yields and with good diastereoselectivities in some cases. Mechanistic studies showed that the silyl and boron enolates, rather than the copper enolate, underwent a stereospecific rearrangement via a chairlike transition state to afford the corresponding Claisen rearrangement products.


Asunto(s)
Acrilatos , Cobre , Catálisis , Silanos , Estereoisomerismo
14.
Small ; 17(50): e2105273, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34741428

RESUMEN

Nanomaterials usually manifest unique properties in solutions but will be undermined in the solid state. It is necessary to incorporate them into substrates or hybrid them with other functional materials for multiple devices and applications. Though there are a variety of methods to inherit their intrinsic properties like fluorescent and mechanical performance, most nanohybrid materials would lose their transparency irreversibly when construct solid-state devices. As a hot topic of nanomaterials in recent years, scientific works found a type of carbon dots using silane coupling agents as precursors that can overcome the shortcoming. These carbon dots, called silane-functionalized carbon dots (SiCDs), are catching increasing interest due to their versatility. Silane coupling agents endow SiCDs with the ability to disperse in solvents or polymerize with matrices by blending or covalent bonds without loss of transparency and decline of performance. The distinguishing features make SiCDs an ideal high transmittance, high doping concentration nanomaterial. The synergistic effect of SiCDs and hybridized sol-gel solid structures can not only hold the optical features of CDs but also enhance their original physical and chemical performance. This highlight focuses on the connection between SiCDs and organosilanes. Plus, preparation methods, applications, and prospective of SiCDs are mentioned.


Asunto(s)
Carbono , Puntos Cuánticos , Terapia Biológica , Estudios Prospectivos , Silanos
15.
Carbohydr Polym ; 272: 118450, 2021 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-34420712

RESUMEN

One of the well-recognized weaknesses of starch-based materials is their sensitivity to moisture, which limits their expanding applications. Natural materials, soyabean oils have been used as a coating for starch film, but the poor interface between hydrophilic starch and hydrophobic soyabean oil needs to be improved. In this work, (3-Aminopropyl) triethoxysilane (APTES) was used to reinforce the bonding between starch matrix and the coating of bio-based acrylated epoxidized soyabean oil (AESO). Study results show that APTES interacted effectively with both starch films via hydrogen bonding, and chemical bonds with AESO through the Michael addition reaction. Pull adhesion and cross-cutting tests demonstrated that the interfacial adhesion was significantly improved after treating their surface with APTES. The interfacial adhesion strength increased over 4 times after treating with 1.6 wt% APTES. The starch films treated with APTES and AESO coating were intact after soaking in water for more than 2 h.


Asunto(s)
Interacciones Hidrofóbicas e Hidrofílicas , Propilaminas/química , Silanos/química , Aceite de Soja/química , Almidón/química , Enlace de Hidrógeno , Microscopía Electrónica de Rastreo/métodos , Permeabilidad , Espectroscopía de Fotoelectrones/métodos , Aceites de Plantas/química , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Agua/química
16.
Chem Asian J ; 16(15): 2018-2021, 2021 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-34109742

RESUMEN

In this study, we report an efficient fabrication method for the membrane of a metal-organic framework (MOF) (Kgm-OEt) which is one kind of kagomé-type MOF with a two-dimensional (2D) sheet structure having one-dimensional (1D) channels suitable for separation of H2 from other larger gases. The Kgm-OEt seed layer was created on an Al2 O3 substrate using layer-by-layer (LBL) growth, then a membrane was fabricated by secondary growth. The membrane on a 3-aminopropyltriethoxysilane (APTEs)-treated substrate obtained in this method was continuous and defect-free with the crystal orientation suitable for gas transportation, while the membrane grown on an unmodified substrate was loosely packed with unfavorable crystal orientation.


Asunto(s)
Óxido de Aluminio/química , Estructuras Metalorgánicas/síntesis química , Propilaminas/química , Silanos/química , Estructuras Metalorgánicas/química , Estructura Molecular , Tamaño de la Partícula , Porosidad , Propiedades de Superficie
17.
Int J Mol Sci ; 22(9)2021 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-33946213

RESUMEN

In the following study, ground plum stones and silanized ground plum stones were used as natural fillers for novel polyurethane (PUR) composite foams. The impact of 1, 2, and 5 wt.% of fillers on the cellular structure, foaming parameters, and mechanical, thermomechanical, and thermal properties of produced foams were assessed. The results showed that the silanization process leads to acquiring fillers with a smoother surface compared to unmodified filler. The results also showed that the morphology of the obtained materials is affected by the type and content of filler. Moreover, the modified PUR foams showed improved properties. For example, compared with the reference foam (PUR_REF), the foam with the addition of 1 wt.% of unmodified plum filler showed better mechanical properties, such as higher compressive strength (~8% improvement) and better flexural strength (~6% improvement). The addition of silanized plum filler improved the thermal stability and hydrophobic character of PUR foams. This work shows the relationship between the mechanical, thermal, and application properties of the obtained PUR composites depending on the modification of the filler used during synthesis.


