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This paper provides an overview of recent progress made in the area of cellulose nanofibre-based nanocomposites. An introduction into the methods used to isolate cellulose nanofibres (nanowhiskers, nanofibrils) is given, with details of their structure. Following this, the article is split into sections dealing with processing and characterisation of cellulose nanocomposites and new developments in the area, with particular emphasis on applications. The types of cellulose nanofibres covered are those extracted from plants by acid hydrolysis (nanowhiskers), mechanical treatment and those that occur naturally (tunicate nanowhiskers) or under culturing conditions (bacterial cellulose nanofibrils). Research highlighted in the article are the use of cellulose nanowhiskers for shape memory nanocomposites, analysis of the interfacial properties of cellulose nanowhisker and nanofibril-based composites using Raman spectroscopy, switchable interfaces that mimic sea cucumbers, polymerisation from the surface of cellulose nanowhiskers by atom transfer radical polymerisation and ring opening polymerisation, and methods to analyse the dispersion of nanowhiskers. The applications and new advances covered in this review are the use of cellulose nanofibres to reinforce adhesives, to make optically transparent paper for electronic displays, to create DNA-hybrid materials, to generate hierarchical composites and for use in foams, aerogels and starch nanocomposites and the use of all-cellulose nanocomposites for enhanced coupling between matrix and fibre. A comprehensive coverage of the literature is given and some suggestions on where the field is likely to advance in the future are discussed.

All-cellulose composite (ACC) films from oil palm empty fruit bunches (OPEFBs) were successfully fabricated through the surface selective dissolution of cellulose fibers in 8 wt% LiCl/DMAc via the solution casting method. The effect of dissolution time on the properties of the ACC films was assessed in the range of 5–45 min. The results showed that under the best conditions, there were sufficiently dissolved fiber surfaces that improved the interfacial adhesion while maintaining a sizable fraction of the fiber cores, acting as reinforcements for the material. The ACC films have the highest tensile strength and modulus of elasticity of up to 35.78 MPa and 2.63 GPa after 15 min of dissolution. Meanwhile, an X-ray diffraction analysis proved that cellulose I and II coexisted, which suggests that the crystallite size and degree of crystallinity of the ACC films had significantly declined. This is due to a change in the cellulose structure, which results in fewer voids and enhanced stress distribution in the matrix. Scanning electron microscopy revealed that the interfacial adhesion improved between the reinforcing fibers and matrices as the failure behavior of the film composite changed from fiber pullout to fiber breakage and matrix cracking. On the other hand, the thermal stability of the ACC film showed a declining trend as the dissolution time increased. Therefore, the best dissolution time to formulate the ACC film was 15 min, and the obtained ACC film is a promising material to replace synthetic polymers as a green composite.

The presence of defects like gas bubble in fabricated parts is inherent in the selective laser sintering process and the prediction of bubble shrinkage dynamics is crucial. In this paper, two artificial intelligence (AI) models based on Decision Trees algorithm were constructed in order to predict bubble dissolution time, namely the Ensemble Bagged Trees (EDT Bagged) and Ensemble Boosted Trees (EDT Boosted). A metadata including 68644 data were generated with the help of our previously developed numerical tool. The AI models used the initial bubble size, external domain size, diffusion coefficient, surface tension, viscosity, initial concentration, and chamber pressure as input parameters, whereas bubble dissolution time was considered as output variable. Evaluation of the models’ performance was achieved by criteria such as Mean Absolute Error (MAE), Root Mean Squared Error (RMSE) and coefficient of determination (R2). The results showed that EDT Bagged outperformed EDT Boosted. Sensitivity analysis was then conducted thanks to the Monte Carlo approach and it was found that three most important inputs for the problem were the diffusion coefficient, initial concentration, and bubble initial size. This study might help in quick prediction of bubble dissolution time to improve the production quality from industry.

