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Water pollution caused by industrial discharges is a severe threat to our society. Thus, efficient and sustainable materials that can provide potential effective solutions are in high demand. The present work reports the development of a versatile strategy based on TEMPO-oxidized cellulose nanofibers (TOCN)/cationic guar gum (CGG) self-assembling hydrogels to remedy wastewater containing oil, heavy metal ions or organic dyes. The TOCN/CGG hydrogel-coated filter papers, prepared via a layer-by-layer deposition process, show a high oil/water separation efficiency (around 99%), with the coating amount of being as low as 0.032 g m−2 (dry mass). Through gravitational force only, the water flux can be as high as 443 L m−2 h−1. The as-prepared oil/water separation materials exhibited good recyclability. The monolithic TOCN/CGG hydrogel can also efficiently remove copper ions (Cu2+) and dyes (i.e. thioflavin T and methyl orange), based on an adsorption mechanism. The adsorption amount of Cu2+ can be as high as 498.5 mg g−1, while that of thioflavin T and methyl orange can be 430.2 mg g−1 and 134.3 mg g−1, respectively. The mass transfer driving force and the number of active binding sites are the two main factors affecting the adsorption process. This all-polysaccharide hydrogel system may be a promising potential for wastewater remedy, due to its facile/"green" preparation process and high performance, as well as the abundance and environmental-friendliness of its raw materials. [ABSTRACT FROM AUTHOR]

Based on the C 16mim PF 6 inducing microphase separation during the self-assembly of poly-benzoxazine, the skin-tissue-bone like hierarchical porous carbon with N, P co-doping was obtained, which shows a superior rate performance and a good specific capacitance. Introduction of hierarchical porous structure and heteroatom in porous carbons are always effective approaches to improve the capacitive performance for supercapacitor. However, it is still a challenge to achieve the desired structure characteristics by a convenient one-step synthesis. Herein, C 16 mimPF 6 , an ionic liquid, was introduced in the self-assembly process of poly-benzoxazine to obtain a unique skin-tissue-bone structured hierarchical porous carbon with homogeneous N, P co-doping after carbonization. As the key component, C 16 mimPF 6 works not only as a structure-directing agent to form a hierarchical structure through microphase separation mechanism, thereby promoting the transfer of ion and electron, but also as a heteroatom precursor to contribute an additional pseudocapacitance by doping phosphorus atoms on carbon matrix. The obtained porous carbon displays a high gravimetric capacitance (C g) of 209 F g−1 (especially in the carbons prepared without corrosive activation step), a good volumetric capacitance (C v) of 132 F cm−3 and an excellent area-normalized capacitance (C a) of 35 μF cm−2. Overall, this work opens a new way to design the polymer-derived carbons with easy heteroatoms doping and hierarchical porous structure. [ABSTRACT FROM AUTHOR]

We describe the novel mechanism of spontaneous formation of the concentric stripe patterns of microdiamonds via gradual solvent evaporation from a suspension confined in a teardrop well. The self-organized patterns exhibit a series of arcs with regular spacings varying between hundreds of micrometers and millimeters. They result from an interplay between the directional forced circulation of the solvent and a stick-slip movement of its contact line during the gradual drying of the suspension. We reveal the mechanism of the phenomenon and discuss the effects of various parameters on the obtained structures. [Display omitted] [ABSTRACT FROM AUTHOR]

In this work, amphiphilic hyaluronan was synthesized by grafting succinylated N -oleoyl-phytosphingosine via esters bonds. Succinylated N -oleoyl-phytosphingosine (sCER) was first prepared by esterification of hydroxyl moieties of the ceramide with succinic anhydride. The esterification of hyaluronan was governed by crowding effect. The oligomeric HA-sCER derivatives exhibited a strong self-aggregation as evidenced by a very low critical aggregation concentration (1.9 μg mL−1), higher pyrene binding constant (K B), and the smallest particle size (30 nm) in solution. The self-aggregation properties demonstrated to be a function of the substitution degree and molecular weight of HA. The prepared derivatives were non-cytotoxic towards cell lines NIH-3T3. Nanoparticles prepared using oligomeric HA-sCER derivatives improved the penetration of Nile red dye through the stratum corneum due to their smaller size (≤50 nm). The fluorescence intensity localized at the stratum corneum was higher for oligomeric HA-sCER. A significant inhibition of the pro-inflammatory cytokine interleukin-6 production was observed in vitro in macrophages differentiated from THP-1 cells. These findings showed that HA-sCER constituted a promising active ingredient for cosmetics use. [Display omitted] [ABSTRACT FROM AUTHOR]

Despite being a mainstay of clinical cancer treatment, chemotherapy is limited by its severe side effects and inherent or acquired drug resistance. Nanotechnology-based drug-delivery systems are widely expected to bring new hope for cancer therapy. These systems exploit the ability of nanomaterials to accumulate and deliver anticancer drugs at the tumor site via the enhanced permeability and retention effect. Here, we established a novel drug-delivery nanosystem based on amphiphilic peptide dendrimers (AmPDs) composed of a hydrophobic alkyl chain and a hydrophilic polylysine dendron with different generations (AmPD KK2 and AmPD KK2K4). These AmPDs assembled into nanoassemblies for efficient encapsulation of the anti-cancer drug doxorubicin (DOX). The AmPDs/DOX nanoformulations improved the intracellular uptake and accumulation of DOX in drug-resistant breast cancer cells and increased permeation in 3D multicellular tumor spheroids in comparison with free DOX. Thus, they exerted effective anticancer activity while circumventing drug resistance in 2D and 3D breast cancer models. Interestingly, AmPD KK2 bearing a smaller peptide dendron encapsulated DOX to form more stable nanoparticles than AmPD KK2K4 bearing a larger peptide dendron, resulting in better cellular uptake, penetration, and anti-proliferative activity. This may be because AmPD KK2 maintains a better balance between hydrophobicity and hydrophilicity to achieve optimal self-assembly, thereby facilitating more stable drug encapsulation and efficient drug release. Together, our study provides a promising perspective on the design of the safe and efficient cancer drug-delivery nanosystems based on the self-assembling amphiphilic peptide dendrimer.

