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Nonwoven media used as electret air filters are often embedded with charges to improve particle capture efficiency. These charged filters are invariably exposed to low surface tension fluids such as oils and alcohols leading to charge loss. In this study, filtration media are endowed with charge protection through increased surface repellency using melt additives that can migrate to the surface during processing. Nonwovens containing fluorochemical melt additives are produced, and examined to determine the relationship between surface chemistry, isopropyl alcohol (IPA) repellency, resultant charge retention, and filtration characteristics. Surface fluorine/carbon (F/C) ratios of ≈0.2 are sufficient to protect filtration performance from vapor discharging methods. Samples with bulk additive loadings of 1.2% or higher are found to achieve the necessary repellency to resist discharging independent of the migration state of the sample, while samples loaded at the 0.6% level required sufficient migration to achieve the requisite F/C ratio of 0.2 in order to be protected. Samples that achieved the necessary surface chemistry to provide significant IPA repellency retained > 80% of electret charge and corresponding filtration performance. These results have special significance in the design of filtration media relevant in global healthcare and other industrial settings. [ABSTRACT FROM AUTHOR]

Responsive photonic crystals have attracted significant attention in fundamental scientific research and technological applications. Upon applying external stimuli, such as mechanical, electrical, magnetic, and optical triggers, the optical properties of photonic crystals can be actively tuned. Among a large number of photonic crystals, cellulose nanocrystals (CNCs) are considered one of the most promising materials due to their renewability, simplicity of preparation, and unprecedented chirality. A comprehensive overview of the fundamental design principles, methodologies, responsive mechanisms, and practical applications of responsive chiral photonic CNC materials is presented here. The changes in helix pitch, refractive index, orientation, and resulting structural and optical properties of chiral photonic CNCs in response to various stimuli are discussed. Thereafter, novel applications of responsive chiral photonic CNCs, such as colorimetric sensors, photonic actuators, rewritable photonic papers, and anti‐counterfeiting smart tags are described. We conclude by discussing future challenges and opportunities for developing high‐performance responsive chiral photonic CNC materials. [ABSTRACT FROM AUTHOR]

New strategies for the intensification of industrial electromembrane processes are needed, especially to reduce equipment size and operational costs. To intensify those processes and to decrease fouling and scale occurrence in such systems, we propose operation with very short asymmetric pulses (order of microseconds) of alternating polarity. Hence, a custom made Asymmetric Bipolar Switch was designed and built, operating with pulse widths in the 10-5-10-2 s range. Compared to traditional systems, we demonstrate the possibility of applying pulses with high intensities, up to three times higher than normal operation, using a frequency range between 0 (continuous operation) and 102 Hz. The proposed device was coupled to an electrodialysis cell for desalting a brine solution. When switching in desalination, a Back Electrochemical Force was identified, which could affect the integrity of the electronic systems due to spikes of reverse voltage. Hence, mitigation strategies were applied by changing the switching logic and incorporating new elements in the circuitry, similar to those in breaking methods in electrical motors. While desalting in electrodialysis, the experiments showed a limited power loss, up to 0.6% of the total power applied, attributed mainly to electrical disturbance (conduction and switching losses in the electronic components were minor at this scale). No significant variation in the desalination performance was observed at low current densities. The designed Asymmetric Bipolar Switch opens new possibilities for the operation with electromembranes and other electrochemical processes. [ABSTRACT FROM AUTHOR]

Liquid metal (LM) nanodroplets and MXene nanosheets are integrated with sulfonated bacterial nanocellulose (BNC) and acrylic acid (AA). Upon fast sonication, AA polymerization leads to a crosslinked composite hydrogel in which BNC exfoliates Mxene, forming organized conductive pathways. Soft conducting properties are achieved in the presence of colloidally stable core-shell LM nanodroplets. Due to the unique gelation mechanism and the effect of Mxene, the hydrogels spontaneously undergo surface wrinkling, which improves their electrical sensitivity (GF = 8.09). The hydrogels are further shown to display interfacial adhesion to a variety of surfaces, ultra-elasticity (tailorable elongation, from 1000 % to 3200 %), indentation resistance and self-healing capabilities. Such properties are demonstrated in wearable, force mapping, multi-sensing and patternable electroluminescence devices. [Display omitted] • Nanocellulose-supported LM/MXene composite hydrogels are formed by one-step sonication. • The polymer matrix effectively disperses core-shell LM nanodroplets and MXene nanosheets. • The hydrogels display ultra-elasticity, indentation resistance and self-healing properties. • The composite hydrogel is demonstrated for sensing, force mapping and electroluminescence. [ABSTRACT FROM AUTHOR]

The composition and physical-chemical properties of the milk fat globule membrane (MFGM) is a subject that has gained increased interest in the field of food colloids, mainly because the nutritional and technological value of the MFGM. In fact, related changes in integrity and structure during milk processing pose a huge challenge as far as efforts directed to isolate the components of the fat globule membrane. MFGM characteristics and potential utilization are subjects of dissension. Thus, the effects of processing and the colloidal interactions that exist with other milk constituents need to be better understood in order to exploit milk fat and MFGM, their functionality as colloids as well as those of their components. These are the main subjects of this review, which also reports on the results of recent inquiries into MFGM structure and colloidal behavior. [ABSTRACT FROM AUTHOR]

Despite being non-surface active, nanocelluloses position efficiently at interfaces, already at very low concentration. This behavior has lately triggered a strong interest in the cellulose and colloids communities. This review reports the recent developments on the use of nanocelluloses at interfaces and highlights the fundamental principles governing the high efficiency observed in reinforcing the boundary between two phases. The use of nanocelluloses as emulsifier and emulsion stabilizer is first discussed, and the structural properties of nanocelluloses such as aspect ratio and surface properties are correlated with the high efficiency in forming colloidally-stable multiphase systems. Then, the behavior at the air/water interface is presented and the most recent advances are reviewed with focus on the surface free energy of nanocelluloses and their role in the interfacial self-assembly process. [ABSTRACT FROM AUTHOR]

C-reactive protein (CRP) is an acute phase protein that has been widely used as a predictor of cardiovascular diseases. We report herein the synthesis of immunosensors based on carboxylated cellulose nanofibrils (CNF) for CRP detection, as demonstrated by quartz crystal microgravimetry (QCM). QCM sensors carrying ultrathin films of carboxylated CNF were prepared by using two protocols: (i) spin coating of CNF on the sensors followed by carboxylation via in situ oxidation with 2,2,6,6-tetramethylpiperidine 1-oxyl and (ii) carboxymethylation of CNF in aqueous dispersion followed by spin coating deposition on the sensors. Protein A was conjugated to the carboxylated CNF via N-(3-(Dimethylamino)propyl)-N′-ethylcarbodiimide hydrochloride/N-hydroxysuccinimide and used as a ligand for oriented immobilization of anti C-reactive protein (anti-CRP). The different carboxyl group density of the two oxidized CNF surfaces influenced Protein A binding and, subsequently, the available immobilized anti-CRP molecules. The detection efficiency for CRP, specificity, and concentration range displayed by the carboxylated CNF-based immunosensors coupled with oriented and unoriented anti-CRP were determined and compared. [ABSTRACT FROM AUTHOR]

