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1.
Nanomaterials (Basel) ; 12(11)2022 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-35683702

RESUMO

The global turn from the linear to the circular economy imposes changes in common activities such as food packaging. The use of biodegradable materials such as polyvinyl alcohol, natural raw materials such as clays, and food byproducts such as chitosan to develop novel food packaging films attracts the interest of industrial and institutional research centers. In this study, novel hybrid nanostructures were synthesized via the growth of zinc oxide nanorods on the surface of two nanoclays. The obtained nanostructures were incorporated with chitosan/polyvinyl alcohol composite either as nanoreinforcement or as an active agent to develop packaging films. The developed films were characterized via XRD, FTIR, mechanical, water-vapor diffusion, water sorption, and oxygen permeability measurements. Antimicrobial activity measurements were carried out against four different pathogen microorganisms. XRD indicated the formation of an intercalated nanocomposite structure for both types of nanoclays. Furthermore, improved tensile, water/oxygen barrier, and antimicrobial properties were recorded for all films compared to the pure chitosan/polyvinyl alcohol film. Overall, the results indicated that the use of the bio-based developed films led to an extension of food shelf life and could be used as novel active food packaging materials. Among them, the most promising film was the 6% wt. ZnO@halloysite.

2.
Polymers (Basel) ; 14(9)2022 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-35567059

RESUMO

Herein, this work aims to fabricate well-ordered nanonetwork epoxy resin modified with poly(butyl acrylate)-b-poly(methyl methacrylate) (PBA-b-PMMA) block copolymer (BCP) for enhanced energy dissipation using a self-assembled diblock copolymer of polystyrene-b-poly(dimethylsiloxane) (PS-b-PDMS) with gyroid and diamond structures as templates. A systematic study of mechanical properties using nanoindentation of epoxy resin with gyroid- and diamond-structures after modification revealed significant enhancement in energy dissipation, with the values of 0.36 ± 0.02 nJ (gyroid) and 0.43 ± 0.03 nJ (diamond), respectively, when compared to intrinsic epoxy resin (approximately 0.02 ± 0.002 nJ) with brittle characteristics. This enhanced property is attributed to the synergic effect of the deliberate structure with well-ordered nanonetwork texture and the toughening of BCP-based modifiers at the molecular level. In addition to the deliberate structural effect from the nanonetwork texture, the BCP modifier composed of epoxy-philic hard segment and epoxy-phobic soft segment led to dispersed soft-segment domains in the nanonetwork-structured epoxy matrix with superior interfacial strength for the enhancement of applied energy dissipation.

3.
FEBS J ; 2022 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-35380736

RESUMO

An approach based on the combined use of saturation transfer difference (STD), Tr-NOESY and Inter-ligand NOEs for PHArmacophore Mapping (INPHARMA) NMR techniques and docking calculations is reported, for the first time, for mapping interactions and specific binding sites of caproleic acid (10 : 1 cis-9), oleic acid (18 : 1 cis-9), linoleic acid (18 : 2 cis-9,12) and linolenic (18 : 3, cis-9,12,15) free fatty acids (FFAs) with non-labelled serum albumin (BSA/HSA). Significant negative inter-ligand NOEs between the FFAs and the drugs ibuprofen and warfarin, through competition experiments, were observed. The inter-ligand NOEs and docking calculations were interpreted in terms of competitive binding mode, the significant folding of the bis allylic region and the presence of two orientations of the FFAs in the warfarin binding site (FA7), due to two potential distinctive anchoring polar groups of amino acids. This conformational flexibility is the reason that, the location and conformational states of the FFAs in the binding site of warfarin could not be determined accurately, despite numerous available X-ray structural studies. α-Linolenic acid competes favourably with warfarin at the binding site FA7. Isothermal titration calorimetry experiments of the preformed HSA/α-linolenic acid complex upon titration with warfarin show a significant reduction in the binding constant of warfarin, in very good agreement with NMR and computational data. The combined use, therefore, of STD, Tr-NOESY and INPHARMA NMR, ITC and docking calculations may find promising applications in the field of protein-lipid recognition research.