This study determined the critical parameters for the morphological development of the electrode surface (the critical potential and the critical charge) during anodic selective dissolution of a Cu–Pd alloy with a volume concentration of 15 at.% palladium. When the critical values were exceeded, a phase transition occurred with the formation of palladium’s own phase. Chronoamperometry aided in the determination of the partial rates of copper ionization and phase transformation of palladium under overcritical selective dissolution conditions. The study determined that the formation of a new palladium phase is controlled by a surface diffusion of the ad-atom to the growing three-dimensional nucleus under instantaneous activation of the nucleation centres. We also identified the role of this process in the formation of the electrocatalytic activity of the anodically modified alloy during electro-oxidation of formic acid. This study demonstrated that HCOOH is only oxidated at a relatively high rate on the surface of the Cu85Pd15 alloy, which is subjected to selective dissolution under overcritical conditions. This can be explained by the fact that during selective dissolution of the alloy, a pure palladium phase is formed on its highly developed surface which has prominent catalytic activity towards the electro-oxidation of formic acid. The rate of electro-oxidation of HCOOH on the surface of the anodically modified alloy increased with the growth of the potential and the charge of selective dissolution, which can be used to obtain an electrode palladium electrocatalyst with a set level of electrocatalytic activity towards the anodic oxidation of formic acid.

Silver(I) oxide was anodically formed in a deaerated 0.1 M KOH aqueous solution on Ag and Ag–Zn alloys (from 5 to 30 at.% of zinc) subjected to anodic selective dissolution in a deaerated 0.01 M HNO 3  + 0.09 М KNO 3 aqueous solution. Under these conditions, a layer is formed on the surface of the alloy enriched with silver and structural defects whose concentration is significantly higher than the equilibrium one. Scanning electron microscopy, impedancemetry, and photopotential measurements were used. It was determined that irrespective of the concentration of the non-equilibrium defects in the surface layer of the alloy, the n -type silver(I) oxide was formed with prevailing donor defects, spheroid morphology, and a relatively low chemical stability in an aqueous alkaline solution. The higher the concentration of zinc in the alloy and structural defects in its surface layer, the lower the diameter of silver(I) oxide crystallites. An increase in the flat band potential of silver(I) oxide from 0.428 to 0.454 V following an increase in the concentration of superequilibrium defects in the alloy’s surface layer from 17.1⋅10 −4 to 65.3⋅10 −4 at.% is only observed for the alloy with the concentration of zinc of 5 at.%. The concentration of donor defects in the silver(I) oxide generally increases following an increase in the concentration of zinc in the alloy. The dependence of concentration of donor defects in the silver(I) oxide on the concentration of superequilibrium defects in the alloys surface layer is non-monotonic. The rate constant of chemical dissolution of the silver(I) oxide decreases following both an increase in the concentration of zinc in the alloy and an increase in the concentration of defects in its surface layer.

Porous carbon (PC) is a promising electromagnetic (EM) wave absorbing material thanks to its light weight, large specific surface area as well as good dissipating capacity. To further improve its microwave absorbing performance, silver coated porous carbon (Ag@PC) is synthesized by one-step hydro-thermal synthesis process making use of fir as a biomass formwork. Phase compositions, morphological structure, and microwave absorption capability of the Ag@PC has been explored. Research results show that the metallic Ag was successfully reduced and the particles are evenly distributed inward the pores of the carbon formwork, which accelerates graphitization process of the amorphous carbon. The Ag@PC composite without adding polyvinyl pyrrolidone (PVP) exhibits higher dielectric constant and better EM wave dissipating capability. This is because the larger particles of Ag give rise to higher electric conductivity. After combing with frequency selective surface (FSS), the EM wave absorbing performance is further improved and the frequency region below −10 dB is located in 8.20–11.75 GHz, and the minimal reflection loss value is −22.5 dB. This work indicates that incorporating metallic Ag particles and FSS provides a valid way to strengthen EM wave absorbing capacity of PC material.

In this study, polyacrylonitrile (PAN) was mixed with a renewable polymer, lignin, to produce electrospun nanofibers by using an electrospinning technique. Lignin was utilized as a soft template that was removed from the nanofibers by using a selective dissolution technique to create porous PAN nanofibers. These nanofibers were characterized with Fourier transform infrared (FTIR), field emission scanning electron microscopy (FESEM), thermogravimetry analysis (TGA), X-ray diffraction (XRD), and Brunauer-Emmett-Teller (BET) to study their properties and morphology. The results showed that lignin can be homogeneously mixed into the PAN solution and successfully electrospun into nanofibers. FESEM results showed a strong relationship between the PAN: lignin ratio and the diameter of the electrospun fibers. Lignin was successfully removed from electrospun nanofibers by a selective chemical dissolution technique, which resulted in roughness and porousness on the surface of the nanofibers. Based on the BET result, the specific surface area of the PAN/lignin nanofibers was more than doubled following the removal of lignin compared to PAN nanofibers. The highest specific surface area of nanofibers after selective chemical dissolution was found at an 8:2 ratio of PAN/lignin, which was 32.42 m2g−1 with an average pore diameter of 5.02 nm. The diameter of electrospun nanofibers was also slightly reduced after selective chemical dissolution. Porous PAN nanofibers can be seen as the precursors to the production of highly porous carbon nanofibers.