Biogenic silica derived from Equisetum arvense was used as a carrier of an eco-friendly biocide consisting of a neem bark extract cross-linked with polycarboxylic acids. Infrared spectroscopy indicated the presence of ester bonds between the silica support and the loaded bark extract. Surface area analysis, porosimetry and microscopy confirmed a high level of biocide loading in the silica support. Furthermore, compared with the unloaded biogenic silica nanoparticles, a better thermal stability was determined for the system carrying the extracted compounds. Experiments consisting of three sequential release profiles showed full mass release after 20 days of unloaded neem while the extract loaded in the solid support reached only 60–75% released after 30 days. A four-fold improvement in the neem extract stability was observed in aqueous media if loaded in the silica support. The neem compounds released from silica showed a satisfactory scavenging activity over 50% of DPPH free radical, and could cause the mortality of the major workers of Acromyrmex crassispinus ant specie. [ABSTRACT FROM AUTHOR]

Biogenic silica from Equisetum arvense was dispersed in aqueous media by using ball milling, high-energy planetary ball milling and ultrasonication. Zeta potential (ζ), dynamic light scattering, and transmission electron microscopy revealed the electrostatic charge and morphological characteristics of the particles, which formed stable colloidal dispersions. Ball milling and ultrasonication yielded particles of 10 nm in size that clustered into larger structures. Extended milling time was effective in reducing the particle size by ball milling and ultrasonication but not by high-energy planetary ball milling. The colloidal stability of the dispersions was maximized under alkaline conditions (ζ > − 30 mV and smallest cluster size of 100–200 nm). [ABSTRACT FROM AUTHOR]

Many current and potential uses of cellulosic materials depend critically on the character of their surfaces. This review of the scientific literature considers both well-established and emerging strategies to change the outermost surfaces of cellulosic fibers or films not only in terms of chemical composition, but also in terms of outcomes such as wettability, friction, and adhesion. A key goal of surface modification has been to improve the performance of cellulosic fibers in the manufacture of composites through chemistries such as esterification that are enabled by the high density of hydroxyl groups at typical cellulosic surfaces. A wide variety of grafting methods, some developed recently, can be used with plant-derived fibers. The costs and environmental consequences of such treatments must be carefully weighed against the potential to achieve similar performances by approaches that use more sustainable methods and materials and involve less energy and processing steps. There is potential to change the practical performances of many cellulosic materials by heating, by enzymatic treatments, by use of surface-active agents, or by adsorption of polyelectrolytes. The lignin, hemicelluloses, and extractives naturally present in plant-based materials also can be expected to play critical roles in emerging strategies to modify the surfaces characteristics of cellulosic fibers with a minimum of adverse environmental impacts. [ABSTRACT FROM AUTHOR]

In this work, a conductive hydrogel was successfully synthesized, taking advantage of the high number density of active amino and hydroxyl groups in carboxymethyl chitosan and sodium carboxymethyl cellulose. These biopolymers were effectively coupled via hydrogen bonding with the nitrogen atoms of the heterocyclic rings of conductive polypyrrole. The inclusion of another biobased polymer, sodium lignosulfonate (LS), was effective to achieve highly efficient adsorption and in-situ reduction of silver ions, leading to silver nanoparticles that were embedded in the hydrogel network and used to further improve the electro-catalytic efficiency of the system. Doping of the system in the pre-gelled state led to hydrogels that could be easily attached to the electrodes. The as-prepared silver nanoparticle-embedded conductive hydrogel electrode exhibited excellent electro-catalytic activity towards hydroquinone (HQ) present in a buffer solution. At the optimum conditions, the oxidation current density peak of HQ was linear over the 0.1–100 μM concentration range, with a detection limit as low as 0.12 μM (signal-to-noise of 3). The relative standard deviation of the anodic peak current intensity was 1.37% for eight different electrodes. After one week of storage in a 0.1 M Tris-HCl buffer solution at 4 °C, the anodic peak current intensity was 93.4% of the initial current intensity. In addition, this sensor showed no interference activity, while the addition of 30 μM CC, RS, or 1 mM of different inorganic ions does not have a significant impact on the test results, enabling HQ quantification in actual water samples. [ABSTRACT FROM AUTHOR]

We evaluated the effect of polyelectrolyte complexes (PEC) with varying balance of charges on the flocculation of precipitated calcium carbonate (PCC) particles. PECs composed of polyacrylamides carrying opposite charges (A-PAM and C-PAM) were investigated in terms of PCC floc shear resistance and re-flocculation effects. Light transmission was used in real time to monitor the dynamics of flocculation under shear fields. Compared to the single polyelectrolytes, PECs greatly enhanced particle re-flocculation while minor differences in shear resistance were observed. Shear resistance and re-flocculation depended strongly on the molecular weight and charge ratio of the PEC components. In order to achieve floc stability and re-flocculation conditions a minimum concentration of charge-asymmetric PEC should be applied. [ABSTRACT FROM AUTHOR]

Adhesive-free fiberboards can be self-bonded through high temperature thermo-compression processes. To achieve it, treatments such as steam explosion/injection, as well as chemical and enzymatic oxidation have been implemented. However, the role of extractive components in the structure and cohesiveness of fiberboards has not been fully understood. In this work fibers of leaf plantain were treated with organic solvents and with hot water to remove the extractives, and were then employed to produce self-bonded fiberboards. Treated fibers were characterized by thermogravimetric analysis, electronic paramagnetic resonance, and antioxidant capacity. The mechanical strength of the fiberboards evaluated by three point flexural tests, decreased when fibers were extracted with aqueous solvents, and increased after treatment with organic ones. This can be explained by the effect of water extractives in reducing the initial degradation temperature, and in retaining free stable radicals generated during thermo-compression. In the case of the organic extractive fraction, this inactivates the fibers, which impairs close contact between polar groups and thus decreases the mechanical properties of the fiberboards. According to the results, it is possible to increase the mechanical properties of self-bonded fiberboards by changing the concentration of polar and low molecular weight phenolic compounds. [ABSTRACT FROM AUTHOR]

The present work attempts to providedata to warrant the considerationof soy proteins (SP) as potentially useful biomolecules for practicalchemical and surface applications. Despite their sundry properties,SP use has been limited by their high molecular weight. In responseto this limitation, we analyze acid hydrolysates of soy proteins (0.1N HCl, 70 °C) for surface modification. Techniques typical inprotein (SDS-PAGE) as well as colloidal (charge demand and electrophoreticmobility) analyses were used to follow the effects of molecular changesthat occur upon hydrolysis. Adsorption experiments on hydrophobic(polypropylene) and mineral (aluminum oxide) surfaces were subsequentlycarried out to further interrogate the surface activity resultantfrom soy hydrolysis. It was found that during adsorption the hydrolysatestended to form less surface aggregates and adsorbed at faster ratescompared with unmodified SP. Overall, the benefits derived from theapplication of SP hydrolysates are highlighted. [ABSTRACT FROM AUTHOR]

