Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 6 de 6
Filtrar
Mais filtros










Base de dados
Assunto principal
Intervalo de ano de publicação
1.
Sci Total Environ ; 868: 161547, 2023 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-36642279

RESUMO

Carbon dioxide (CO2) is the most important greenhouse gas (GHG), accounting for 76% of all GHG emissions. The atmospheric CO2 concentration has increased from 280 ppm in the pre-industrial era to about 418 ppm, and is projected to reach 570 ppm by the end of the 21st century. In addition to reducing CO2 emissions from anthropogenic activities, strategies to adequately address climate change must include CO2 capture. To promote circular economy, captured CO2 should be converted to value-added materials such as fuels and other chemical feedstock. Due to their tunable chemistry (which allows them to be selective) and high surface area (which allows them to be efficient), engineered nanomaterials are promising for CO2 capturing and/or transformation. This work critically reviewed the application of nanomaterials for the transformation of CO2 into various fuels, like formic acid, carbon monoxide, methanol, and ethanol. We discussed the literature on the use of metal-based nanomaterials, inorganic/organic nanocomposites, as well as other routes suitable for CO2 conversion such as the electrochemical, non-thermal plasma, and hydrogenation routes. The characteristics, steps, mechanisms, and challenges associated with the different transformation technologies were also discussed. Finally, we presented a section on the outlook of the field, which includes recommendations for how to continue to advance the use of nanotechnology for conversion of CO2 to fuels.

2.
IUCrdata ; 7(Pt 8): x220771, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36340974

RESUMO

The title AgI complex, [Ag(NO2)(C19H17P)2], reveals a distorted pseudo-trigonal-planar shape around the AgI atom geometry resulting from the coordination of two phosphine ligands, as well as a nitrito-O,O' ligand coordinating to the silver(I) atom through the oxygen atoms; in this description, the two oxygen atoms are assumed to occupy one position, forming an acute O-Ag-O angle of 51.44 (9)°. The plane resulting from the NO2 coordination to Ag is nearly perpendicular to the plane from the coordination of the phosphine-P atoms to Ag [dihedral angle = 86.43 (9)°].

3.
Sci Rep ; 12(1): 12347, 2022 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-35853931

RESUMO

Presentation of foods is essential to promote the acceptance of diversified and novel products. This study examined the color profile, browning index (BI), and structural properties of 3D-printed and traditional biscuits from whole-grain (WG) sourdough and germinated flours. The processed flours and composite/multigrain flours comprising cowpea sourdough (CS) and quinoa malt (QM) were used to prepare the snacks, and their structural characteristics were determined. Compared with the traditional biscuits, the 3D-printed biscuits showed considerable distinction in terms of consistent structural design and color intensities. The in-barrel shearing effect on dough biopolymers, automated printing of replicated dough strands in layers, and expansion during baking might have caused the biscuits' structural differences. The composite biscuit formulations had a proportional share of CS and QM characteristics. The 80% CS and 20% QM printed biscuit had a low redness and BI, increased cell volume, average cell area, and total concavity. The 60% CS and 40% QM printed snack showed improved lightness and yellowness, increased average cell elongation, and less hardness. The 3D-printed composite biscuits may be recommended based on their unique structural characteristics. Such attributes can enhance the acceptability of printed foods and reinvent locally prepared meals as trendy, sustainable, and functional foods.


Assuntos
Farinha , Vigna , Farinha/análise , Impressão Tridimensional , Lanches , Vigna/química , Grãos Integrais
4.
RSC Adv ; 12(31): 19890-19900, 2022 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-35865205

RESUMO

The use of water as a solvent in chemical reactions has recently been brought to public attention, especially in the exploration of eco-friendly procedures. It is readily available, abundantly accessible, non-toxic, non-flammable, and at a low cost. As opposed to the previous limitation of reactant solubilities associated with aqueous media, a hydrogel such as a hydroxypropyl methylcellulose (HPMC) solution can significantly improve the reactant solubility. This investigation employed water and HPMC as the reaction solvent, and the reaction medium viscosity was impressively enhanced. Silica-supported Pd particles (Pd@SiO2) were synthesized and effectively catalyzed the reduction of acetophenone in the presence of sodium borohydride (NaBH4) as the hydrogen source. The conversion of acetophenone to 1-phenyl ethanol remained at a very high value of >99.34% with 100% selectivity towards 1-phenyl ethanol.

5.
IUCrdata ; 7(Pt 12): x221147, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36628192

RESUMO

The mol-ecular structure of the title complex, [Ag(NO3)(C19H17P)3], exhibits a severely distorted tetra-hedral coordination environment around the central AgI atom, comprising one O and three P atoms. Apart from a primary Ag-O coordination of the nitrato ligand of 2.667 (3) Å, a second (weaker) secondary inter-action of the nitrato ligand via the other O atom of 3.118 (4) Šis observed. The compound crystallizes with a complete mol-ecule in the asymmetric unit. Weak C-H⋯O inter-actions consolidate the packing.

6.
J Mater Sci ; 56(30): 16824-16850, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34413542

RESUMO

Three-dimensional (3-D) printing, also known as additive manufacturing, refers to a method used to generate a physical object by joining materials in a layer-by-layer process from a three-dimensional virtual model. 3-D printing technology has been traditionally employed in rapid prototyping, engineering, and industrial design. More recently, new applications continue to emerge; this is because of its exceptional advantage and flexibility over the traditional manufacturing process. Unlike other conventional manufacturing methods, which are fundamentally subtractive, 3-D printing is additive and, therefore, produces less waste. This review comprehensively summarises the application of additive manufacturing technologies in chemistry, chemical synthesis, and catalysis with particular attention to the production of general laboratory hardware, analytical facilities, reaction devices, and catalytically active substances. It also focuses on new and upcoming applications such as digital chemical synthesis, automation, and robotics in a synthetic environment. While discussing the contribution of this research area in the last decade, the current, future, and economic opportunities of additive manufacturing in chemical research and material development were fully covered.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...