Asunto(s)
Poliuretanos/química , Prunus domestica/química , Silanos/química , Técnicas de Química Sintética , Fuerza Compresiva , Materiales de Construcción , Ensayo de Materiales , Poliuretanos/síntesis química , Porosidad , Reología , Silanos/síntesis química
18.
J Nanosci Nanotechnol ; 21(11): 5688-5693, 2021 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-33980381

RESUMEN

Even with all the recent technological improvements, cancer remains to be the disease with the highest impact on global health. Due to obviously disadvantages or limitations on traditional therapy, researchers are engaged to search for safely and effective methods in cancers' therapy. Photothermal therapy (PTT) has been employed in treating cancers and several of other diseases. In this study, novel thermosensitive and targeting nanoparticle, C225-silane-F127/gold nanorod (C-SFGR) combined with PTT was investigated in EGFR-overexpressing xenografts mice model. For better light to heat transformation exposed with 808 nm near-infrared (NIR) laser, the diameter of thermosensitive C-SFGR was designed at about 120 nm. To address the biocompatibility, the viability of A549 cell line was greater than 80% under high concentrations of C-SFGR (1,000 µg/mL), indicating its low cytotoxicity. After intravenous injection of C-SFGR and combined with NIR treatment for 2 min in A549 bearing mice, tumors were almost completely shriveled after 2 weeks. For developing as theranostic agent, C-SFGR was then labeled with 67Ga, with radiochemical purity over 98%. These present results suggest that C-SFGR could be also applied as a SPECT-imaging agent and as an effective antitumor agent.


Asunto(s)
Hipertermia Inducida , Nanotubos , Animales , Línea Celular Tumoral , Oro , Ratones , Fototerapia , Terapia Fototérmica , Polietilenos , Polipropilenos , Silanos/toxicidad
19.
Sci Total Environ ; 771: 144764, 2021 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-33736157

RESUMEN

Heavy metals like Cr (VI), when released into the environment, pose a serious threat to animal and human health. In this study, iron and (3-Aminopropyl)triethoxysilane (APTES) biochar composites were prepared from the biochar, which was produced through the pyrolysis of rice straw at 400 and 600 °C, using the chemical processes with an aim that the doping of pristine biochar structure with the Fe and NH2 radicals would enhance the removal of Cr (VI) and Zn (II) adsorption in both aqueous solution and soil. Both biochar composites were mixed at a rate of 3% (w/w) with the mine soil for the soil incubation test, and after completion of the test, a soil fertility index (SFI) was calculated. Results showed that both iron and APTES biochar composites followed the Langmuir-Freundlich isotherm showing the maximum removal capacity of 100.59 mg/g for Cr (VI) by APTES/SiBC 600 and maximum adsorption capacity of 83.92 mg/g for Zn2+ by Fe/BC 400. The SFI of the mine-soil amended with both Fe and APTES biochar composites were 16.67 and 13.04%, respectively higher than the controlled study. The mitotic index of the A. cepa cells that grew up in the soil amended with Fe/BC and APTES/SiBC were 40.47 and 44.45%, respectively, higher than the controlled study. The results indicated that the incorporation of the Fe and APTES biochar composites in the soil effectively reduced the metal toxicity and improved the soil physicochemical properties. This study opens up the prospects of using biochar composites in contaminated soil and water treatments.


Asunto(s)
Metales Pesados , Oryza , Contaminantes del Suelo , Adsorción , Carbón Orgánico , Humanos , Hierro , Metales Pesados/análisis , Extractos Vegetales , Propilaminas , Silanos , Suelo , Contaminantes del Suelo/análisis , Zinc
20.
Mikrochim Acta ; 187(9): 535, 2020 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-32870397

RESUMEN

An innovative ultrasensitive electrochemical aptamer-based sensor was developed for ochratoxin A (OTA) detection in cold brew coffee through revolutionary combination of nanofibers, electrochemical method, and aptamer technologies. The assembly of the aptasensor was based on the activation of silanized cellulose nanofibrous membranes as a supporting matrix for methylene blue (MB) redox probe-labeled aptamer tethering. Cellulose nanofibrous membranes were regenerated by deacetylating electrospun cellulose acetate nanofibrous membranes with deacetylation efficacy of 97%, followed by silanization of the nanofiber surfaces by using (3-aminopropyl)triethoxysilane (APTES). A replacement of conventionally casted membranes by the nanofibrous membranes increased the active surface area on the working electrode of a screen-printed three-electrode sensor by more than two times, consequently enhancing the fabricated aptasensor performance. The developed aptasensor demonstrated high sensitivity and specificity toward OTA in a range 0.002-2 ng mL-1, with a detection limit of 0.81 pg mL-1. Moreover, the assembled aptamer-based sensor successfully detected OTA in cold brew coffee samples without any pretreatment. The aptasensor exhibited good reusability and stability over long storage time. Graphical abstract.


Asunto(s)
Aptámeros de Nucleótidos/química , Técnicas Biosensibles/métodos , Celulosa/química , Técnicas Electroquímicas/métodos , Nanofibras/química , Ocratoxinas/análisis , Café/química , Contaminación de Alimentos/análisis , Ácidos Nucleicos Inmovilizados/química , Límite de Detección , Azul de Metileno/química , Ocratoxinas/química , Oxidación-Reducción , Propilaminas/química , Silanos/química
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