Moleculardynamics simulations were used to characterize the wettingbehavior of crystalline cellulose planes in contact with a thin oilyfilm of oleic acid. Cellulose crystal planes with higher molecularprotrusions and increased surface area produced stronger adhesionif compared to other crystal planes due to enhanced wetting and hydrogenbonding. The detailed characteristics of crystal plane features andthe contribution of directional hydrogen bonding was investigated.Similarly, oleophilicity of the cellulose planes increased with theincrease in surface roughness and number of directional hydrogen bonds.These results correlate with conclusions drawn from experimental studiessuch as adhesion of an ink vehicle on cellulose surface. [ABSTRACT FROM AUTHOR]

Water-insoluble oils, including crude petroleum and a wide variety of refined organic liquids, can cause major problems if spilled or leaked to aqueous environments. Potential environmental damage may be reduced if the spilled oil is promptly and efficiently removed from the water. This article reviews research that sheds light on the use of cellulose-based materials as sorbents to mitigate effects of oil spills. Encouraging results for oil sorption have been reported when using naturally hydrophobic cellulosic fibers such as unprocessed cotton, kapok, or milkweed seed hair. In addition, a wide assortment of cellulosic materials have been shown to be effective sorbents for hydrocarbon oils, especially in the absence of water, and their performance under water-wet conditions can be enhanced by various pretreatments that render them more hydrophobic. More research is needed on environmentally friendly systems to handle oil-contaminated sorbents after their use; promising approaches include their re-use after regeneration, anaerobic digestion, and incineration, among others. Research is also needed to further develop combined response systems in which biosorption is used along with other spill-response measures, including skimming, demulsification, biodegradation, and the use of booms to limit the spreading of oil slicks. [ABSTRACT FROM AUTHOR]

We describe the formation of amphiphilic polymeric assembliesviaa three-step functionalization process applied to polypropylene (PP)nonwovens and to reference hydrophobic self-assembled n-octadecyltrichlorosilane (ODTS) monolayer surfaces. In the firststep, denatured proteins (lysozyme or fibrinogen) are adsorbed ontothe hydrophobic PP or the ODTS surfaces, followed by cross-linkingwith glutaraldehyde in the presence of sodium borohydride (NaBH4). The hydroxyl and amine functional groups of the proteinspermit the attachment of initiator molecules, from which poly (2-hydroxyethylmethacrylate) (PHEMA) polymer grafts are grown directly through “graftingfrom” atom transfer radical polymerization. The terminal hydroxylsof HEMA’s pendent groups are modified with fluorinating moietiesof different chain lengths, resulting in amphiphilic brushes. A paletteof analytical tools, including ellipsometry, contact angle goniometry,Fourier transform infrared spectroscopy in the attenuated total reflectionmode, and X-ray photoelectron spectroscopy is employed to determinethe changes in physicochemical properties of the functionalized surfacesafter each modification step. Antifouling properties of the resultantamphiphilic coatings on PP are analyzed by following the adsorptionof fluorescein isothiocyanate-labeled bovine serum albumin as a modelfouling protein. Our results suggest that amphiphilic coatings suppresssignificantly adsorption of proteins as compared with PP fibers orPP surfaces coated with PHEMA brushes. The type of fluorinated chaingrafted to PHEMA allows modulation of the surface composition of thetopmost layer of the amphiphilic coating and its antifouling capability. [ABSTRACT FROM AUTHOR]

X‐ray photoelectron spectroscopy (XPS) was employed to quantify adsorption of polyelectrolytes from aqueous solutions of low ionic strength onto mica, glass, and silica. Silica surfaces were conditioned in base or in acid media as last pre‐treatment step (silica‐base last or silica‐acid last, respectively). Consistency in the determined adsorbed amount, Γ, was obtained independent of the choice of XPS mode and with the two quantification approaches used in the data evaluation. Under the same adsorption conditions, the adsorbed amount, Γ, varied as Γmica > Γsilica‐base last ≈ Γglass > Γsilica‐acid last. In addition, the adsorbed amount increased with decreasing polyelectrolyte charge density (100% to 1% of segments being charged) for all substrates. Large adsorbed amount was measured for low‐charge density polyelectrolytes, but the number of charged segments per square nanometer was low due to steric repulsion between polyelectrolyte chains that limited the adsorption. The adsorbed amount of highly charged polyelectrolytes was controlled by electrostatic interactions and thus limited to that needed to neutralize the substrate surface charge density. For silica, the adsorbed amount depended on the cleaning method, suggesting that this process influenced surface concentration and fraction of different silanol groups. Our results demonstrate that for silica, a higher density and/or more acidic silanol groups are formed using base, rather than acid, treatment in the last step. [ABSTRACT FROM AUTHOR]

Hydrophilic coatings were produced on flat hydrophobicsubstratesfeaturing n-octadecyltrichlorosilane (ODTS) and syntheticpolypropylene (PP) nonwoven surfaces through the adsorption of denaturedproteins. Specifically, physisorption from aqueous solutions of α-lactalbumin,lysozyme, fibrinogen, and two soy globulin proteins (glycinin andβ-conglycinin) after chemical (urea) and thermal denaturationendowed the hydrophobic surfaces with amino and hydroxyl functionalities,yielding enhanced wettability. Proteins adsorbed strongly onto ODTSand PP through nonspecific interactions. The thickness of adsorbedheat-denatured proteins was adjusted by varying the pH, protein concentrationin solution, and adsorption time. In addition, the stability of theimmobilized protein layer was improved significantly after interfacialcross-linking with glutaraldehyde in the presence of sodium borohydride.The amino and hydroxyl groups present on the protein-modified surfacesserved as reactive sites for the attachment of polymerization initiatorsfrom which polymer brushes were grown by surface-initiated atom-transferradical polymerization of 2-hydroxyethyl methacrylate. Protein denaturationand adsorption as well as the grafting of polymeric brushes were characterizedby circular dichroism, ellipsometry, contact angle, and Fourier transforminfrared spectroscopy in the attenuated total reflection mode. [ABSTRACT FROM AUTHOR]