4.
Biosens Bioelectron ; 207: 114204, 2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35366578

RESUMO

Medical diagnostic sector is relying on affordable, handheld devices integrating smart biosensing and transducing interfaces that enable clinical analysis with minimal end-user intervention and resource requirements. In response, we propose here, a SIM card-type pH responsive polymer-modified paper-based biosensing device, coupled to a smartphone, for the determination of urinary creatinine. A vertical microfluidic channel was fabricated on a paper strip by wax printing. The hydrophilic area was coated by a poly(methylmethacrylate)/poly(methacrylic acid) random copolymer, PMMA-co-PMAA, and on top of it, creatinine deiminase (CD) was immobilized. Data demonstrated, on the one hand, zero vertical flow of urine through the enzyme-free PMMA-co-PMAA-modified paper strip, i.e., a high selectivity against the components of the matrix, and on the other hand, in the presence of CD, a creatinine -concentration dependent commence of sample's downward flow due to the selective, creatinine-triggered degradation of the copolymer by the enzymatically produced ammonia. This CD/PMMA-co-PMAA paper-based biosensing smart assembly is coupled with three conductive strips, which enable the automatic on/off (sample addition/measurement end) measurement of the copolymer degradation time, through electric resistance measurements. It also features an in-built sample well and wireless communication support through the integration of a Bluetooth® microprocessor incorporated with time and resistance measuring circuits. Using newly synthesized pH responsive PMMA-co-PMAA at different molecular weights and volume fraction ratios offering tunable dissolution properties, the detection range was adjusted over 3-30 mM creatinine to overspread the normal range of creatinine in urine. The device was successfully applied to the determination of urinary creatinine.


Assuntos
Técnicas Biossensoriais , Smartphone , Creatinina/urina , Polimetil Metacrilato/química , Urinálise
5.
J Biotechnol ; 350: 75-85, 2022 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-35430300

RESUMO

Process sustainability of biocatalytic processes is significantly empowered with the use of continuous-flow technologies that offer high productivity, minimal wastes and low volumetric consumption. Combining microreactor design with 3D printing technology can broaden the engineering potentials. This work proposes a protocol to modify the surface of 3D-printed PLA scaffolds, based on chitosan deposition. Mimicking the concept of microplates, multi-well plates were designed to facilitate parameter testing. Immobilization of laccase from Trametes versicolor was successfully performed, while chitosan and cross-linker concentration and incubation time were optimized. Τhe developed protocol was applied for the continuous flow bioconversion of hydroxyyrosol, yielding a TTN of 438.6 × 103 for a total of 10 h continuous use. Also, a peristaltic flow pattern seemed to favor the system performance, reaching 95% bioconversion efficiency in a total of 1 h reaction time. The potential of the developed system was further evaluated for the biotransformation of different biophenols from dietary sources, proving the efficiency of the system as a versatile biotechnological tool.


Assuntos
Quitosana , Trametes , Lacase/metabolismo , Poliésteres , Impressão Tridimensional
6.
Molecules ; 27(4)2022 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-35209022

RESUMO

Today, the use of natural biodegradable materials in the production processes is more and more adopted by industry to achieve cyclic economy targets and to improve environmental and human health indexes. Active packaging is the latest trend for food preservation. In this work, nanostructures were prepared by incorporation of thyme oil with natural natrium-montmorillonite and organo-montmorillonite with two different techniques, direct impregnation and the green evaporation-adsorption process. Such nanostructures were mixed with poly-L-lactic-acid for the first time via an extrusion molding process to develop a new packaging film. Comparisons of morphological, mechanical, and other basic properties for food packaging were carried out via XRD, FTIR, TG, SEM/EDS, oxygen and water vapor permeation, and antimicrobial and antioxidant activity for the first time. Results showed that poly-L-lactic-acid could be modified with clays and essential oils to produce improved active packaging films. The final product exhibits food odor prevention characteristics and shelf-life extension capabilities, and it could be used for active packaging. The films based on OrgMt clay seems to be more promising, while the thyme oil addition improves their behavior as active packaging. The PLLA/3%TO@OrgMt and PLLA/5%TO@OrgMt films were qualified between the tested samples as the most promising materials for this purpose.