Dissolutions of the fluorite (111) crystallographic plane and fluorite (CaF2) colloidal particles were studied as a function of pH. The process was examined by measuring the concentration of released fluoride and calcium ions by ion-selective electrodes. Additionally, electrokinetic and inner surface potentials were measured by means of electrophoresis and a fluorite single crystal electrode respectively. The rate of fluorite dissolution was analysed assuming a reaction mechanism with a series of elementary steps, which included the reaction of surface groups with H+ ions, the formation of F? vacancies, the dissociation of surface groups and the release of calcium and fluoride ions into the interfacial region as well as the diffusion of ions from the interfacial region. The proposed reaction mechanism indicates that H+ ions play a necessary role in allowing the dissolution to take place, a concept not possible to confirm by looking at the overall equation of fluorite dissolution. The order of the total reaction with respect to H+ ions was found to be 0.37, which is in good accordance with the value derived from the reaction mechanism (1/3). The experimentally determined rate coefficient of fluorite dissolution was found to be kdis?=?9?×?10?6?mol2/3?dm?m?2?s?1.

Rare earth elements (REEs) are critical for advanced technologies, with neodymium and praseodymium being essential to high-performance permanent magnets. The separation of these adjacent lanthanides represents a significant challenge due to their nearly identical chemical properties, with traditional chitosan surfaces exhibiting limited discrimination between chemically similar elements. Current separation methods require multiple processing steps and cannot maintain predetermined compositional ratios. Engineered polymer interfaces with controlled binding site distribution represents a critical advancement for selective separation, but achieving ratio-controlled extraction of adjacent elements remains challenging. Here, we demonstrate a novel interface engineering approach using alkali/urea dissolution to restructure chitosan networks, creating dual-template alkali/urea chitosan hydrogels (NdPr-AUCH) for simultaneous selective co-extraction of Nd(III) and Pr(III). We show that the dissolution–reformation process enables templated Nd:Pr selectivity ratios (1:1, 2:1, and 4:1) that directly correspond to synthesis compositions. NdPr-AUCH-11 achieved maximum uptake capacities of 19.85 mg/g for Nd(III) and 16.89 mg/g for Pr(III), while NdPr-AUCH-41 maintained 3.07:1 Nd:Pr selectivity in competitive environments. Thermodynamic analyses reveal consistently lower energy requirements for Nd(III) binding compared to Pr(III), demonstrating how interface engineering amplifies coordination differences between adjacent lanthanides. This work represents the first demonstration of ratio-controlled extraction of adjacent lanthanides within a single polymer matrix, advancing interface-engineered materials for selective rare earth recovery.

The present paper describes the influence of both flexure quasi-static and fatigue loading on polyamide 12 (PA12) specimens fabricated by fused filament fabrication (FFF) and selective laser sintering (SLS) processes. Rectangular prisms (ISO 178:2010) of polymer were printed and tested under sinusoidal three-point bending fatigue loading at a frequency of 5 Hz. The differences in porosity, surface roughness, and degree of crystallinity are systematically measured and linked to the mechanical fatigue properties. Fatigue analysis in the visco-elastic domain of the polymer is fully described, from fatigue behavior to energy analysis. Here, we have shown that the fatigue properties of the FFF specimens are found to be higher than those of the SLS specimens, despite their lower degree of crystallinity (more than four times). The presence of pores and their growth during fatigue tests in the sintered PA12 specimen seem to be responsible. The fatigue loss factor analysis shows that at lower stress levels, PA12 material reveals its characteristic slight visco-elastic dissipation and heating as its lifetime was exhausted. Also, the obtained results of additively manufactured PA12 were compared with those of materials obtained by injection molding (IM) and extrusion techniques. The quasi-static flexural properties of PA12 obtained by FFF and SLS processes reveal better characteristics compared to IM and extruded specimens. However, the fatigue properties of the SLS-processed polymer are 24% and 40% less than those of materials obtained by IM and extrusion.