Peptide-based hydrogels (PHGs) are biocompatible materials suitable for biological, biomedical, and biotechnological applications, such as drug delivery and diagnostic tools for imaging. Recently, a novel class of synthetic hydrogel-forming amphiphilic cationic peptides (referred to as series K), containing an aliphatic region and a Lys residue, was proposed as a scaffold for bioprinting applications. Here, we report the synthesis of six analogues of the series K, in which the acetyl group at the N-terminus is replaced by aromatic portions, such as the Fmoc protecting group or the Fmoc-FF hydrogelator. The tendency of all peptides to self-assemble and to gel in aqueous solution was investigated using a set of biophysical techniques. The structural characterization pointed out that only the Fmoc-derivatives of series K keep their capability to gel. Among them, Fmoc-K3 hydrogel, which is the more rigid one (G’ = 2526 Pa), acts as potential material for tissue engineering, fully supporting cell adhesion, survival, and duplication. These results describe a gelification process, allowed only by the correct balancing among aggregation forces within the peptide sequences (e.g., van der Waals, hydrogen bonding, and π–π stacking).

Extremely stable and biocompatible 3D magnetically responsive photonic crystals (MRPCs) are successfully prepared in aqueous solution. Classic hydrothermal synthesis was applied for preparation of the Fe3O4@C core. Modified Stöber method was then employed for synthesis of the different size of Fe3O4@C@SiO2. Unlike the traditional magnetic nanoparticles, the highly negative charged superparamagnetic nanospheres (SMNs), i.e., the double-shell structure Fe3O4@C@SiO2 are capable of rapidly self-assembling into 3D MRPCs with full visible and various colors that can be periodically and reversibly tuned under different kinds of external magnetic fields (EMFs) within 1 s. The assembling behavior and mechanism of the 3D MRPCs under EMF were monitored and analyzed. The preparation is simple and the size of the SMN is easily controllable by adjusting the amount of catalyst. Compared with the previous works, the synthesized 3D MRPCs are hydrophilic, and exhibit extremely high stability after 6-month storage. To conclude, our study provides an effective two-step strategy for fabrication of biocompatible 3D MRPCs and it reveals great potentials in biological fields.

Bioimaging is a powerful tool for diagnosing tumors but remains limited in terms of sensitivity and specificity. Nanotechnology-based imaging probes able to accommodate abundant imaging units with different imaging modalities are particularly promising for overcoming these limitations. In addition, the nanosized imaging agents can specifically increase the contrast of tumors by exploiting the enhanced permeability and retention effect. A proof-of-concept study is performed on pancreatic cancer to demonstrate the use of modular amphiphilic dendrimer-based nanoprobes for magnetic resonance (MR) imaging (MRI) or MR/near-infrared fluorescence (NIRF) multimodality imaging. Specifically, the self-assembly of an amphiphilic dendrimer bearing multiple Gd 3+ units at its terminals, generates a nanomicellar agent exhibiting favorable relaxivity for MRI with a good safety profile. MRI reveals an up to two-fold higher contrast enhancement in tumors than in normal muscle. Encapsulating the NIRF dye within the core of the nanoprobe yields an MR/NIRF bimodal imaging agent for tumor detection that is efficient both for MRI, at Gd 3+ concentrations 1/10 the standard clinical dose, and for NIRF imaging, allowing over two-fold stronger fluorescence intensities. These self-assembling dendrimer nanosystems thus constitute effective probes for MRI and MR/NIRF multimodality imaging, offering a promising nanotechnology platform for elaborating multimodality imaging probes in biomedical applications., (© 2023 The Authors. Advanced Materials published by Wiley-VCH GmbH.)

The self‐organization process of polysaccharide alginate with different cationic surfactants at the water‐air interface was investigated over a wide concentration regime. The changes of surface properties determined by surface tension measurements, surface rheology, and X‐ray reflectivity are correlated with changes of bulk properties measured by turbidity, light scattering, and zeta potential measurements. We demonstrate that the interactions between the alginate and cationic surfactants result in significant changes of bulk and interfacial properties. The results of surface shear experiments point to the existence of highly viscoelastic interfacial films. In combination with X‐ray reflectivity, we demonstrate that these rheological features are related to polymer‐surfactant associations at the interface. In the regime of high surfactant concentrations, we observed the existence of multilayer structures. [ABSTRACT FROM AUTHOR]

Current tissue-regenerative biomaterials confront two critical issues: the uncontrollable delivery capacity of vascular endothelial growth factor (VEGF) for adequate vascularization and the poor mechanical properties of the system for tissue regeneration. To overcome these two issues, a self-assembling in situ gel based on lyotropic liquid crystals (LLC) was developed. VEGF-LLC was administrated as a precursor solution that would self-assemble into an in situ gel with well-defined internal inverse bicontinuous cubic phases when exposed to physiological fluid at a defect site. The inverse cubic phase with a 3D bicontinuous water channel enabled a 7-day sustained release of VEGF. The release profile of VEGF-LLC was controlled using octyl glucoside (OG) as a hydration-modulating agent, which could enlarge the water channel, yielding a 2-fold increase in water channel size and a 7-fold increase in VEGF release. For the mechanical properties, the elastic modulus was found to decrease from ∼100 kPa to ∼1.2 kPa, which might be more favorable for angiogenesis. Furthermore, the self-recovery ability of the VEGF-LLC gel was confirmed by quick recovery of the inner network in step-strain measurements. In vitro , VEGF-LLC considerably promoted the proliferation, migration, and tube formation of human umbilical vein endothelial cells (HUVECs) as compared to free VEGF (p < 0.05). Furthermore, angiogenesis was successfully induced in rats after subcutaneous injection of VEGF-LLC. The self-assembling LLC gel showed satisfactory degradability and mild inflammatory response with little impact on the surrounding tissue. The controllable release profile and unique mechanical properties of VEGF-LLC offer a new approach for tissue regeneration. The potential clinical use of currently available biomaterials in tissue regeneration is limited by their uncontrollable drug delivery capacity and poor mechanical properties. Herein, a self-assembling in situ gel based on lyotropic liquid crystals (LLC) for induced angiogenesis was developed. The results showed that the addition of octyl glucoside (OG) could change the water channel size of LLC, which enabled the LLC system to release VEGF in a sustained manner and to possess a suitable modulus to favor angiogenesis simultaneously. Moreover, the self-recovery capability allowed the gel to match the deformation of surrounding tissues during body motion to maintain its properties and reduce discomfort. In vivo , angiogenesis was induced by VEGF-LLC 14 days after administering subcutaneous injection. These results highlight the potential of LLC as a promising sustained protein drug delivery system for vascular formation and tissue regeneration. [ABSTRACT FROM AUTHOR]

