Search

Ionic liquid lignins are prepared from sodium lignosulfonate by a cation exchange reaction and display glass transition temperatures as low as −13 °C. Diethyleneglycol‐functionalized protic cations inhibit lignin aggregation to produce a free‐flowing “ionic liquid lignin”, despite it being a high‐molecular‐weight polyelectrolyte. Through this approach, the properties of both lignin and ionic liquids are combined to create a dispersant and binder for cellulose+gluten mixtures to produce small microphases. Biocomposite testing pieces are produced by hot‐pressing this mixture, yielding a material with fewer defects and improved toughness in comparison to other lignins. The use of unmodified lignosulfonate, acetylated lignosulfonate, or free ionic liquid for similar materials production yields poorer substances because of their inability to maximize interfacial contact and complexation with cellulose and proteins., Hot off the press: Lignosulfonate is functionalized to create an ionic liquid with a glass transition temperature (T g) of −13 °C. After mixing with cellulose+gluten and hot‐pressing, composite materials are produced and have fewer defects and improved toughness in comparison to other lignins.

Hydrogels constitute an important class of polymeric materials, mainly due to their promising applications in the biomedical field. Particularly, mechanical properties are a limiting factor for applications, and reinforcement and improved wear resistance are major directions in current research. In here, graphitic carbon nitride (g-CN)-based hydrogels are presented. The hydrogels are formed in a two-step procedure. In the first step, a prepolymer is synthesized that leads to a significantly improved g-CN dispersibility and stability of g-CN dispersions. Hence, the g-CN content in the final hydrogels can be increased to obtain tough hydrogels. More importantly, hydrogels from charged monomers can be formed as well, which leads to lubricant properties. As such, the investigated route opens up new opportunities to fabricate functional hydrogels with significant toughness, compressibility and lubricity.

A high-throughput composite catalyst is prepared from porous carbon with an unconventional nanocube morphology decorated by nickel nanoparticles. Due to the advantageous properties of the designed carbon support, the composite combines a high surface area and a hierarchical pore structure with high functionality. Furthermore, the regularly shaped nanocubes allow for a good packing of a fixed-bed flow reactor, while the internal transport pores cannot be blocked and stay open for efficient column performance. The composite is employed as catalyst in the hydrogenation of 5 hydroxymethylfurfural (HMF) to 2,5-dimethylfuran showing good catalytic performance and overcoming the conventional problem of column blocking.

Hydrogenation reactions in water at elevated temperatures are challenging for heterogeneous catalysts. Thus, we present a simple, cheap, scalable, and sustainable approach for synthesizing an efficient and stable Ni catalyst supported on highly porous nitrogen-doped carbon (NDC) in pellet form. The performance of this catalyst was evaluated in the aqueous-phase hydrogenation of lignocellulosic biomass-derived compounds, i.e., glucose (Glu), xylose (Xyl), and vanillin (V), using a continuous-flow system. The as-prepared 35 wt% Ni on NDC catalyst exhibited a high catalytic performance in all three aqueous-phase hydrogenation reactions, i.e., the conversion of Glu, Xyl, and V was 96.3 mol%, 85 mol%, and 100 mol% and the yield of sorbitol (Sor), xylitol (Xyt), and 2-methoxy-4-methylphenol (MMP) was 82 mol%, 62 mol%, and 100 mol%, respectively. This high activity was attributed to the high specific surface area of NDC and mainly to the heterojunction effects stabilizing and adjusting the homogenously and highly dispersed Ni nanoparticles (ANi = 20 m2 g−1) on the surface of NDC. Changing the electron density in the nickel nanoparticles allows the high performance of the catalyst for a long time on stream (40 h) with minimized Ni leaching and without the loss in catalytic performance.

Waste lignocellulosic biomass is sustainable and an alternative feedstock to fossil resources. Among the lignocellulosic derived compounds, 2,5-dimethylfuran (DMF) is a promising building block for chemicals, e.g., p-xylene, and a valuable biofuel. DMF can be obtained from 5-hydroxymethylfurfural (HMF) via catalytic deoxygenation using non-noble metals such as Ni in the presence of H2. Herein, we present the synthesis of DMF from HMF using 35 wt.% Ni on nitrogen-doped carbon pellets (35Ni/NDC) as a catalyst in a continuous flow system. The conversion of HMF to DMF was studied at different hydrogen pressures, reaction temperatures, and space times. At the best reaction conditions, i.e., 423 K, 8.0 MPa, and space time 6.4 kgNi h kgHMF&minus, 1, the 35Ni/NDC catalyst exhibited high catalytic activity with HMF conversion of 99 mol% and 80 mol% of DMF. These findings can potentially contribute to the transition toward the production of sustainable fine chemicals and liquid transportation fuels.

