Polymeric Precursor Research Articles

Preparation and optimization of La0.6Sr0.4Fe1-yCoyO3-δ cathodes for intermediate temperature solid oxide fuel cells

It is shown in this work that a synthetic route based on the auto-combustion of an ethylene glycol-metal nitrate polymerized gel precursor can be efficiently used to easily produce a range of La0.6Sr0.4Fe1-yCoyO3-δ nanopowders at moderate temperatures. We have been able to determine on air-sintered samples the effect of sintering temperature on the microstructure. At sintering temperatures as low as 1100 to1200 °C, grains are well defined with a uniform round spherical morphology and have a homogeneous sub-micrometer size distribution showing a highly densified microstructure. The electronic conductivity and thermal expansion coefficients (TEC) of sintered LSFC samples have been determined according to the variation of Fe/Co composition. Both measures clearly increase with the Co content. These materials also must exhibit chemical stability with electrolytes, most commonly used for intermediate temperature solid oxide fuel cells (IT-SOFCs). In this way, the material as obtained is optimized in terms of chemical homogeneity and good stoichiometric control, microstructural characteristics of sintered samples, and finally the adequate Cobalt content to avoid high TEC mismatch with other components of the SOFC. This is a crucial issue as it causes an important thermo¬mechanical stress; promote extensive microcraking and significant performance degradation. Finally, these cathodes must exhibit acceptable electrochemical parameters for use in IT-SOFC.

N, P co-Doped Hard Carbon Anodes for High-Performance Lithium-Ion Batteries with Enhanced Capacity Retention and Cycle Stability.

Compared to the traditional graphite anode, heteroatom-doped polymer carbon materials have high capacity retention due to their high porosity and porous structure. Therefore, they have great potential for application in lithium-ion battery (LIB) anodes. In this work,an N, P co-doped precursor polymer material (MBPp), synthesized via a one-pot method using bisphenol-A (C-source), melamine (N-source), and 9,10-Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (P-source). The resulting N, P-co-doped hard carbon materials (MBPs) were prepared at various pyrolysis temperatures, yielding microporous, mesoporous, and macroporous structures. MBP materials demonstrated excellent electrochemical performance as LIB anodes. Notably, MBP-900 achieved a reversible capacity of 262 mAh g-1 at 1000 mA g-1 (in 0.005-2.0 V voltage range) with a capacity retention rate of 97.2% after 1000 cycles. These findings highlight the significance of MBP materials, which possess numerous defects, large layer gaps, and excellent cycle stability, in advancing the development of polymer anode materials for LIBs.

Solvent Choice during Flow Assembly of Photocross-Linked Single-Chain Nanoparticles and Micelles Affects Cellular Uptake.

Polymeric micelles have widely been used as drug delivery carriers, and recently, single-chain nanoparticles (SCNPs) emerged as potential, smaller-sized, alternatives. In this work, we are comparing both NPs side by side and evaluate their ability to be internalized by breast cancer cells (MCF-7) and macrophages (RAW 264.7). To be able to generate these NPs on demand, the polymers were assembled by flow, followed by the stabilization of the structures by photocross-linking using blue light. The central aim of this work is to evaluate how the type of solvent affects self-assembly and ultimately the structure of the final NP. Therefore, a library of copolymers with different sequences, including block copolymers (AB, ABA, BAB), and statistical copolymers (rAB and rAC) was synthesized using PET-RAFT with A denoting poly(ethylene glycol) methyl ether acrylate (PEGMEA), B as 2-hydroxyethyl acrylate (HEA), and C as 4-hydroxybutyl acrylate (HBA). The polymers were conjugated with a quinoline derivative to enable the formation of cross-linked structures by photocross-linking during flow assembly. Using water as the dispersant for photocross-linking led to the preassembly of these amphiphilic polymers into compact SCNPs and cross-linked micelles, resulting in a quick photoreaction. In contrast, acetonitrile led to fully dissolved polymers but a low rate of the photoreaction. These intramolecularly cross-linked polymers were then placed in water to result in more dynamic micelles and looser SCNPs. Small-angle X-ray scattering (SAXS), dynamic light scattering (DLS), and size exclusion chromatography (SEC) coupled with a viscosity detector show that cross-linking in acetonitrile results in better-defined NPs with a shell rich in PEGMEA. Cross-linking in acetonitrile led to NPs with significantly higher cellular uptake. Interestingly, passive transport was identified as the main pathway for the delivery of our NPs on MCF-7 cells, confirmed by the uptake of NPs on cells treated with inhibitors and by red blood cells. This work underscored the importance of the polymer precursor's structure and the choice of solvent during intramolecular cross-linking in determining the drug delivery efficiency and biological behavior of SCNPs.

A Poly(2,7‐anthrylene) with peri‐Fused Porphyrin Edges

Anthracene has served as an important building block of conjugated polymers with the connecting positions playing a crucial role for the electronic structures. Herein, anthracene units have been coupled through their 2,7‐carbons to develop an unprecedented, conjugated polymer, namely, poly(2,7‐anthrylene) featuring additional peri‐fused porphyrin edges. The synthesis starts from a 2,7‐dibromo‐9‐nickel(II) porphyrinyl‐anthracene as the pivotal precursor. Polymerization is achieved by an AA‐type Yamamoto coupling, followed by a polymer‐analogous oxidative cyclodehydrogenation to obtain a peri‐fusion between porphyrin and anthracene moieties. Although further cyclodehydrogenation between the repeating units cannot be achieved in solution, the thermal treatment of the precursor polymer derived from 2,7‐dibromo‐9‐porphyrinyl‐anthracene on a metal surface realizes the full cyclodehydrogenation. The difference between solution and on‐surface reactivity can be rationalized by the larger dihedral angle between repeat units in solution, which is reduced under the pronounced interaction with the metal surface. The peri‐fusion in the title polymer gives rise to a narrow electronic band gap optical absorptions extending far into the near‐infrared region. Oligomeric models are synthesized as well to support the analyses of the electronic and photophysical properties.