By the appropriate selection of functional peptides and proper accommodation sites, we have generated a set of multifunctional proteins that combine selectivity for CXCR4+ cell binding and relevant endosomal escape capabilities linked to the viral peptide HA2. In particular, the construct T22-GFP-HA2-H6 forms nanoparticles that upon administration in mouse models of human, CXCR4+ colorectal cancer, accumulates in primary tumor at levels significantly higher than the parental T22-GFP-H6 HA2-lacking version. The in vivo application of a CXCR4 antagonist has confirmed the prevalence of the CXCR4+ tumor tissue selectivity over unspecific cell penetration, upon systemic administration of the material. Such specificity is combined with improved endosomal escape, what overall results in a precise and highly efficient tumor biodistribution. These data strongly support the functional recruitment as a convenient approach to generate protein materials for clinical applications. More precisely, they also support the unexpected concept that enhancing the unspecific membrane activity of a protein material does not necessarily compromise, but it can even improve, the selective cell targeting offered by an accompanying functional module. We have shown here that the combination of cell-penetrating and tumor cell-targeting peptides dramatically enhances precise tumor accumulation of protein-only nanoparticles intended for selective drug delivery, in mouse models of human colorectal cancer. This fact is a step forward for the rational design of multifunctional protein nanomaterials for improved cancer therapies. [ABSTRACT FROM AUTHOR]

• Self-assembling guar gum hydrogel-coated cotton fabric for oil/water separation. • High separation efficiency under alkaline and salty environments. • Good recyclability of the filtering material. "Green" and cost-effective materials for oil/water separation are in high demand to address worldwide water pollution issues. Herein we report a guar gum (GG)-based self-assembling hydrogel for oil/water separation. A cotton fabric was first coated with GG solution, followed by immersion in a sodium periodate (NaIO 4) solution. The GG gelation was induced by regioselective oxidation with NaIO 4. The in-situ formed aldehydes react with hydroxyl groups in the GG polymer chains, leading to the formation of acetals that crosslink the GG chains. The resultant GG hydrogel-coated cotton fabric was demonstrated to be capable of selectively separating different oily wastewaters, with separation efficiency of 98.11%, 97.53% and 99.47% for silicone oil, canola oil and cyclohexane, respectively. Due to the excellent antifouling properties and reasonable strength of the GG hydrogel, as well as its good affinity with cotton fabric, the as-prepared filtering material possesses high separation efficiency after 10 times of reuse. Moreover, it maintains good oil/water separation capability in alkaline and salty environment. [ABSTRACT FROM AUTHOR]

The study presents the effect of adding p-tert-butylcalix[4]arene, benzo ether crowns and their equimolecular mixture in the organic phase on the interfacial tension for the chloroform water interface. It was found that addition of macrocyclic ligands to the organic phase has different effects on the interfacial tension. The higher the number of oxygen atoms in the ethereal ring of the benzo crown ethers, the higher the values of interfacial tension, while same modification of the ethereal ring produces an opposite effect in the case of amino benzo ethers, indicating different arrangements of molecules in the interface. The simultaneous presence of p-tert-butylcalix[4]arene and benzo crown ethers in the interface leads, in some situations, to significant changes in the interfacial tension values, a phenomenon explained by the modification of the macrocyclic ligands assembly in the interface. Also, composition of the aqueous phase influences the value of measured interfacial tension, type of the alkaline cation from the aqueous solution leading to different behavior of macrocyclic ligands in the interface. [ABSTRACT FROM AUTHOR]

Biomedical/pharmaceutical applications demand hydrogels made from biobased materials without the use of potentially toxic or denaturizing crosslinking agents. In this work, a new all-polysaccharide self-assembling hydrogel system consisting of anionic TEMPO-oxidized cellulose nanofibers (TOCNs) and cationic guar gum (CGG) is proposed. The TOCNs/CGG hydrogel are formed in situ when TOCNs and CGG are mixed, due to the electrostatic interactions and abundant hydrogen bondings therein. Interactions in the hydrogel were supported by Fourier transform infrared spectroscopy (FTIR) results. The as-prepared hydrogel showed good injectability, self-healing performance and reasonable mechanical properties. Scanning electron microscope (SEM) images illustrated the network structure of the hydrogel. Furthermore, the TOCNs/CGG hydrogel system was studied for protein drug release, in which bovine serum albumin (BSA) was used as a model drug to examine the drug release performance in buffers at pH 2.0 or 7.4, simulating gastrointestinal tract conditions. The results indicate its sustained drug releasing ability. A mathematical analysis of the release results supports an anomalous transport mechanism for the TOCNs/CGG hydrogel system. [ABSTRACT FROM AUTHOR]