Soybean proteins have found uses in different nonfoodapplicationsdue to their interesting properties. We report on the kinetics andextent of adsorption on silica and cellulose surfaces of glycininand β-conglycinin, the main proteins present in soy. Quartzcrystal microgravimetry (QCM) experiments indicate that soy protein adsorptionis strongly affected by changes in the physicochemical environment.The affinity of glycinin and the mass adsorbed on silica and celluloseincreases (by ca. 13 and 89%, respectively) with solution ionic strength(as it increases from 0 to 100 mM NaCl) due to screening of electrostaticinteractions. In contrast, β-conglycinin adsorbs on the samesubstrates to a lower extent and the addition of electrolyte reducesadsorption (by 25 and 57%, respectively). The addition of 10 mM 2-mercaptoethanol,a denaturing agent, reduces the adsorption of both proteins with asignificant effect for glycinin. This observation is explained bythe cleavage of disulfide bonds which allows unfolding of the moleculesand promotes dissociation into subunits that favors more compact adsorbedlayer structures. In addition, adsorption of glycinin onto cellulosedecreases with lowering the pH from neutral to pH 3 due to dissociationof the macromolecules, resulting in flatter adsorbed layers. The respectiveadsorption isotherms fit a Langmuir model and QCM shifts in energydissipation and frequency reveal multiple-step kinetic processes indicativeof changes in adlayer structure. [ABSTRACT FROM AUTHOR]

Abstract: Polyampholytes, which are macromolecules that contain both positive and negative ionizable groups, can provide superior strength improvements for paper manufacture, compared to the addition of simple polyelectrolytes. Colloidal effects, which were measured in solution and in fiber suspensions, were consistent with observed bonding effects. The same colloidal effects were found to correlate with the effects of pH and of the density of the ionizable groups on the polyampholytes. Tests were carried out with a series of polyampholytes having a constant ratio of cationic to anionic monomeric groups and molecular mass. Their charge density varied in the ratio 1:2:4:8. The greatest strength gains were obtained at intermediate charge density and under conditions of pH favoring instability of the aqueous polymer mixtures. Colloidal phenomena were elucidated by turbidimetric tests, sediment volumes of treated fiber suspensions, flocculation tendencies of treated fiber suspensions, and zeta potentials of probe particles. [Copyright &y& Elsevier]

Abstract: In this study we show, for the first time, that the streaming potential of aqueous suspensions of nanoporous silica gel, after treatment with the cationic polyelectrolyte poly-diallyldimethylammonium chloride (poly-DADMAC), can depend very strongly on the concentration of background electrolyte. An increase in the electrical conductivity from 60 to 1000μS/cm resulted in an approximately 1000-fold increase in the amount of poly-DADMAC that was required to reach an endpoint of zero streaming potential. Results were explained by two contributions to the overall electrokinetic behavior—one due to the outer surfaces and another due to the interior surfaces of nanopore spaces that were inaccessible to the polyelectrolytes. Experiments with cyclical changes in salt content revealed a high degree of reversibility; such observations help to rule out explanations based on salt-induced desorption or enhancement of pore penetration. Supplementary tests with non-porous glass fibers showed no evidence of the distinctive electrokinetic behavior observed in the case of nanoporous particles. Effects of polymer molecular mass and pH, evaluated under similar experimental conditions, agreed with well-established trends. [Copyright &y& Elsevier]

The adoption of hydrogels in most applications is hampered by their high free water content, which limits their mechanical performance and environmental resilience. Herein, this issue is simultaneously addressed by modulating the state of water and the intermolecular interactions in polyacrylamide (PAM) hydrogels. Specifically, PAM hydrogels are toughened by sugaring‐out using a monosaccharide (glucose, G). Glucose is found to facilitate PAM hydrogen bonding and interchain interactions. Meanwhile, the high hygroscopicity of glucose converts some of the free water to bound state, endowing the hydrogels with remarkable resilience to extreme environmental conditions. The PAM‐G hydrogels are demonstrated as multimodal sensors for soft robotics. Moreover, PAM‐G alcogels produced by solvent exchanging with ethanol are shown as effective opto‐mechanical sensors. Notably, all these properties are obtained by the inclusion of glucose, a green additive showing no negative health and environmental effect. [ABSTRACT FROM AUTHOR]

We developed a highly sensitive solid-state sensor for mercury detection by stabilizing red-sub-nanometric fluorescent gold nanoclusters (AuNC, 0.9 ± 0.1 nm diameter) with bovine serum albumin in a matrix composed of cellulose nanofibrils (CNF) (BSA-AuNC/CNF). The main morphological and optical features of the system were investigated via atomic force/transmission electron microscopy and UV-Vis/fluorescence spectroscopy. The hybrid film (off-white and highly transparent) showed strong photoluminescene under UV irradiation. The latter is assigned to the AuNC, which also increase the ductility of the emitting film, which was demonstrated for high sensitivity Hg2+ detection. When used as a sensor system, following AuNC printing on CNF hybrid films, a limit of detection <10 nM was confirmed. What is more, nanocellulose films have a high pore structure and selective separation properties, showcasing a wide range of potential applications in many fields such as water treatment and oil–water separation. [ABSTRACT FROM AUTHOR]

The dissipation of charges by aging or under the effect of humid conditions considerably impedes a broader utilization of electrostatic fields in aerosol filtration. This study introduces a respiration‐driven air filter (RAF) that continuously generates triboelectric charges within a pair of tribolayers, which facilitates a sustained filtration performance. Such system is integrated in a multilayer unit that is inserted in personal protective equipment (RAFM) to efficiently capture, sense, and degrade airborne pollutants with no need for external power sources. The triboelectric nanogenerator‐based RAF continuously replenishes static charges and maintains an electrostatic field through breathing by the effect of contact‐electrification between two cellulose‐based tribolayers: a cellulose/metal organic framework cryogel (electron donor) and a cellulose–based electrospun membrane (electron acceptor). Notably, the triboelectric field of the RAF's tribolayer pair substantially enhances both the filtration efficiency (up to 93.8% for 0.3 µm particulate matter) and sensing/catalytic degradation (ammonia; degradation >20%). When integrated in a circuit module, the RAFM effectively monitors respiration dynamics, acting as a breathing indicator/regulator. Overall, this study adds to the promise of tribogeneration through cellulose‐based materials and its application in exposure‐risk operations. [ABSTRACT FROM AUTHOR]

Interfacial jamming and assembly, facilitated by nanoparticle surfactant (NPS) complexation, demonstrate a remarkable efficacy in stabilizing multiphase systems, evident in structured liquid streams and structured Pickering emulsions. However, the utilization of structured liquid templates to tune multiple porosity levels of ultra‐flyweight aerogels is barely discussed. In this study, a structured Pickering emulsion is prepared through mixing an aqueous dispersion of graphene oxide (GO) with an organic (hexane) solution containing an active ligand. The emulsion is jetted into the same organic phase, resulting in “dual jamming”. This process produced worm‐like aerogels with porosity that can be precisely tailored at four different levels: i) voids between filaments, ii) cavities produced by evaporation of trapped hexane droplets, iii) pores generated from sublimation of water in the bulk of GO emulsion, and iv) microscopic regions trapped between GO flakes or fractures/holes within GO nanosheets. These aerogels exhibit ultra‐low density (1.67–2.3 mg cm−3), high compressibility, and shape recovery. The multi‐scale porosity, created by structural design, endows aerogels with a record‐level fluid sorption capacity (e.g., 615 g g−1 for chloroform). Additionally, the aerogels demonstrate an absorption‐dominant electromagnetic interference (EMI) shielding mechanism, achieving a remarkable specific EMI shielding (SSE/t) of 67 178 dB cm2 g−1. [ABSTRACT FROM AUTHOR]

