All starch fractions not digested and absorbed in the small intestine of healthy humans are considered resistant starch (RS), and their habitual intake has been associated with different beneficial ...effects on health. In particular, starch-lipid V-type complexes, such as starch-fatty acids and starch-monoglycerides, have traditionally been classified as type 5 RS.
Other starch V-type complexes have emerged more recently, such as starch-glycerol, starch-amino acids, starch-peptides, starch-proteins, starch-lipid-protein, starch-polyphenols, starch-other polysaccharides, among others, which do not fit well into the traditionally accepted nutritional classification of RS. Here, these complexes are analyzed in order to highlight the pertinence of redefining RS5 for the inclusion of this new type of RS.
All those self-assembled starch V-type complexes can be classified as RS5. However, starch-polyphenol V-type complexes should particularly be further investigated to ensure their inclusion in this new extended RS5.
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•The update of the resistant starch type 5 (RS5) concept was exhaustively discussed.•All self-assembled starch V-type complexes can be considered RS5.•Self-assembled starch V-type complexes may find industrial uses as functional food additives.
Self-assembly of quasi-spherical colloidal particles in two-dimensional (2D) arrangements is essential for a wide range of applications from optoelectronics to surface engineering, from chemical and ...biological sensing to light harvesting and environmental remediation. Several self-assembly approaches have flourished throughout the years, with specific features in terms of complexity of the implementation, sensitivity to process parameters, characteristics of the final colloidal assembly. Selecting the proper method for a given application amidst the vast literature in this field can be a challenging task. In this review, we present an extensive classification and comparison of the different techniques adopted for 2D self-assembly in order to provide useful guidelines for scientists approaching this field. After an overview of the main applications of 2D colloidal assemblies, we describe the main mechanisms underlying their formation and introduce the mathematical tools commonly used to analyse their final morphology. Subsequently, we examine in detail each class of self-assembly techniques, with an explanation of the physical processes intervening in crystallization and a thorough investigation of the technical peculiarities of the different practical implementations. We point out the specific characteristics of the set-ups and apparatuses developed for self-assembly in terms of complexity, requirements, reproducibility, robustness, sensitivity to process parameters and morphology of the final colloidal pattern. Such an analysis will help the reader to individuate more easily the approach more suitable for a given application and will draw the attention towards the importance of the details of each implementation for the final results.
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•A thorough compendium of two-dimensional colloidal self-assembly is presented.•Self-assembly applications and mechanisms behind crystallization are introduced.•The theoretical tools for the analysis of colloidal structures are illustrated.•The different approaches for self-assembly are classified and described in detail.•The advances in the implementations of colloidal assembly are pointed out.
Depletion‐induced self‐assembly is routinely used to separate plasmonic nanoparticles (NPs) of different shapes, but less often for its ability to create supercrystals (SCs) in suspension. Therefore, ...these plasmonic assemblies have not yet reached a high level of maturity and their in‐depth characterization by a combination of in situ techniques is still very much needed. In this work, gold triangles (AuNTs) and silver nanorods (AgNRs) are assembled by depletion‐induced self‐assembly. Small Angle X‐ray Scattering (SAXS) and scanning electron microscopy (SEM) analysis shows that the AuNTs and AgNRs form 3D and 2D hexagonal lattices in bulk, respectively. The colloidal crystals are also imaged by in situ Liquid‐Cell Transmission Electron Microscopy. Under confinement, the affinity of the NPs for the liquid cell windows reduces their ability to stack perpendicularly to the membrane and lead to SCs with a lower dimensionality than their bulk counterparts. Moreover, extended beam irradiation leads to disassembly of the lattices, which is well described by a model accounting for the desorption kinetics highlighting the key role of the NP‐membrane interaction in the structural properties of SCs in the liquid‐cell. The results shed light on the reconfigurability of NP superlattices obtained by depletion‐induced self‐assembly, which can rearrange under confinement.