The judicious combination of shaping and recognition elements in cage-type architectures represents a powerful strategy to access molecular devices with tailored receptor properties and controlled abilities to form supramolecular assemblies. Aromatic modules are particularly attractive for these endeavors: they can play the role of rigid walls to build permanent cavities, folding screens between preexisting compartments and/or act as functional components promoting noncovalent self-interactions as well as associations with third species, allowing several levels of organization to be implemented. The field of cyclodextrins has enormously benefitted from the amalgamation with aromatic building blocks to give birth to hybrids with a much broader spectrum of properties and applications. The progress in precision chemistry has further enabled the efficient preparation of multiply-linked cap, hinge or clip cyclodextrin-aromatic chimeras with unprecedented level of control, which has translated into new developments in fields like supramolecular catalysis, self-assembly or gene delivery. This review article focuses specifically in these type of compounds, highlighting the intimate relationship between structure, supramolecular properties and performance in the target application. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Switchable systems, based on porphyrins, phthalocyanines and related macrocycles. • Various types of an input signals to trigger the tetrapyrrolic switches. • Various types of output signals which might be obtained from tetrapyrrolic switches. • Applications of tetrapyrrole switches in elaboration of smart materials. Abstract Porphyrins and phthalocyanines are well-known colourful compounds, which attract much attention in various fields of science and technology, including the area of molecular switches and machines – an emerging multidisciplinary area, which is expected to provide novel classes of materials for data storage and processing, smart materials with switchable properties, etc. This review is aimed to exemplify various types of switchable systems, based on porphyrins, phthalocyanines and related macrocycles to give the link between the physical-chemical properties of the parent macrocycles, different types of input signals and mechanisms of responses, leading to detectable outputs. Specifically, attention will be paid to switching of properties which are meaningful for practical applications of porphyrinoids – change of optical characteristics, alteration of excited state dynamics, switching between different spin states and tuning of magnetic properties. [ABSTRACT FROM AUTHOR]

Abstract 1,3-divinyltetramethyldisiloxane (V2), 1,3,5-trivinyl-1,3,5-trimethylcyclotrisiloxane (V3), and 1,3,5,7-tetravinyl-1,3,5,7-tetramethylcyclotetrasiloxane (V4) are used as hydrophobic substrates to attach carboxyl groups by thermal or photochemical activated thiol-ene addition of 3-mercaptopropionic acid (R1), thioglycolic acid (R2) and thioacetic acid (R3). The reactions occurrence is monitored by IR following the disappearance of specific absorption bands for -S-H and –CH=CH 2 bonds. At the end, the structure of the compounds and thioetherification degree of vinyl groups are determined by NMR. Co-existence in the structure of the highly hydrophobic methyl group and the carboxyl or carbonyl group gives the compounds formed an amphiphilic character, as indicated by the calculated hydrophilic-lipophilic balance, making them capable of self-assembling in solution, as the results of the dynamic light scattering (DLS) and nanoparticle tracking analysis (NTA) measurements also show. Under normal temperature conditions, these compounds are in the liquid state. The DSC measurements in the range (−150) – (+150) reveal only a glass transition in the negative field and no other thermal transitions or decomposition processes. This behavior could make these compounds containing polar groups useful as solvent-free liquid electrolytes. Dielectric spectra reveal an increase in both dielectric permittivity and conductivity of the thiol-ene addition products as compared with starting vinyl-siloxanes. The increase is even more significant after doping with lithium salt, reaching conductivity values of order 10−4 S/cm. Highlights • Methylvinylsiloxanes are functionalized with carboxyl groups by thiol-ene addition. • The compounds are in a liquid state in a wide temperature window. • Amphiphilic nature is proved by theoretical calculations and experimental measurements. • In solution, the compounds self-assemble to form aggregates proved by video images. • Compounds exhibit conductivities up to 10−4 S/cm when are in Li-doped form. [ABSTRACT FROM AUTHOR]

Abstract Here we report a new and straightforward method to yield durable polyelectrolyte complexes (hydrogel PECs) from gellan gum (GG) and chitosan (CS) assemblies, without metallic and covalent crosslinking agents, commonly used to produce GG and CS-based hydrogels, respectively. This new approach overcomes challenges of obtaining stable and durable GG-based hydrogels with structural homogeneity, avoiding precipitation and aqueous instability, typical of PEC-based materials. PECs are created by blending CS:GG solutions (at 60 °C) with GG:CS weight ratios between 80:20 to 40:60. X-ray photoelectron spectroscopy (XPS) analysis shows that CS-GG chains are interacting by electrostatic and intermolecular forces, conferring a high degree of association to the washed PECs, characteristic of self-assembling of polymer chains. The CS:GG weight ratio can be tuned to improve polyelectrolyte complex (PEC) high porosity, stability, porous homogeneity, and degradation rate. Physical and thermosensitive CS/GG-based hydrogels can have advantages over conventional materials produced by chemical processes. Highlights • Chitosan/gellan gum polyelectrolyte complexes were prepared. • Chitosan:gellan gum weight ratio plays a significant role in the features of the materials. • The materials present stability, self-assembling, structural homogeneity and slow degradation rate. [ABSTRACT FROM AUTHOR]