Changing trends in packaging materials has been driven by increasing environmental awareness as well as legislation. In this context, paperboard-based packaging have become increasingly popular due to its bio-based origin, potential biodegradability and physical properties. However, conventional systems lack behind in barrier performance and heat sealability. Hence, the addition of functional layers have been considered as alternative solutions to this challenge. Here we propose a biodegradable PLA-based polymer coating filled with minerals (0–10 wt% loading), namely, talc, kaolin and calcium carbonate, all of which were used in surface application on uncoated folding box board. For this purpose, we used a pilot-scale extrusion unit that produced materials that were tested for key properties. We found that the presence of filler in the PLA layer improved both water vapor (up to 16 %) and oxygen (up to 56 %) barrier properties. Moreover, the main effect of the fillers was observed in heat sealability, which was improved via adhesion at low temperatures, resulting in full fiber tear. Cup forming was less effected by filler loading in the PLA coating while repulping tests indicated the presence of large flakes of the polymer coating in 1 %-consistency slurries. Finally, biodegradability was slightly delayed in filler-containing samples (biodegradation within 10–60 days), most likely due to the nucleating effect of the fillers. Nevertheless, all the samples can be classified as biodegradable. Overall, our results represent a step forward in scale-up adoption of PLA-based coatings most useful in the development of packaging materials. [ABSTRACT FROM AUTHOR]

Site-specific assembly of gold nanoparticles on a polysaccharide surface was accomplished via a straightforward method exploiting interfacial polymer blends, selective protein adsorption and electrostatic interaction. The method could be useful in further applications due to the universal nature of the utilized phenomena. [ABSTRACT FROM AUTHOR]

This study elucidates the intricate interactions between chitin nanocrystals (ChNC) and surfactants of same hydrophobic tail (C 12) but different head groups types (anionic, cationic, nonionic): sodium dodecyl sulfate (SDS), dodecyltrimethylammonium bromide (DTAB), and polyoxyethylene(23)lauryl ether (Brij-35). Isothermal Titration Calorimetry (ITC) and rheology are used to study the complex ChNC-surfactant interactions in aqueous media, affected by adsorption, self-assembly and micellization. The ITC results demonstrate that the surfactant head group significantly influences the dynamics and nature of the involved phenomena. Cationic DTAB's reveal minimal interaction with ChNC, non-ionic Brij-25's interact moderately at low concentrations driven by hydrophobic effects while SDS's interacts strongly and show complex interaction patterns that fall across four distinct regimes with SDS addition. We attribute such behavior to initiate through electrostatic attraction and terminate in surfactant micelle formation on ChNC surfaces. ITC also elucidates the impact of ChNC concentration on key parameters including critical aggregation concentration (CAC) and saturation concentration (C 2). Dynamic rheological analysis indicates the molecular interactions translate to non-linear variations in the elastic modulus (G') upon SDS addition mirroring that observed in ITC experiments. Such a direct correlation between molecular interactions and macroscopic rheological properties provides insights to aid in the creation of nanocomposites with tailored properties. [Display omitted] [ABSTRACT FROM AUTHOR]

Electrodialysis (ED) intensification is introduced by application of asymmetric pulses of reverse polarity. Very short pulses (10 to 100 μs) at high frequencies (from 100 to 4000 Hz) were tested, modulating the amplitude of the pulses to adjust energy consumption. Their effect in Limiting Current Density (LCD) and resulting desalination performance were investigated under various operation modes. To fully exploit electroconvective vortices, oscilloscopic profiles were used to optimize the pulsed operation. Under such conditions, the LCD increased by up to 1.6 times compared to conventional ED. The results demonstrate an effective intensification of the desalination process using pulsed electrodialysis reversal (pEDR), with a significantly reduced time in overlimiting regimes (~43% less time compared with sub-limiting conditions), while maintaining a stable pH during the operation. The energy consumed under such overlimiting current conditions, however, increased by ~56% or 14% compared to conventional ED at sub-limiting or overlimiting current regimes, respectively. This new strategy for desalination is expected to decrease the capital costs of ED plants given the prospects of operation under reduced equipment sizes. • An asymmetric bipolar switch device is coupled to electrodialysis to intensify desalination. • Very short pulses of reverse polarity at high frequencies promote electroconvective vortices. • The application of bipolar pulses accelerates desalination, although increases energy consumption. • Electrodialysis can be run in overlimiting current regimes without being affected by pH instabilities. • It is possible to optimize the operation by varying frequency, duration and amplitude of the bipolar pulses. [ABSTRACT FROM AUTHOR]

[Display omitted] Waterborne sulfopolyesters have gained considerable interest as coating materials due to their excellent film-forming and optical properties. Their commercial use has been limited, however, due to their fragile nature. Incorporating cellulose nanofiber (CNF), a sustainable biopolymer, into the polymer matrix is expected to enhance the mechanical integrity of the nanocomposite as these two components synergistically interact. In this study, we have investigated the suspension and film characteristics of three sulfopolyesters varying in charge density, glass transition temperature and molecular weight, as well as their mixtures with CNF. We have performed steady-shear rheology on mixtures with different CNF loading levels, and resulting films have been subjected to quasistatic uniaxial tensile and water contact-angle tests to elucidate the effects of CNF on mechanical and surface properties. Addition of CNF to waterborne polyester promotes shear-thinning behavior that remains unaffected by the CNF content. Solid films cast from these suspensions possess enhanced mechanical properties, as well as tailorable surface hydrophilicity, depending on composition and film-drying temperature. Tensile tests reveal that films containing 10 wt% CNF display the greatest mechanical improvements, suggesting the existence of a previously unidentified Goldilocks composition window. [ABSTRACT FROM AUTHOR]

Nanocellulose and nanochitin are both biobased materials with complementary structures and properties. Both exhibit pH-dependent surface charges which are opposite in sign. Hence, it should be possible to manipulate them to form complexed structures via ionic bond formation at prescribed pH conditions. Nanocellulose and nanochitin were mixed after exposure to acidic or neutral conditions to influence their ionization state. The heat of interaction during the introduction of nanochitin to nanocellulose was monitored via isothermal titration calorimetry. The strength and gel properties of the resulting structures were characterized via rheological measurement. The resultant gel properties in the designed hybrid systems were found to depend directly on the charge state of the starting materials, which was dictated by pH adjustment. Different interparticle interactions including ionic attraction, hydrophobic associations, and physical entanglement were identified in the systems and the influence of each was elucidated for different conditions of pH, concentration, and ratio of nanochitin to nanocellulose. Hydrophobic associations between neutralized nanochitin particles were found to contribute strongly to increased elastic modulus values. Ionic complex formation was found to provide enhanced stability under broader pH conditions, while physical entanglement of cellulose nanofibers was a substantial thickening mechanism in all systems. [ABSTRACT FROM AUTHOR]