Assuntos
Antioxidantes/química , Bentonita/química , Embalagem de Alimentos , Membranas Artificiais , Nanoestruturas/química , Óleos Vegetais/química , Poliésteres/química , Sódio/química , Timol/química , Thymus (Planta)/química , Anti-Infecciosos , Fenômenos Químicos , Fenômenos Mecânicos , Nanoestruturas/ultraestrutura , Análise Espectral
7.
Polymers (Basel) ; 13(23)2021 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-34883671

RESUMO

An approach to obtaining various nanostructures utilizing a well-studied polystyrene-b-poly(isoprene) or PS-b-PI diblock copolymer system through chemical modification reactions is reported. The complete hydrogenation and partial sulfonation to the susceptible carbon double bonds of the PI segment led to the preparation of [polystyrene-b-poly(ethylene-alt-propylene)] as well as [polystyrene-b-poly(sulfonated isoprene-co-isoprene)], respectively. The hydrogenation of the polyisoprene block results in enhanced segmental immiscibility, whereas the relative sulfonation induces an amphiphilic character in the final modified material. The successful synthesis of the pristine diblock copolymer through anionic polymerization and the relative chemical modification reactions were verified using several molecular and structural characterization techniques. The thin film structure-properties relationship was investigated using atomic force microscopy under various conditions such as different solvents and annealing temperatures. Small-angle X-ray scattering was employed to identify the different observed nanostructures and their evolution upon thermal annealing.

8.
Polymers (Basel) ; 13(21)2021 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-34771373

RESUMO

Novel hybrid materials of the PB-b-P(o-Bn-L-Tyr) and PI-b-P(o-Bn-L-Tyr) type (where PB: 1,4/1,2-poly(butadiene), PI: 3,4/1,2/1,4-poly(isoprene) and P(o-Bn-L-Tyr): poly(ortho-benzyl-L-tyrosine)) were synthesized through anionic and ring-opening polymerization under high-vacuum techniques. All final materials were molecularly characterized through infrared spectroscopy (IR) and proton and carbon nuclear magnetic resonance (1H-NMR, 13C-NMR) in order to confirm the successful synthesis and the polydiene microstructure content. The stereochemical behavior of secondary structures (α-helices and ß-sheets) of the polypeptide segments combined with the different polydiene microstructures was also studied. The influence of the α-helices and ß-sheets, as well as the polydiene chain conformations on the thermal properties (glass transition temperatures, thermal stability, α- and ß-relaxation) of the present biobased hybrid copolymers, was investigated through differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and dielectric spectroscopy (DS). The obtained morphologies in thin films for all the synthesized materials via atomic force microscopy (AFM) indicated the formation of polypeptide fibrils in the polydiene matrix.

9.
Polymers (Basel) ; 13(14)2021 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-34301065

RESUMO

A novel approach to obtaining nanocomposite materials using anionic sequential polymerization and post-synthetic esterification reactions with chemically modified graphene sheets (CMGs) is reported. The anionically synthesized diblock copolymer precursors of the PS-b-PI-OH type were grafted to the chemically modified -COOH groups of the CMGs, giving rise to the final composite materials, namely polystyrene-b-poly(isoprene)-g-CMGs, which exhibited enhanced physicochemical properties. The successful synthesis was determined through multiple molecular characterization techniques together with thermogravimetric analysis for the verification of increased thermal stability, and the structure/properties relationship was justified through transmission electron microscopy. Furthermore, the arrangement of CMGs utilizing lamellar and cylindrical morphologies was studied in order to determine the effect of the loaded CMGs in the adopted topologies.

10.
Molecules ; 26(6)2021 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-33805728

RESUMO

Hypergolic systems rely on organic fuel and a powerful oxidizer that spontaneously ignites upon contact without any external ignition source. Although their main utilization pertains to rocket fuels and propellants, it is only recently that hypergolics has been established from our group as a new general method for the synthesis of different morphologies of carbon nanostructures depending on the hypergolic pair (organic fuel-oxidizer). In search of new pairs, the hypergolic mixture described here contains polyaniline as the organic source of carbon and fuming nitric acid as strong oxidizer. Specifically, the two reagents react rapidly and spontaneously upon contact at ambient conditions to afford carbon nanosheets. Further liquid-phase exfoliation of the nanosheets in dimethylformamide results in dispersed single layers exhibiting strong Tyndall effect. The method can be extended to other conductive polymers, such as polythiophene and polypyrrole, leading to the formation of different type carbon nanostructures (e.g., photolumincent carbon dots). Apart from being a new synthesis pathway towards carbon nanomaterials and a new type of reaction for conductive polymers, the present hypergolic pairs also provide a novel set of rocket bipropellants based on conductive polymers.