Abstract Novel nanostructured three-dimensional flowerlike Mg(OH) 2 -incorporated granular polyurethane (designated as gPU-FMH) was prepared using a simple hydrothermal method, for which commercial MgO, water, and granular polyurethane (gPU) were applied. Interestingly, it is found that gPU and the hydrothermal process are the key factors for the assembly of the flowerlike structures of the Mg(OH) 2 , as its hexagonal nanosheet petals provide a high surface area. Temperature significantly controlled the morphologies of the flowerlike Mg(OH) 2 , and the granular gPU-FMH showed the superb adsorption capacities of 472, 1050, and 1293 mg g−1 (maximum adsorption capacities, q m , from Langmuir model) for Cu(II), Cd(II), and Pb(II), respectively. The proposed hypothesis for the synthesis of gPU-FMH and the removal mechanism of the heavy metals has been proved through various spectroscopic analyses. In the result of the continuous-flow column study, gPU-FMH showed a long breakthrough and a high removal capacity (184 mg g−1) of Cu(II). Graphical abstract Image 1 Highlights • Nanostructured 3D flowerlike Mg(OH) 2 coated PU (PU-FMH) was synthesized. • PU-FMH can be synthesized only by commercial MgO, water, and PU. • PU and hydrothermal process are the key factors for the assembly of PU-FMH. • PU-FMH showed the superb adsorption capacities of various heavy metals. • PU-FMH have a much higher removal capacity of cupper than other media. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • An evaporation-induced self-assembly method was used to obtain FePc coated AC. • Loading of FePc on AC influenced the properties of Fe-N/AC. • Fe-N/AC could catalyze ORR via indirect 4e- pathway with high efficiency. • MFC using Fe–N/AC as cathode showed comparable performance to that using Pt/C. • Fe–N/AC will be promising alternative cathode catalyst of MFCs in the future. Abstract To improve the power generation of microbial fuel cells (MFCs), iron–nitrogen/activated carbon (Fe–N/AC), an excellent oxygen reduction reaction (ORR) electrocatalyst, was prepared by pyrolyzing iron(II) phthalocyanine (FePc)-coated AC, which was formed via an evaporation-induced self-assembly method. Given the high content of nitrogen and iron elements, crystalline structure, high surface area, and appropriate composition of micropores and mesopores, Fe–N/AC synthesized with 50.0 wt% of FePc loading on AC exhibits enhanced ORR electrocatalytic activity. The Fe–N/AC can catalyze ORR via an indirect four-electron pathway in neutral medium with onset potential of 0.883 V versus reversible hydrogen electrode and electron transfer number of 3.91. In comparison with AC, the charge transfer resistance and exchange current density of Fe–N/AC decreases by 62% and increases by a factor of three, respectively. The maximum power density of MFC using Fe–N/AC reaches 1092 mW m−2, which is 63.23% higher than that of AC and equal to that of Pt/C. This study proposes a new approach for the design of alternative non-precious metal ORR electrocatalysts in neutral pH medium, which may have potential application in practical MFCs as cathode catalysts in the future. [ABSTRACT FROM AUTHOR]

The synthetic strategy for iron oxides with diverse superstructures has become one of the most promising researches due to their advance and synergistic application in energy and environment field. Self-assembling of nanostructure to structural hierarchy in general enhances mass transportation, reducing resistance to diffusion, and high surface areas for adsorption and electrochemical reaction, and thus much effort has been devoted to the exploration of various novel synthesis schemes for high-throughput synthesis processes with a choice of starting materials. In this strategy, we utilize metal-organic solvent solutions as the starting material for synthesizing functional hierarchical iron oxide materials without further addition of base for hydrolysis reactions. The process is templates/surfactant less which makes the process simple without intact of other impurities in desired structure. The agglomerations of the particles are also controlled due to acidic pH condition adopted during synthesis. All the experiments were done at a moderate temperature (~ < 100 °C) with a variation of time and concentration. The reaction parameters are optimized to get uniform and highly dispersed flower or spindle-shaped 3D hierarchical goethite phase and thereof we evaluate the electrochemical capacitance using cyclic voltammetry technique. One of the pure iron oxide samples shows specific capacitance value of 243.2 Fg−1 and exhibited 26 Wh Kg−1 energy density at 0.5 Ag−1 current density. [ABSTRACT FROM AUTHOR]

Abstract Nanocomposites based on block copolymer (BCP) and gold nanoparticles (NPs) filler were measured in terms of their structure and polymer chain molecular dynamics. NPs were functionalized in order to gain selective affinity to one specific type of BCP domain. BCP directed NPs assembly was monitored using atomic force microscopy. Thin nanocomposite films were fabricated via spin-coating technique, annealed and subsequently subjected to reactive ion etching in order to expose inorganic NPs location within the BCP matrix. Selective NPs incorporation was confirmed. Furthermore, interesting NPs distribution in quasi-2D crystallites was revealed. Spectroscopic methods (nuclear magnetic resonance and dielectric spectroscopy) enabled investigation of polymer chain reorientations and estimation of the impact of nano-filler on polymer dynamics. Nanocomposite crystallinity was assessed via thermal analysis and supported by spectroscopic techniques. Graphical abstract Image 1 Highlights • BCPs based nanocomposites domain structure was studied using AFM. • BCPs based nanocomposites polymer dynamics was studied using dielectric spectroscopy and NMR. • Selective NPs incorporation into BCPs domains was confirmed. [ABSTRACT FROM AUTHOR]

Liquid crystalline (LC) diblock copolymers containing a side-on LC block and a pseudo-stilbene azobenzene block were synthesized, and their self-assembling in water/tetrahydrofuran (THF) was investigated. Side-on LC monomer 4"-methylacryloyloxybutyl 2,5-di(4'-butyloxybenzoyloxy) benzoate (4-MDBB) was synthesized, and then polymerized into P4MDBB through reversible addition-fragmentation chain transfer (RAFT) polymerization. A pseudo-stilbene azobenzene monomer 6-(N-methyl-N-(4-(4'-cyanophenylazo)phenyl)amino)hexyl methacrylate (6-NCN) was also synthesized. The diblock copolymers P4MDBBm-b-P6NCNn were obtained through the RAFT polymerization of 6-NCN by using P4MDBB as the chain transfer agent. The copolymers and the intermediates were confirmed by 1H and 13C NMR spectra, FT-IR spectra, UV-Vis spectra, mass spectra, DSC analysis, POM observations, GPC tests and contact angle measurements. The diblock copolymers self-assembled upon adding water slowly into their THF solutions. The self-assembling and the corresponding assemblies were characterized by fluorescence spectra, laser light scattering experiments as well as TEM measurements. Results demonstrated that these diblock copolymers form spherical aggregates in water/THF, but the aggregates are un-stretchable upon irradiation with polarized light. [ABSTRACT FROM AUTHOR]