The demand for biodegradable materials across various industries has recently surged due to environmental concerns and the need for the adoption of renewable materials. In this context, lignin has emerged as a promising alternative, garnering significant attention as a biogenic resource that endows functional properties. This is primarily ascribed to its remarkable origin and structure that explains lignin's capacity to bind other molecules, reinforce composites, act as an antioxidant, and endow antimicrobial effects. This review summarizes recent advances in lignin-based composites, with particular emphasis on innovative methods for modifying lignin into micro and nanostructures and evaluating their functional contribution. Indeed, lignin-based composites can be tailored to have superior physicomechanical characteristics, biodegradability, and surface properties, thereby making them suitable for applications beyond the typical, for instance, in ecofriendly adhesives and advanced barrier technologies. Herein, we provide a comprehensive overview of the latest progress in the field of lignin utilization in emerging composite materials. [ABSTRACT FROM AUTHOR]

MXene and graphene cryogels have demonstrated excellent electromagnetic interference (EMI) shielding effectiveness due to their exceptional electrical conductivity, low density, and ability to dissipate electromagnetic waves through numerous internal interfaces. However, their synthesis demands costly reduction techniques and/or pre‐processing methods such as freeze‐casting to achieve high EMI shielding and mechanical performance. Furthermore, limited research has been conducted on optimizing the cryogel microstructures and porosity to enhance EMI shielding effectiveness while reducing materials consumption. Herein, a novel approach to produce ultra‐lightweight cryogels composed of Ti3C2Tx/graphene oxide (GO) displaying multiscale porosity is presented to enable high‐performance EMI shielding. This method uses controllable templating through the interfacial assembly of filamentous‐structured liquids that are readily converted into EMI cryogels. The obtained ultra‐flyweight cryogels (3–7 mg cm−3) exhibit outstanding specific EMI shielding effectiveness (33 000–50 000 dB cm2 g−1) while eliminating the need for chemical or thermal reduction. Furthermore, exceptional shielding is achieved when the Ti3C2Tx/GO cryogels are used as the backbone of conductive epoxy nanocomposites, yielding EMI shielding effectiveness of 31.7–51.4 dB at a low filler loading (0.3–0.7 wt%). Overall, a one‐of‐a‐kind EMI shielding system is introduced that is readily processed while affording scalability and performance. [ABSTRACT FROM AUTHOR]

[Display omitted] Biomaterials such as collagen and tannic acid (TA) particles are of interest in the development of advanced hybrid biobased systems due to their beneficial therapeutic functionalities and distinctive structural properties. The presence of numerous functional groups makes both TA and collagen pH responsive, enabling them to interact via non-covalent interactions and offer tunable macroscopic properties. The effect of pH on the interactions between collagen and TA particles is explored by adding TA particles at physiological pH to collagen at both acidic and neutral pH. Rheology, isothermal titration calorimetry (ITC), turbidimetric analysis and quartz crystal microbalance with dissipation monitoring (QCM-D) are used to study the effects. Rheology results show significant increase in elastic modulus with an increase in collagen concentration. However, TA particles at physiological pH provide stronger mechanical reinforcement to collagen at pH 4 than collagen at pH 7 due to the formation of a higher extent of electrostatic interaction and hydrogen bonding. ITC results confirm this hypothesis, with larger changes in enthalpy, |Δ H |, observed when collagen is at acidic pH and |Δ H | > | T Δ S | indicating enthalpy-driven collagen-TA interactions. Turbidimetric analysis and QCM-D help to identify structural differences of the collagen-TA complexes and their formation at both pH conditions. [ABSTRACT FROM AUTHOR]

A renewable source of carbon black is introduced by the processing of lignin from agro‐forestry residues. Lignin side streams are converted into spherical particles by direct aerosolization followed by carbonization. The obtained submicron black carbon is combined with cellulose nanofibers, which act as a binder and rheology modifier, resulting in a new type of colloidal bioink. The bioinks are tested in handwriting and direct ink writing. After consolidation, the black bioinks display total light reflectance (%R) at least three times lower than commercial black inks (reduction from 12 to 4%R). A loading of up to 20% of nanofibers positively affects the cohesion of the dried bioink (1 to 16 MPa), with no significant reduction in light reflectance. This is a result of the superstructuring of the ink components, which disrupts particle packing, intensifies colloidal interactions, introduces light absorption, and non‐reflective multiple scattering. [ABSTRACT FROM AUTHOR]

X‐ray photoelectron spectroscopy (XPS) has become popular for polymeric and biological surface analysis. However, several experimental factors may bias XPS data interpretation. Ex situ contamination, outgassing, reactions due to ultra‐high vacuum or X‐ray exposure, and charging problems are not uncommon. They are reflected in the high variability of data quality of recent reports. In order to enhance the reliability and reproducibility of XPS data, especially for organics and polymers, a suitable in situ reference material would be of a great help. At Aalto's CHEM XPS laboratory, we use 100% cellulosic filter paper as a reference for all XPS experiments. Nature derived macrofibrillar cellulose is not an obvious candidate for an in situ reference material in XPS; however, it is not only the most abundant biopolymer on the biosphere but it also qualifies surprisingly well as a generic in situ XPS reference. [ABSTRACT FROM AUTHOR]

[Display omitted] • A biocomposite is produced through green and sustainable technologies. • 3D hybrid network structures incorporate coordination-driven silver nanoparticles. • The composite is multifunctional and efficient to reduce electromagnetic pollution. • Outstanding shielding effectiveness (∼30.8 dB) is realized. • Surface modification is inspired by epiphytes. With the development of advanced communication systems, paralleled with recent efforts to adopt lightweight, low-carbon footprint materials, there is an urgent demand for green electromagnetic interference (EMI) shielding materials. However, this is challenged by the shielding effectiveness of bio-based EMI and their capacity to eliminate radiation pollution while meeting the demands of diverse application environments. Learning from the strategies used by epiphytes, we introduce a highly efficient and multi-functional bio-based EMI shielding eco-material. We developed 3D hybrid network structures incorporating coordination-driven silver nanoparticles to achieve excellent shielding effectiveness, ∼30.8 dB, while simultaneously meeting mechanical demands, multi-functionality, water resistance, flame retardancy, and antibacterial properties. Overall, this work provides a novel but practical pathway to implement bio-based materials conferred with EMI protection, applicable in next-generation electronics. [ABSTRACT FROM AUTHOR]