11.
Polymers (Basel) ; 13(7)2021 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-33917281

RESUMO

A facile, single-step, [4+2] Diels-Alder cycloaddition reaction for the surface functionalization of single-walled carbon nanotubes (SWNTs) with end-capped polystyrene chains is presented. The thermal cycloaddition reaction took place at high temperature (~230 °C) without any catalyst between the sp2 network of carbon nanotubes, which acted as dienophile, and the diphenylethylene cyclobutene (DPE-CB) terminal group of the polystyrene chain. Anionic polymerization was employed for the synthesis of the polystyrene macromolecule, and successful and quantitative end-capping reaction with the DPE-CB molecule was confirmed by matrix-assisted laser desorption/ionization time of flight mass spectroscopy. Thermogravimetric analysis revealed the wt % of the grafted macromolecule on the CNT surface as well as the grafting density of the polymer chains on the SWNTs (0.027 chains nm-2). Direct evidence for the surface functionalization and the presence of thin polystyrene film was obtained by transmission electron microscopy (TEM) and by atomic force microscopy (AFM).

12.
Molecules ; 26(6)2021 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-33805641

RESUMO

An innovative process for the adsorption of the hydrophobic Basil-Oil (BO) into the hydrophilic food byproduct chitosan (CS) and the development of an advanced low-density polyethylene/chitosan/basil-oil (LDPE/CS_BO) active packaging film was investigated in this work. The idea of this study was the use of the BO as both a bioactive agent and a compatibilizer. The CS was modified to a CS_BO hydrophobic blend via a green evaporation/adsorption process. This blend was incorporated directly in the LDPE to produce films with advanced properties. All the obtained composite films exhibited improved packaging properties. The film with 10% CS_BO content exhibited the best packaging properties, i.e., 33.0% higher tensile stress, 31.0% higher water barrier, 54.3% higher oxygen barrier, and 12.3% higher antioxidant activity values compared to the corresponding values of the LDPE films. The lipid oxidation values of chicken breast fillets which were packaged under vacuum using this film were measured after seven and after fourteen days of storage. These values were found to be lower by around 41% and 45%, respectively, compared with the corresponding lipid oxidation values of pure LDPE film.


Assuntos
Galinhas , Quitosana , Embalagem de Alimentos/métodos , Óleos Vegetais , Polietileno , Animais , Antioxidantes/química , Plásticos Biodegradáveis/química , Varredura Diferencial de Calorimetria , Quitosana/química , Análise de Alimentos , Conservação de Alimentos/métodos , Tecnologia de Alimentos , Humanos , Interações Hidrofóbicas e Hidrofílicas , Peroxidação de Lipídeos , Microscopia Eletrônica de Varredura , Ocimum , Permeabilidade , Óleos Vegetais/química , Polietileno/química , Espectroscopia de Infravermelho com Transformada de Fourier , Resistência à Tração , Termogravimetria , Fatores de Tempo , Difração de Raios X
13.
Nanomaterials (Basel) ; 11(2)2021 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-33670153

RESUMO

In this work, hybrid zinc oxide-iron oxide (ZnOFe) magnetic nanoparticles were synthesized employing Olea europaea leaf aqueous extract as a reducing/chelating and capping medium. The resulting magnetic nanoparticles were characterized by basic spectroscopic and microscopic techniques, namely, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), fourier-transform infrared (FTIR) and atomic force microscopy (AFM), exhibiting a spherical shape, average size of 15-17 nm, and a functionalized surface. Lipase from Thermomyces lanuginosus (TLL) was efficiently immobilized on the surface of ZnOFe nanoparticles through physical absorption. The activity of immobilized lipase was found to directly depend on the enzyme to support the mass ratio, and also demonstrated improved pH and temperature activity range compared to free lipase. Furthermore, the novel magnetic nanobiocatalyst (ZnOFe-TLL) was applied to the preparation of hydroxytyrosyl fatty acid esters, including derivatives with omega-3 fatty acids, in non-aqueous media. Conversion yields up to 90% were observed in non-polar solvents, including hydrophobic ionic liquids. Different factors affecting the biocatalyst performance were studied. ZnOFe-TLL was reutilized for eight subsequent cycles, exhibiting 90% remaining esterification activity (720 h of total operation at 50 °C). The green synthesized magnetic nanoparticles, reported here for the first time, are excellent candidates as nanosupports for the immobilization of enzymes with industrial interest, giving rise to nanobiocatalysts with elevated features.