Background: In recent years, multifunctional theranostic nanoparticles have been fabricated by integrating imaging and therapeutic moieties into one single nano-formulations. However, Complexity of production and safety issues limits their further application. Results: Herein, we demonstrated self-assembled nanoparticles with single structure as a "from one to all" theranostic platform for tumor-targeted dual-modal imaging and programmed photoactive therapy (PPAT). The nanoparticles were successfully developed through self-assembling of hyaluronic acid (HA)-cystamine-cholesterol (HSC) conjugate, in which IR780 was simultaneously incorporated (HSCI NPs). Due to the proper hydrodynamic size and intrinsic targeting ability of HA, the HSCI NPs could accumulate at the tumor site effectively after systemic administration. In the presence of incorporated IR780, in vivo biodistribution and accumulation behaviors of HSCI NPs could be monitored by photoacoustic imaging. After cellular uptake, the HSCI NPs would disintegrate resulting from cystamine reacting with over-expressed GSH. The released IR780 would induce fluorescence "turn-on" conversion, which could be used to image tumor sites effectively. Upon treatment with 808 nm laser irradiation, PPAT could be achieved in which generated reactive oxygen species (ROS) would produce photodynamic therapy (PDT), and subsequently the raised temperature would be beneficial to tumor photothermal therapy (PTT). Conclusion: The self-assembled HSCI NPs could act as "from one to all" theranostic platform for high treatment efficiency via PPAT pattern, which could also real-time monitor NPs accumulation by targeted and dual-modal imaging in a non-invasive way. [ABSTRACT FROM AUTHOR]

Graphical abstract Hydrophobic fluorinated cross-linked network films were prepared by self-assembling random fluoroacrylate polyol polymer on the HDI modified LB-SiO 2 particulate monolayers. Surface analyses show a low surface segregation degree of fluorinated groups. Highlights • The ester groups stretch towards the inner surface during film forming process. • The surface enrichment of fluorinated groups bonded to ester groups is difficult. • The surface hydrophobicity is attributed to the polymer main chain of -C-C-. Abstract Hydrophobic fluorinated particulate films were fabricated by coupling Langmuir-Blodgett silica (LB-SiO 2) particulate monolayers with fluoroacrylate polymer, and the depth distributions of chemical compositions were studied. The resultant fluorinated particulate films show surface hydrophobic property with water contact angles (WCA) of 123° (300 nm) and 125° (550 nm), which is dominated in Wenzel wetting state. The surface F/C ratio is only 0.09 at 20°, which is slightly higher than 0.07 at 60°. Fitting results of C1s and O1s high-resolution spectra at 20° and 60° indicate the outmost surface is mainly occupied by fluoroacrylate polymer main chains and the ester side chains stretch toward inner surface and thus hydrophobic fluorinated groups in self-assembled fluoroacrylate film cannot efficiently segregate to the outer surface, which results in low surface F/C ratio and surface WCA. [ABSTRACT FROM AUTHOR]

It was shown experimentally that the action of continuous electric field on nanoporous silicate glasses with interconnecting pores, containing silver nanoparticles, leads to the spatial redistribution of nanoparticles. The concentration of nanoparticles near the negative electrode increases and results in silver nano- and microdendrite structure growth. The main mechanisms of the described effects are the field emission of silver ions from silver nanoparticles near negative electrode, migration of silver ions in the external electric field to the negative electrode, reduction of silver ions by free electrons, and new silver nanoparticle formation. The experiments have shown that at the ends of microdendrites, local field enhancement appears, which results in luminescence enhancement and in SERS. [ABSTRACT FROM AUTHOR]

Long (15 - 40 μm), thin (diameter of 20 ± 5 nm), and well-dispersed CuNWs Cu nanowires were prepared. The high-resolution TEM and selected area electron diffraction showed that the CuNWs were single-crystalline. To investigate the growth mechanism, we examined the microstructure of these CuNWs at different reaction time. It was found that the CuNWs were actually formed through the self-assembling of Cu nanoparticles along the [110] direction. The transparent electrodes fabricated using the CuNWs achieved a high transparency of 76 % at 31±5 Ω/□. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Structure and color-transition behavior of 3 polydiacetylenes(PDAs) are explored. • Incorporation of aromatic head group yields reversible thermochromism. • The increase of head group size affects morphologies and packing structure of PDA. • Size of aromatic head group affects the color reversibility in high temperature region. • Sensitivity of the PDA to chemical stimuli varies with size of aromatic head group. Abstract This contribution investigates the morphologies, packing structure and color-transition behaviors of polydiacetylene(PDA) assemblies prepared from 10,12-pentacosadiynoic acid (PCDA), 3-(pentacosa-10,12-diynamido)benzoic acid (PCDA-mBzA), and 6-(pentacosa-10,12-diynamido)-2-naphthoic acid (PCDA-NPA). This series of PDAs provides a systematic increase of head group size and overall inter- and intramolecular interactions within the assemblies. The increase of head group size affects the packing parameter of diacetylene(DA) monomers, causing morphological change from spherical vesicles to rod-like structures. X-ray diffraction reveals that the size of the head group also dictates molecular tilting angle within the lamellar structure of DA assemblies. The monocarboxylic poly(PCDA) exhibits irreversible thermochromism. The incorporation of aromatic head groups in poly(PCDA-mBzA) and poly(PCDA-NPA) enhances the overall interactions within assemblies, resulting in reversible thermochromism. Furthermore, the size of aromatic head groups strongly affects the response time and color reversibility in thin film. Interestingly, the sensitivity of PDAs to chemical stimuli including cationic surfactants and organic solvents is found to vary with type of head group. The poly(PCDA-mBzA) is more sensitive to cationic surfactants compared to the system of poly(PCDA-NPA). An opposite result is observed when organic solvents, tetrahydrofuran and pyridine, are used as chemical stimuli. Our study provides fundamental understanding about molecular factors affecting the self-assembling structure and color-transition behaviors of PDA materials. [ABSTRACT FROM AUTHOR]