Recent advances in ordered porous materials, including metal‐organic (MOF) and covalent organic frameworks (COF), are set to revolutionize the strategies used for wastewater treatment. This is attributed to the large surface area, high crystallinity, structural tunability, thermal and chemical stability, and well‐defined structures of MOF and COF. Despite the distinctive properties exhibited by the single system (either MOF or COF), the combination of COF and MOF, as a hybrid construct, offers a remarkable opportunity to achieve superior functionality and performance. The favorable features of COF–MOF hybrids in different wastewater treatment sectors have opened new venues for effective environmental remediation. This review presents the state‐of‐the‐art design, synthesis, and application of COF–MOF hybrids. The synthesis principles, including MOF‐first, COF‐first, and post‐synthetic linkage of pre‐synthesized COFs and MOFs are summarized. The potential of these novel materials is evaluated by considering contaminant sensing, adsorptive removal, and catalytic photodegradation.The conclusion is drawn by assessing the existing hurdles and potential opportunities in the development of COF‐MOF hybrids as an innovative yet viable approach for addressing wastewater treatment. [ABSTRACT FROM AUTHOR]

Drug-dependent design of hydrogels is currently required for engineering the controlled release of therapeutics, which is a major contributor to the technical challenges relating to the clinical translation of hydrogel-drug systems. Herein, by integrating supramolecular phenolic-based nanofillers (SPFs) into hydrogel microstructures we developed a facile strategy to endow a range of clinically relevant hydrogels with controlled release properties for diverse therapeutic agents. The assembly of multiscale SPF aggregates leads to tunable mesh size and multiple dynamic interactions between SPF aggregates and drugs, which relaxes the available choices of drugs and hydrogels. This simple approach allowed for the controlled release of 12 representative drugs evaluated with 8 commonly used hydrogels. Moreover, the anesthetic drug lidocaine was loaded into SPF-integrated alginate hydrogel and demonstrated sustained release for 14 days in vivo, validating the potential for long-term anesthesia in patients. [Display omitted] • Supramolecular phenolic-based nanofillers endow hydrogel multiscale porous structures. • Hydrogels release diverse therapeutic agents in a sustained and controlled manner. • Hydrogels achieve spatio-temporal control of drug release without case-by-case design. • This SPF strategy reduces the challenges to meet the drug-specific design criteria. • The modular assembly of SPF provides additional functionalities for hydrogel. [ABSTRACT FROM AUTHOR]

Leakage-free phase change materials (PCM) are used as passive energy storage systems that thermoregulate indoor environments. In this research, we synthesized highly porous hybrid materials based on non-covalent physical interactions between (poly)ethylene glycol (PEG) and modified cellulose nanofibrils (CNF), namely lignin-containing CNF (LCNF) or acetylated CNF (ACNF). The PEG/CNF hybrid, termed phase change nanohybrids (PCN), were ultra-lightweight (0.022–0.043 g/cm3), mechanically resilient, and displayed a high latent energy storage, up to 204 J/g. The PCN systems (specific heat capacity as high as 2.24 J/g K) were effective in thermal regulating 2.23 °C with a 1 mm thickness coverage while maintaining thermal stability. The PCN also demonstrated favorable thermal management under excess solar heating, providing 33.5 °C of insulative protection with a 1.5 cm thick system. The PCNs have exceptional acoustic absorbance (100% absorbance for 1600 Hz and 50% at lower frequencies, 500 Hz). Trace metal oxide (TiO 2) nanoparticles improved the PCN thermoregulating abilities, revealing desirable opportunities in multi-functional applications. Our biobased PCN is a promising insulation and passive energy storage alternative for thermal protection in smart building, electronic, packaging, energy storage system and aerospace sectors. [Display omitted] • Highly porous nanohybrids (PCNs) based on polyethylene glycol and modified nanocellulose. • The ultra-lightweight PCNs are mechanically resilient and provide high latent heat storage. • PCNs demonstrate favorable insulative protection under excess radiation heat. • PCNs have exceptional acoustic absorbance: 100% absorbance at 1600 Hz and 50% at lower frequencies. • TiO 2 nanoparticles improve PCNs' thermoregulating abilities towards multi-functionalities. [ABSTRACT FROM AUTHOR]

This study aims to overcome the challenges of high-value utilization of technical lignins that encounters chemical complexity, heterogeneity and broad molecular mass distribution. Kraft lignin was fractionated through a practical strategy involving sequential dissolution in solvents of different polarities (water, tetrahydrofuran, and water/tetrahydrofuran v/v = 3/7). Lignin self-assembled drawing on the anti-solvent method, generating particles of controllable surface energy. Considering the governing factors in multiphase stabilization, the morphology, wetting characteristics and chemical composition of the kraft lignin particles (KLPs) were examined as a means to achieve controllable Pickering stabilization of oil-in-water (O/W) emulsions. The most anionic and hydrophilic KLPs formed aggregated networks (∼185 nm), which acted as a surfactant-type emulsifier following reversible adsorption at the O/W interfaces. Notably, the particles of the least hydrophilicity (∼146 nm) displayed a characteristic hollow structure. Such particles adsorbed slowly and weakly at the O/W interface, forming a viscoelastic layer around the oil droplets. The smallest lignin particles (∼39 nm) presented an intermediate hydrophilic character. They were uniform in size and formed rigid interfacial layers on the oil droplets. Accordingly, the devised relationship between particle morphogenesis and O/W stabilization capacity enabled the customization of lignin (size and wetting characteristics), allowing broader utilization in multiphase systems. [ABSTRACT FROM AUTHOR]

The role of animal protein, casein, as compatibilizer and eco-friendly dispersant in composites comprising cellulose nanofibrils (CNF) and polylactic acid (PLA) was investigated. The effect of casein-mediated surface modification of PLA was validated with dynamic adhesion experiments that considered the contact area according to JKR approximation. In fact, a remarkable increase by ∼50% in the work of adhesion between CNF and PLA was observed after casein adsorption. It is likely that the improved adhesion gave rise to an enhanced dispersion of CNF and PLA within the composite matrix. Moreover, the mechanical properties of the respective nanocomposites were significantly improved. When compared to protein-free CNF/PLA nanocomposites, the systems containing casein indicated an enhanced extensibility (by 130%) and tensile toughness (by 60%) whereas tensile strength and Young's modulus were improved to a limited extent (6 and 12%, respectively). Finally, it is demonstrated that the surface modification of PLA with casein improves the compatibility between CNF and PLA, which is a prerequisite for the feasible preparation of 3D shaped cellulose-based packaging materials by direct thermoforming. [ABSTRACT FROM AUTHOR]