14.
Proc Natl Acad Sci U S A ; 118(11)2021 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-33688050

RESUMO

A series of cubic network phases was obtained from the self-assembly of a single-composition lamellae (L)-forming block copolymer (BCP) polystyrene-block-polydimethylsiloxane (PS-b-PDMS) through solution casting using a PS-selective solvent. An unusual network phase in diblock copolymers, double-primitive phase (DP) with space group of [Formula: see text], can be observed. With the reduction of solvent evaporation rate for solution casting, a double-diamond phase (DD) with space group of [Formula: see text] can be formed. By taking advantage of thermal annealing, order-order transitions from the DP and DD phases to a double-gyroid phase (DG) with space group of [Formula: see text] can be identified. The order-order transitions from DP (hexapod network) to DD (tetrapod network), and finally to DG (trigonal planar network) are attributed to the reduction of the degree of packing frustration within the junction (node), different from the predicted Bonnet transformation from DD to DG, and finally to DP based on enthalpic consideration only. This discovery suggests a new methodology to acquire various network phases from a simple diblock system by kinetically controlling self-assembling process.

15.
Molecules ; 25(24)2020 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-33352785

RESUMO

To the best of our knowledge, this is the very first time that a thorough study of the synthetic procedures, molecular and thermal characterization, followed by structure/properties relationship for symmetric and non-symmetric second generation (2-G) dendritic terpolymers is reported. Actually, the synthesis of the non-symmetric materials is reported for the first time in the literature. Anionic polymerization enables the synthesis of well-defined polymers that, despite the architecture complexity, absolute control over the average molecular weight, as well as block composition, is achieved. The dendritic type macromolecular architecture affects the microphase separation, because different morphologies are obtained, which do not exhibit long range order, and various defects or dislocations are evident attributed to the increased number of junction points of the final material despite the satisfactory thermal annealing at temperatures above the highest glass transition temperature of all blocks. For comparison reasons, the initial dendrons (miktoarm star terpolymer precursors) which are connected to each other in order to synthesize the final dendritic terpolymers are characterized in solution and in bulk and their self-assembly is also studied. A major conclusion is that specific structures are adopted which depend on the type of the core connection between the ligand and the active sites of the dendrons.


Assuntos
Dendrímeros/química , Polímeros/química , Polimerização , Temperatura
16.
Nanomaterials (Basel) ; 11(1)2020 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-33374901

RESUMO

In hypergolics two substances ignite spontaneously upon contact without external aid. Although the concept mostly applies to rocket fuels and propellants, it is only recently that hypergolics has been recognized from our group as a radically new methodology towards carbon materials synthesis. Comparatively to other preparative methods, hypergolics allows the rapid and spontaneous formation of carbon at ambient conditions in an exothermic manner (e.g., the method releases both carbon and energy at room temperature and atmospheric pressure). In an effort to further build upon the idea of hypergolic synthesis, herein we exploit a classic liquid rocket bipropellant composed of furfuryl alcohol and fuming nitric acid to prepare carbon nanosheets by simply mixing the two reagents at ambient conditions. Furfuryl alcohol served as the carbon source while fuming nitric acid as a strong oxidizer. On ignition the temperature is raised high enough to induce carbonization in a sort of in-situ pyrolytic process. Simultaneously, the released energy was directly converted into useful work, such as heating a liquid to boiling or placing Crookes radiometer into motion. Apart from its value as a new synthesis approach in materials science, carbon from rocket fuel additionally provides a practical way in processing rocket fuel waste or disposed rocket fuels.