Abstract The paper discusses the viscometric behaviour of aqueous solutions of polyurethane (PU), poly(vinyl alcohol) (PVA), and their mixtures of different compositions at 37 °C. Two models were used to determine the intrinsic viscosity and viscometric interaction parameters: the classical Huggins equation and the new Wolf approach. The higher hydrodynamic volume of PVA/PU mixtures as compared with the individual macromolecules can be explained by the new thermodynamic approache. The viscometric data were used to evaluate different miscibility parameters which are discussed as a function of PVA/PU mixture composition. The different types of interactions occurring in solution contribute to the miscibility of the two polymers and the preferential PVA-PU intermolecular interactions are responsible for the self-assembling phenomena. The thermodynamic conditions are favorable for the formation of the mixed coils containing PVA macromolecules and PU micelles. Graphical abstract Unlabelled Image Highlights • Viscosity of polyurethane (PU), poly(vinyl alcohol) (PVA), and their mixtures in aqueous solutions was determined at 37 °C. • Intermolecular interactions contribute to the good miscibility of PVA and PU in aqueous solution. • The mixed coils are formed by interactions of PVA macromolecules and PU micelles. [ABSTRACT FROM AUTHOR]

The donor-acceptor character of diazatruxenones confers them an inherent dipole moment whose magnitude and directionality can be manipulated by appropriate functionalization. By maximizing the strength of this dipole, it is possible to induce columnar mesomorphism in this discotic platform with just two flexible alkyl chains, presumably driven by the antiparallel dipole-dipole arrangement of neighbouring molecules within the columns. [Display omitted] • Peripheral substitution significantly affects the self-assembling properties of diazatruxenones. • Functionalization influences the magnitude and directionality of the dipole moment inherent in diazatruxenones. • Peripheral electron-withdrawing groups induce mesomorphism in diazatruxenones through dipole–dipole interactions. • The antiparallel arrangement of dipoles in neighbouring diazatruxenones favors SCLC-determined hole transport. In this paper we present two sets of diazatruxenones functionalized at the 3,8 or 2,7 positions with two phenyl rings substituted at the para positions with groups of different electronic nature. With the aim to shed light on the role of the positional isomeric effect and of the electronic nature of the attached peripheral substituents on the final properties of these systems, we have performed a joint experimental and theoretical investigation linking thermal analysis, UV–Vis spectroscopy, electrochemistry and SCLC measurements with DFT calculations. The donor–acceptor character of these molecules not only confers them an interesting amphoteric redox behaviour but also creates a significant in-plane dipole moment. We have found that the different functionalization has only a slight impact on the electronic properties of these systems but exerts a significant influence on the strength and directionality of their dipole moment with strong implications in their self-assembly. Particularly, derivatives functionalized with electron acceptors, present the highest dipole moments within the series and form stable columnar mesophases, probably driven by the antiparallel dipole–dipole arrangement of neighbouring molecules. DFT calculations confirms that cofacially stacked dimers with their dipoles opposed allow for efficient electronic couplings helping to rationalize the favourable hole mobilities determined for the 3,8-disubstituted diazatruxenones with electron-acceptor groups by means of the space charge–limited current technique. [ABSTRACT FROM AUTHOR]

[Display omitted] • ZnTPP-CoTPP monolayers grown as compact wetting layers on Fe(0 0 1)- p (1 × 1)O. • ZnTPP-CoTPP monolayers on Fe(0 0 1)- p (1 × 1)O showed ordered surface reconstructions. • Sub-monolayer pre-coverage of CoTPP triggers molecular assembling switch in ZnTPP. • CoTPP dominates molecular assembling in co-deposited ZnTPP-CoTPP monolayers. • Central metal ion in porphyrins influences orientations in self-assembling. Metal tetraphenylporphyrins (MTPPs, with M = Zn, Co) deposited on an oxygen-passivated Fe substrate, namely Fe(0 0 1)- p (1 × 1)O, were studied to understand the mechanism of molecular self-assembling on ultrathin metal-oxide films. These were characterized by photoemission spectroscopy (PES) and low energy electron diffraction (LEED). Heterogeneous MTPP monolayers (ZnTPP + CoTPP) were grown at room temperature by depositing a sub-monolayer of ZnTPP on Fe(0 0 1)- p (1 × 1)O followed by a sub-monolayer of CoTPP or vice-versa, or by co-deposition. Homogeneous layers are characterized by markedly different molecular superstructures, as shown by LEED. Conversely, heterogeneous monolayers reflected an even more complex behavior: in particular, it was observed that the deposition of a small amount of CoTPP before or simultaneous to the dosing of ZnTPP molecules was able to stabilize a (5 × 5)R37° diffraction pattern, characteristic of homogeneous CoTPP, whereas homogeneous ZnTPP layers are associated to a straight (5 × 5) one. The observed differences in the ordering of the molecular self-assembling as a consequence of combining the two MTPPs highlights a significant influence of one MTPP over the other depending upon the central metal ion and not upon the molecular skeleton. [ABSTRACT FROM AUTHOR]

Photo-electrochemical and photocatalytic technologies are promising solutions for solar fuel production and involve a number of physical and chemical phenomena. We provide an overview of numerical and analytical tools to describe such phenomena occurring at disparate time and space scales within devices such as photo-electrochemical cells and photo-chemical reactors. On one hand, chemical phenomena include photo-induced electron transfer, charge separation, recombination, equilibrium reactions between species in solutions and adsorption reactions. On the other hand, examples of physical phenomena are the transport of chemical species or self-assembling of molecular structures. In this respect, we critically review macroscale continuum models for transport phenomena combined with kinetic descriptions including their possible coupling with models at even lower scales. We specifically focus on atomistic and coarse-grained models able to represent the local environment of the reactive interfaces such as photoelectrodes or supra-molecular assemblies. The critical role of the latter structures on photochemical conversion is highlighted: Therefore, morphological structure of self-assemblies, such as micelles and monolayers, in solution and at the solid–liquid or gas–liquid interfaces are also discussed. Finally, important scientific gaps are identified and possible perspectives for future research outlooked. [Display omitted] • Continuum and kinetic models for the description of photocatalytic processes. • Effect of the nanoscale phenomena on the photocatalytic performance at the macroscale. • Coupling coarse-grained and continuum models to investigate the reactive interfaces. [ABSTRACT FROM AUTHOR]