Gold triangles (AuNTs) and silver nanorods (AgNRs) are assembled by depletion‐induced self‐assembly. Structural analysis shows that the AuNTs and AgNRs form 3D and 2D hexagonal lattices in bulk, respectively. The colloidal crystals are also imaged by in situ Liquid‐Cell Transmission Electron Microscopy. Under confinement, the affinity of the nanoparticles for the liquid cell windows leads to SCs with a lower dimensionality than their bulk counterparts.
Promoted by the demand for wearable devices, graphene has been proved to be a promising material for potential applications in flexible and highly sensitive strain sensors. However, low sensitivity ...and complex processing of graphene retard the development toward the practical applications. Here, an environment‐friendly and cost‐effective method to fabricate large‐area ultrathin graphene films is proposed for highly sensitive flexible strain sensor. The assembled graphene films are derived rapidly at the liquid/air interface by Marangoni effect and the area can be scaled up. These graphene‐based strain sensors exhibit extremely high sensitivity with gauge factor of 1037 at 2% strain, which represents the highest value for graphene platelets at this small deformation so far. This simple fabrication for strain sensors with highly sensitive performance of strain sensor makes it a novel approach to applications in electronic skin, wearable sensors, and health monitoring platforms.
An environment‐friendly and cost‐effective method to fabricate large‐area ultrathin graphene films is proposed for highly sensitive flexible strain sensing applications. This simple Marangoni‐effect‐based fabrication makes it a novel approach to applications in electronic skin, wearable sensors, and health monitoring platforms.
All in order: The self‐assembly of nanocrystalline cellulose (NCC) with hydrogel precursors leads to nanocomposites with long‐range chiral nematic order. The combination of chiral structure and ...hydrogel swelling behavior gives rise to iridescence that rapidly responds to various stimuli.
•Metal oxide (MOx)-decorated graphene-based sensor array was presented.•Sensing properties of MOx/graphene composite toward ammonia and formaldehyde were investigated.•Neural network-based model was ...used for the detection of formaldehyde and ammonia mixture.
This paper reports metal oxide (MOx)-decorated graphene-based sensor array combining with back-propagation (BP) neural network toward the detection of indoor air pollutant exposure. Tin dioxide (SnO2) nanospheres and copper oxide (CuO) nanoflowers-decorated graphene were used as candidates for formaldehyde and ammonia gas sensing, respectively. The as-synthesized sensing materials were characterized in terms of their nanostructural, morphological and compositional features by SEM, Raman spectra, and XRD. The sensor array was fabricated via one-step hydrothermal route and layer-by-layer (LbL) self-assembly technique on the substrate with interdigital microelectrodes. The sensing properties of MOx/graphene composite toward the mixture gas of ammonia and formaldehyde, such as dynamic response, sensitivity, response/recovery time, and stability, were investigated at room temperature. And furthermore, this work successfully achieved the recognition and quantitative prediction of components in the gas mixture of formaldehyde and ammonia through the combination of MOx/graphene-based sensor array and neural network-based signal processing technologies.
A facile approach for the fabrication of novel black plasmonic colloidosomes assembled from Au nanospheres is developed by an emulsion‐templating strategy. This self‐assembly process is based on a ...new reverse water‐in‐1‐butanol emulsion system, in which the water emulsion droplets can dissolve into 1‐butanol (oil) phase at an appropriate rate. These Au colloidosomes possess hexagonal close‐packed multilayer shells and show a low reflectivity and intense broadband absorption owing to the strong interparticle plasmonic coupling, which is further investigated by a finite‐difference time‐domain method. This method is universal and is suitable for self‐assembly of different noble‐metal nanoparticles into different colloidosomes. These colloidosomes have important applications in photothermal therapy, biosensors, and drug delivery.
Black colloidosomes: 3D hollow plasmonic colloidosomes (see picture) composed of hexagonal close‐packed gold nanospheres were self‐assembled by a new reverse water‐in‐1‐butanol emulsion system. These gold colloidosomes display a strong plasmonic coupling effect with broadband light absorption, show black color intrinsically, and are therefore denoted as black gold.