A buttermilk that is rich in functional components from milk fat globule membrane (MFGM) is of great interest to industry and consumers. However, isolation of such components is challenging because of the complexes they form with proteins. In this contribution, we describe a process, the ideal butter process, for separating milk fat globules and proteins in cream prior butter making to enhance MFGM deployment. First, raw and pasteurized bovine creams were micro-diafiltered with water using a tubular ceramic membrane. A 1.4 µm pore size was selected for the membrane to separate proteins and fat globules. Two trans-membrane pressures (0.4 and 0.6 bar) were used to determine the permeate flux and protein mass flow needed in the evaluation of the filtration efficiency. Compared to pasteurized cream, raw cream led to shorter filtration time. Pasteurization induced protein adsorption on the surface of fat globules, thus decreasing separation efficiency. Furthermore, pH was found to fluctuate during the diafiltration, owing to the decrease of buffering capacity by cream in the course of protein and mineral permeation and subsequent equilibration process of colloidal phosphates with serum phase. A relatively higher filtration pH increased filtration efficiency and protected fat globules from coalescence, given the increased osmotic pressure (electrostatic repulsion). Overall, the protein content in cream decreased by ~ 80% upon microfiltration. Despite the reduced protein concentration in the filtered creams, no negative effects were observed during churning into butter, which resulted in low-protein content buttermilk (~ 80% protein reduction). Hence, the ideal butter process can be used to facilitate MFGM isolation and better handling of process streams. [ABSTRACT FROM AUTHOR]

Chitosan (CS), cellulose nanofibrils (CNF) and boric acid, the latter of which was used as flame retardant, were combined in transparent, hybrid films that were produced by solvent casting. The flammability and the thermal stability of the films were studied with respect to the loading of the inorganic component. Chitosan films displayed fire retardancy properties, which were enhanced in the presence of boric acid. CNF films, in contrast to those from chitosan, were readily flammable; however, when combined with boric acid (30 w%), they became self-extinguishing. Most remarkably, bicomponent films comprising CNF and chitosan, displayed better fire retardancy than that of neat CS films. Moreover, boric acid improved the thermal stability of the bicomponent films. The tensile strength and Young’s modulus of CS, CNF and CS-CNF films improved at intermediate boric acid addition, although a negative effect on elongation was observed. [ABSTRACT FROM AUTHOR]

The development of new approaches for pesticide delivery is a most relevant subject in the area of crop protection, which typically involves relatively high pesticide dosing combined with low deposition and limited biosafety. Herein, we investigate a pesticide carrier system based on plant-derived, eco-friendly cellulose nanocrystals (CNCs) modified with β-cyclodextrin (β-CD) and tannic acid (TA). A broad-spectrum and widely used pesticide, fenitrothion (XCM), was shown to bind to the carrier through hydrophobic and hydrogen bonding interactions and Cu2+ coordination, enabling pH-controlled delivery. The high axial aspect of CNCs and surface features endowed by β-CD binding facilitated contact and enhanced the deposition efficiency on the foliage. The tannic acid further improved wetting, adhesion and retention on leaves (1.8-fold higher than TA-free systems). The bioactivity tests showed efficient antifungal (74%) and insecticidal (97%) effects along with excellent biosafety, highlighting the introduced carrier for its promise in the area of pesticide delivery. [ABSTRACT FROM AUTHOR]

There is an urgent need to develop materials to prevent bacterial infection and the deleterious effects of endotoxins. In this study, we introduce a one-step electrodeposition method to prepare films composed of chitosan/Ag/polypyrrole and layer-by-layer self-assembly to introduce lignin sulphonate (LS) to obtain chitosan/Ag/polypyrrole/LS films. Antibacterial effects against both E. coli and S. aureus are shown by bacterial growth profiles and observation of bacteriostatic zones. Meanwhile, the addition of self-assembled LS improved the antibacterial effect of the film. For E. coli , the inhibition zone diameter was 0.93 cm, while for S. aureus , the inhibition zone diameter was 0.72 cm. Rapid and efficient endotoxin adsorption effects were shown whereby the electrostatic interactions between chitosan and endotoxin molecules played a major role. After adsorption for 1 h, in initial concentration of 1 EU/mL endotoxin solution, the adsorption efficiency could reach up to 85 %, while in initial concentration of 5 EU/mL endotoxin solution, the adsorption efficiency could reach up to 87.6 %. The results suggest chitosan/Ag/polypyrrole/LS films for their capability as a new type of antibacterial film with intrinsic endotoxin adsorption activity. [ABSTRACT FROM AUTHOR]

[Display omitted] • Reported a cost-effective and scalable two-step method to produce SCALs under room fabrication conditions. • Methylation step prevents water-induced defects after treatment with organosilanes in room environment. • As-fabricated SCALs exhibited durability, anti-adhesion, transparency, and fouling/contaminant-resistance. Slippery lubricant-infused porous surfaces (SLIPs) are effective in repelling low-surface tension fluids given their omniphobicity, anti-adhesive, and drag reduction properties. However, over time, SLIPs are subjected to lubricant losses and undergo dust fouling. In this research, we address these challenges by developing a new slippery covalently attached liquids (SCAL) surface. SCALs was composed of a molecularly-thick lubricant layer covalently bound to the solid support, generating long-lasting anti-fouling, hydrophobic and slippery effects. We show that our SCALs exhibit ultra-low contact angle hysteresis for a wide range of fluids and enable reduced colloidal forces in the vertical and lateral directions (adhesion and friction, respectively). In parallel, the SCALs exhibit a high resistance to contamination (from molecular adhesion to dust fouling), mechanical integrity, and light transmission. Overall, we introduce a facile, cost-effective, and scalable process to synthesize a SCALs system suitable to the demands of application in bioengineering, power generation and water harvesting. [ABSTRACT FROM AUTHOR]

Ionic conductive gels are widely sought after for applications that require reliable ionic conduction and mechanical performance under extreme conditions, which remains a grand challenge. To address this limitation, water‐induced hydration interactions are deliberately controlled within the ionic liquid (IL)‐based conductive gels (ionogels) to achieve all‐round performance. Specifically, the competitive interactions between IL, water and cellulose nanofibrils (CNF) are balanced to preserve the nanoscale morphology of CNF while avoiding its dissolution. As a result, both mechanical performance and ionic conductivity of the resultant ionogel are synergistically enhanced. For instance, an ultra stretchable ionogel (up to 10250 ± 412% stretchability) with both high toughness (21.8 ± 0.9 MJ m−3) and ionic conductivity (0.70 ± 0.06 S m−1) is achieved. Furthermore, multimodal sensing functions (strain, compression, temperature, and humidity) are realized by assembling the ionogel as a skin‐like membrane. Due to the low volatility of IL and its strong interaction with water, the ionogel maintains an excellent performance at either ultra‐low temperature (−45 °C), high temperature (75 °C) or low humidity environment (RH < 15%), demonstrating superb anti‐freezing and anti‐drying performance. Overall, a simple yet versatile strategy is introduced that leads to environmentally resilient ionogels to meet the requirements of next‐generation electroactive devices. [ABSTRACT FROM AUTHOR]