17.
Molecules ; 25(23)2020 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-33255708

RESUMO

The synthesis of two (2) novel triblock terpolymers of the ABC type and one (1) of the BAC type, where A, B and C are chemically different segments, such as polystyrene (PS), poly(butadiene) (PB1,4) and poly(dimethylsiloxane) (PDMS), is reported; moreover, their corresponding molecular and bulk characterizations were performed. Very low dimensions are evident from the characterization in bulk from transmission electron microscopy studies, verified by small-angle X-ray data, since sub-16 nm domains are evident in all three cases. The self-assembly results justify the assumptions that the high Flory-Huggins parameter, χ, even in low molecular weights, leads to significantly well-ordered structures, despite the complexity of the systems studied. Furthermore, it is the first time that a structure/properties relationship was studied for such systems in bulk, potentially leading to prominent applications in nanotechnology and nanopatterning, for as low as sub-10 nm thin-film manipulations.


Assuntos
Peso Molecular , Polimerização , Polímeros/química , Ânions/química , Microscopia Eletrônica de Transmissão , Análise Espectral , Temperatura
18.
Pharmaceuticals (Basel) ; 13(11)2020 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-33238426

RESUMO

Secretory phospholipase-IIA A2 (sPLA2-IIA) is expressed in a variety of cell types under inflammatory conditions. Its presence in the bronchoalveolar lavage (BAL) fluid of patients with acute respiratory distress syndrome (ARDS) is associated with the severity of the injury. Exosomal type extracellular vesicles, (EVs), are recognized to perform intercellular communication. They may alter the immune status of recipient target cells through cargo shuttling. In this work, we characterized the exosomal type EVs isolated from BAL fluid of patients with early and late ARDS as compared to control/non-ARDS patients, through morphological (confocal and electron microscopy) and biochemical (dynamic light scattering, qRT-PCR, immunoblotting) approaches. We provide evidence for the presence of an sPLA2-IIA-carrying EV pool that coprecipitates with exosomes in the BAL fluid of patients with ARDS. PLA2G2A mRNA was present in all the samples, although more prominently expressed in early ARDS. However, the protein was found only in EVs from early phase ARDS. Under both forms, sPLA2-IIA might be involved in inflammatory responses of recipient lung cells during ARDS. The perception of the association of sPLA2-IIA to the early diagnosis of ARDS or even with a mechanism of development and propagation of lung inflammation can help in the adoption of appropriate and innovative therapeutic strategies.

19.
Nanomaterials (Basel) ; 10(8)2020 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-32751589

RESUMO

The synthesis, molecular and morphological characterization of a 3-miktoarm star terpolymer of polystyrene (PS, M¯n = 61.0 kg/mol), polybutadiene (PB, M¯n = 38.2 kg/mol) and polyisoprene (PI, M¯n = 29.2 kg/mol), corresponding to volume fractions (φ) of 0.46, 0.31 and 0.23 respectively, was studied. The major difference of the present material from previous ABC miktoarm stars (which is a star architecture bearing three different segments, all connected to a single junction point) with the same block components is the high 3,4-microstructure (55%) of the PI chains. The interaction parameter and the degree of polymerization of the two polydienes is sufficiently positive to create a three-phase microdomain structure as evidenced by differential scanning calorimetry and transmission electron microscopy (TEM). These results in combination with small-angle X-ray scattering (SAXS) and birefringence experiments suggest a cubic tricontinuous network structure, based on the I4132 space group never reported previously for such an architecture.

20.
Molecules ; 25(9)2020 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-32397274

RESUMO

Recently we have highlighted the importance of hypergolic reactions in carbon materials synthesis. In an effort to expand this topic with additional new paradigms, herein we present novel preparations of carbon nanomaterials, such-like carbon nanosheets and fullerols (hydroxylated fullerenes), through spontaneous ignition of coffee-sodium peroxide (Na2O2) and C60-Na2O2 hypergolic mixtures, respectively. In these cases, coffee and fullerenes played the role of the combustible fuel, whereas sodium peroxide the role of the strong oxidizer (e.g., source of highly concentrated H2O2). The involved reactions are both thermodynamically and kinetically favoured, thus allowing rapid product formation at ambient conditions. In addition, we provide tips on how to exploit the released energy of such highly exothermic reactions in the generation of useful work.


Assuntos
Fulerenos/química , Oxirredução , Peróxidos/química
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