Amphiphilic dendrons represent a relatively novel class of molecules which may show many unique properties suitable for applications in a field of molecular biology and nanomedicine. They were frequently studied as platforms suitable for drug delivery systems as were, e.g. polymersomes or hybrid lipid-polymer nanoparticles. Recently, natural extracellular lipid vesicles (EVs), called exosomes (EXs), were shown to be a promising candidate in drug delivery applications. Formation of hybrid exosome-dendron nanovesicles could bring benefits in their simple conjugation with selective targeting moieties. Unfortunately, the complex architecture of biological membranes, EXs included, makes obstacles in elucidating the important parameters and mechanisms of interaction with the artificial amphiphilic structures. The aim of the presented work was to study the interaction of two types of amphiphilic carbosilane dendritic structures (denoted as DDN-1 and DDN-2) suitable for further modification with streptavidin (DDN-1) or using click-chemistry approach (DDN-2), with selected neutral and negatively charged lipid model membranes, partially mimicking the basic properties of natural EXs biomembranes. To meet the goal, a number of biophysical methods were used for determination of the degree and mechanisms of the interaction. The results showed that the strength of interactions of amphiphilic dendrons with liposomes was related with surface charge of liposomes. Several steps of interactions were disclosed. The initialization step was mainly coupled with amphiphilic dendrons - liposomes surface interaction resulting in destabilization of large self-assembled amphiphilic dendrons structures. Such destabilization was more significant with liposomes of higher negative charge. With increasing concentration of amphiphilic dendrons in a solution the interactions were taking place also in the hydrophobic part of bilayer. Further increase of nanoparticle concentration resulted in a gradual dendritic cluster formation in a lipid bilayer structure. Due to high affinity of amphiphilic dendrons to model lipid bilayers the conclusion can be drawn that they represent promising platforms also for decoration of exosomes or other kinds of natural lipid vehicles. Such organized hybrid dendron-lipid biomembranes may be advantageous for their subsequent post-functionalization with small molecules, large biomacromolecules or polymers suitable for targeted drug-delivery or theranostic applications. [Display omitted] • The strength of interactions was related to the surface charge of liposomes. • Several levels in a mechanism of amphiphilic dendrons (AD) and liposomes interactions. • Destabilization of AD aggregates more significant for negatively charged liposomes. • Incorporation of AD into the lipid bilayers structure. • High AD concentration resulted in a cluster formation in a lipid bilayer structure. [ABSTRACT FROM AUTHOR]

Yumin Zhang,1,* Junhui Zhou,2,* Cuihong Yang,1 Weiwei Wang,3 Liping Chu,1 Fan Huang,1 Qiang Liu,1 Liandong Deng,2 Deling Kong,3 Jianfeng Liu,1 Jinjian Liu1 1Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Science and Peking Union Medical College, 2Department of Polymer Science and Technology, School of Chemical Engineering and Technology, Tianjin University, 3Tianjin Key Laboratory of Biomaterial Research, Institute of Biomedical Engineering, Chinese Academy of Medical Science and Peking Union Medical College, Tianjin, People’s Republic of China *These authors contributed equally in this work Abstract: Although the shortcomings of small molecular antitumor drugs were efficiently improved by being entrapped into nanosized vehicles, premature drug release and insufficient tumor targeting demand innovative approaches that boost the stability and tumor responsiveness of drug-loaded nanocarriers. Here, we show the use of the core cross-linking method to generate a micelle with enhanced drug encapsulation ability and sensitivity of drug release in tumor. This kind of micelle could increase curcumin (Cur) delivery to HeLa cells in vitro and improve tumor accumulation in vivo. We designed and synthesized the core cross-linked micelle (CCM) with polyethylene glycol and folic acid-polyethylene glycol as the hydrophilic units, pyridyldisulfide as the cross-linkable and hydrophobic unit, and disulfide bond as the cross-linker. CCM showed spherical shape with a diameter of 91.2 nm by the characterization of dynamic light scattering and transmission electron microscope. Attributed to the core cross-linking, drug-loaded CCM displayed higher Nile Red or Cur-encapsulated stability and better sensitivity to glutathione than noncross-linked micelle (NCM). Cellular uptake and in vitro antitumor studies proved the enhanced endocytosis and better cytotoxicity of CCM-Cur against HeLa cells, which had a high level of glutathione. Meanwhile, the folate receptor-mediated drug delivery (FA-CCM-Cur) further enhanced the endocytosis and cytotoxicity. Ex vivo imaging studies showed that CCM-Cur and FA-CCM-Cur possessed higher tumor accumulation until 24 hours after injection. Concretely, FA-CCM-Cur exhibited the highest tumor accumulation with 1.7-fold of noncross-linked micelle Cur and 2.8-fold of free Cur. By combining cross-linking of the core with active tumor targeting of FA, we demonstrated a new and effective way to design nanocarriers for enhanced drug encapsulation, smart tumor responsiveness, and elevated tumor accumulation. Keywords: core cross-linking, folic acid targeting, self-assembling, curcumin, drug delivery, micelles

Nanoscale magnetic materials are the basis of emerging technologies to develop novel magnetoelectronic devices. Self-assembly of polystyrene nanospheres is here used to generate 2D hexagonal dot arrays on Fe50Pd50 thin films. This simple technique allows a wide-area patterning of a magnetic thin film. The role of disorder on functional magnetic properties with respect to conventional lithographic techniques is studied. Structural and magnetic characteristics have been investigated in arrays having different geometry (i.e. dot diameters, inter-dot distances and thickness). The interplay among microstructure and magnetization reversal is discussed. Magnetic measurements reveal a vortex domain configuration in all as-prepared films. The original domain structure changes drastically upon thermal annealing performed to promote the transformation of disordered A1 phase into the ordered, tetragonal L10 phase. First-order reversal magnetization curves have been measured to rule out the role of magnetic interaction among crystalline phases characterized by different magnetic coercivity.