Lead halide perovskite nanocrystals (NCs) with bright luminescence and broad spectral tunability are good candidates as smart probes for bioimaging, but suffer from hydrolysis even when exposed to ...atmosphere moisture. In this paper, a strategy is demonstrated by embedding CsPbX3 (X = Cl, Br, I) NCs into microhemispheres (MHSs) of polystyrene matrix to prepare “water‐resistant” NCs@MHSs hybrids as multicolor multiplexed optical coding agents. First, a facile room‐temperature solution self‐assembly approach to highly luminescent colloidal CsPbX3 NCs is developed by injecting a stock solution of CsX⋅PbX2 in N,N‐dimethylformamide into dichloromethane. Polyvinyl pyrrolidone (PVP) is chosen as the capping ligand, which is physically adsorbed and wrapped on the surface of perovskite NCs to form a protective layer. The PVP protective layer not only leads to composition‐tunable CsPbX3 NCs with high quantum yields and narrow emission linewidths of 12–34 nm but also acts as an interfacial layer, making perovskite NCs compatible with polystyrene polymers and facilitating the next step to embed CsPbX3 NCs into polymer MHSs. CsPbX3 NCs@MHSs are demonstrated as multicolor luminescence probes in live cells with high stability and nontoxicity. Using ten intensity levels and seven‐color NCs@MHSs that show non‐overlapping spectra, it will be possible to individually tag about ten million cells.
A strategy to overcome the inherent vulnerability of perovskites to water is demonstrated by embedding CsPbX3 nanocrystals (NCs) into microhemispheres (MHSs) of polystyrene matrix to prepare “water‐resistant” NCs@MHSs hybrids. NCs@MHSs are demonstrated as multicolor luminescence probes in live cells with high stability and nontoxicity. Using ten intensity levels and seven‐color NCs@MHSs, it will be possible to individually tag about ten million cells.
Single‐crystalline square microdisks of CH3NH3PbBr3 are prepared by using a one‐step solution self‐assembly method. Single‐mode lasing at 557 nm is achieved based on a built‐in whispering gallery ...mode microresonator at room temperature. By partial replacement of Br with Cl, lasing wavelengths are continuously tuned from 525 to 557 nm.
Synaptic devices with linear high‐speed switching can accelerate learning in artificial neural networks (ANNs) embodied in hardware. Conventional resistive memories however suffer from high write ...noise and asymmetric conductance tuning, preventing parallel programming of ANN arrays. Electrochemical random‐access memories (ECRAMs), where resistive switching occurs by ion insertion into a redox‐active channel, aim to address these challenges due to their linear switching and low noise. ECRAMs using 2D materials and metal oxides however suffer from slow ion kinetics, whereas organic ECRAMs enable high‐speed operation but face challenges toward on‐chip integration due to poor temperature stability of polymers. Here, ECRAMs using 2D titanium carbide (Ti3C2Tx) MXene that combine the high speed of organics and the integration compatibility of inorganic materials in a single high‐performance device are demonstrated. These ECRAMs combine the speed, linearity, write noise, switching energy, and endurance metrics essential for parallel acceleration of ANNs, and importantly, they are stable after heat treatment needed for back‐end‐of‐line integration with Si electronics. The high speed and performance of these ECRAMs introduces MXenes, a large family of 2D carbides and nitrides with more than 30 stoichiometric compositions synthesized to date, as promising candidates for devices operating at the nexus of electrochemistry and electronics.
Electrochemical random‐access memories using multilayered 2D titanium carbide MXene that combine the speed, linearity, write noise, switching energy, and endurance metrics essential for parallel acceleration of artificial neural networks with near ideal numerical accuracy in image recognition simulations are reported. The multilayered 2D MXene films are also stable after heat treatment needed for back‐end‐of‐line integration with Si electronics.
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