Extremely compressible hydrogels are fabricated in one pot via sulfonic-acid-modified graphitic carbon nitride (g-CN-AHPA) as a visible light photoinitiator and reinforcer. The hydrogels show unusual compressibility upon applied stress up to 12 MPa, presenting temporary physical deformation, and remain undamaged after stress removal despite their high water content (90 wt%). Cyclic compressibility proves the fatigue resistance of the covalently and electrostatically reinforced system that possesses tissue adhesive properties, shock resistance, cut resistance, and little to no toxicity.

Lignin is one of the most important candidates for the procurement of renewable aromatics. The development of successful strategies for the production of building blocks from lignin implies the design of effective depolymerization protocols. Here we propose a continuous flow approach for the hydrogenolysis of Kraft lignin utilizing a TiN-Ni heterogeneous catalyst. The refining of commercial Kraft lignin was evaluated, showing that the catalyst can facilitate the partial depolymerization of this sulfur-containing material under very mild conditions and with short residence times. The process restitutes lignin in the form of oligomers in combination with an array of valuable single-ring aromatic compounds.

High concentration formulations of graphitic carbon nitride (g-CN) are utilized as photoinitiator and reinforcer for hydrogels. In order to integrate significant amounts of g-CN, ethylene glycol (EG) is employed as a co-solvent for the gel formation, which enables stable dispersion of up to 4 wt% g-CN. Afterwards, EG can be removed easily via solvent exchange to afford pure hydrogels. The diverse gels possess remarkably high storage moduli (up to 650 kPa for gels and 720 kPa for hydrogels) and compression moduli (up to 9.45 MPa for 4 wt% g-CN EG gel and 3.45 MPa for 4 wt% g-CN hydrogel). Full recovery without energy loss is observed for at least 20 cycles. Moreover, gel formation can be performed in a spatially controlled way utilizing photomasks with desired shapes. Therefore, the suggested method enables formation of hybrid gels by optical lithography with outstanding mechanical properties very similar to natural cartilage and tendon, and opens up opportunities for future applications in photocatalysis, additive manufacturing of biomedical implants and coating materials.

A low-cost laser-based printing setup is presented, which allows for the spot-wise patterning of surfaces with defined polymer nanolayers. These nanolayer spots serve as a “solid solvent,” embedding different chemicals, chemical building blocks, materials, or precursors and can be stacked on top of each other. By melting the spot pattern, the polymer-embedded molecules are released for chemical reaction. This enables researchers to quickly pattern a surface with different molecules and materials, mixing them directly on the surface for high-throughput chemical synthesis to generate and screen diverse microarray libraries. In contrast to expensive ink-jet or contact printing, this approach does not require premixing of inks, which enables in situ combinatorial mixing. Easy access and versatility of this patterning approach are shown by generating microarrays of various biomolecules, such as glycans for the first time, to screen interactions of antibodies and lectins. In addition, a layer-by-layer solid-phase synthesis of peptides directly on the microarray is presented. Amino acid–containing nanolayers are repeatedly laser-transferred and reacted with the functionalized acceptor surface in defined patterns. This simple system enables a reproducible array production, down to spot-to-spot distances of 100 μm, and offers a flexible and cheap alternative to expensive spotting robot technology.

Aim: Targeted biocompatible nanoplatforms presenting multiple therapeutic functions have great potential for the treatment of cancer. Materials & methods: Multifunctional nanocomposites formed by polymeric nanoparticles (PNPs) containing two cytotoxic agents – the drug alisertib and silver nanoparticles – were synthesized. These PNPs have been conjugated with a chlorotoxin, an active targeting 36-amino acid-long peptide that specifically binds to MMP‑2, a receptor overexpressed by brain cancer cells. Results: The individual and synergistic activity of these two cytotoxic agents against glioblastoma multiforme was tested both in vitro and in vivo. The induced cytotoxicity in a human glioblastoma–astrocytoma epithelial‑like cell line (U87MG) was studied in vitro through a trypan blue exclusion test after 48 and 72 h of exposure. Subsequently, the PNPs’ biodistribution in healthy animals and their effect on tumor reduction in tumor‑bearing mice were studied using PNPs radiolabeled with 99mTc. Conclusion: Tumor reduction was achieved in vivo when using silver/alisertib@PNPs–chlorotoxin., JRC.I.4-Nanobiosciences

In the quest for biocompatible nanocarriers for biomedical applications, a great deal of effort is put on engineering the nanocomposites surface in order to render them specific to the particular purpose. We developed biocompatible PLGA-b-PEG-based nanoparticles carrying a double functionality (i.e., carboxylic and acetylenic) able to serve as flexible highly selective grafting centers for cancer diagnosis and treatment. As a proof of concept, the nanocarrier was successfully functionalized with a tailored fluorescent molecule by means of click chemistry and with a targeting agent specific for glioblastoma multiforme via amidic bond formation.

An integrated method for the production of γ-valerolactone from cellulosic biomass is presented here. A combination of acidic water hydrolysis of the biomass followed by extraction with methyltetrahydrofuran is used to generate a levulinic acid feed, which is further hydrogenated into the platform chemical γ-valerolactone using RANEY® nickel as a catalyst.