A Poly(2,7-anthrylene) with peri-Fused Porphyrin Edges.

Anthracene has served as an important building block of conjugated polymers with the connecting positions playing a crucial role for the electronic structures. Herein, anthracene units have been coupled through their 2,7-carbons to develop an unprecedented, conjugated polymer, namely, poly(2,7-anthrylene) featuring additional peri-fused porphyrin edges. The synthesis starts from a 2,7-dibromo-9-nickel(II) porphyrinyl-anthracene as the pivotal precursor. Polymerization is achieved by an AA-type Yamamoto coupling, followed by a polymer-analogous oxidative cyclodehydrogenation to obtain a peri-fusion between porphyrin and anthracene moieties. Although further cyclodehydrogenation between the repeating units cannot be achieved in solution, the thermal treatment of the precursor polymer derived from 2,7-dibromo-9-porphyrinyl-anthracene on a metal surface realizes the full cyclodehydrogenation. The difference between solution and on-surface reactivity can be rationalized by the larger dihedral angle between repeat units in solution, which is reduced under the pronounced interaction with the metal surface. The peri-fusion in the title polymer gives rise to a narrow electronic band gap optical absorptions extending far into the near-infrared region. Oligomeric models are synthesized as well to support the analyses of the electronic and photophysical properties.

Tracing the graphitization of polymers: A novel approach for direct atomic-scale visualization

Due to its excellent physical, chemical, and electrochemical characteristics, pyrolytic carbon has become a promising material for a wide range of advanced technologies. Pyrolytic carbon can be obtained through the pyrolysis of a polymeric carbon precursor at high temperatures and in inert atmosphere. By tuning the pyrolysis conditions, the hybridization of carbon atoms and thus the physicochemical properties of the derived carbon can be tailored. Advancing its development requires a deeper understanding of the graphitization process. In this context, an in situ microstructural analysis of the pyrolysis process is needed. This work presents the microfabrication of suspended polymer thin film structures on transmission electron microscopy heating chips, by two-photon polymerization 3D printing. We visualized graphitization of these films during in situ transmission electron microscopy heating studies. The favorable identified conditions are a thin film with a thickness of around 700 nm pre-pyrolysis, a pyrolysis profile reaching a maximum temperature of 1300°C and a minimum of 2 h of dwell at this temperature. An increase in the number of stacked graphene layers was observed over dwell time. Overall, the developed method has the potential to enable the visualization of graphitization of different polymer precursors and thus help predict the microstructure and properties of pyrolytic carbon depending on its fabrication conditions.

Macromolecular Function Emerging from Intramolecular Peptide Stapling of Synthetic Polymers.

Protein function results from the precise folding of polypeptides into bespoke architectures. Taking inspiration from nature, the field of single-chain nanoparticles (SCNPs), intramolecularly crosslinked synthetic polymers, emerged. In contrast to nature, the function of SCNPs is generally defined by the parent polymer or the applied crosslinker, rather than by the crosslinking process itself. This work explores the cyanopyridine-aminothiol click reaction to crosslink peptide-decorated polymers intra-macromolecularly to endow the resulting SCNPs with emerging functionality, resulting from the conversion of N-terminal cysteine units into pyridine-thiazolines. Dimethylacrylamide based polymers with different cysteine-terminated amino acid sequences tethered to their sidechains are investigated (P1 (C),P2 (GDHC),P3 (GDSC)) and intramolecularly crosslinked into SCNPs. Since the deprotection of the parent polymers yields disulfide-based SCNPs, a direct comparison between disulfide and pyridine-thiazolines crosslinked SCNPs is possible. This comparison revealed two emerging properties of the pyridine-thiazoline crosslinked SCNPs: 1) The formation of pyridine-thiazolines gave rise to metal binding sites within the SCNP, which complexed iron. 2) Depending on the peptide sequence in the precursor polymer, the hydrolytic activity of the peptide sequences is either increased (GDHC) or decreased (GDSC) uponpyridine-thiazoline formation compared to identical SCNPs based on disulfide crosslinks.

Developing high-performance oxygen electrodes for intermediate solid oxide cells (SOC) prepared by Ce0.8Gd0.2O2−δ backbone infiltration

Gd0.2Ce0.8O 2−δ (GDC) porous backbone infiltration with La0.6Sr0.4CoO3−δ (LSC), PrOx and LSC: PrOx as a composite oxygen electrode for intermediate solid oxide cells are conducted within the scope of this work. Samples were characterized using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and electrochemical impedance spectroscopy (EIS). A uniform distribution of the infiltrated material inside the backbone and at the electrolyte-backbone interface was achieved. EIS measurements on the prepared symmetrical samples showed electrode polarization resistance (Rp) values of 0.029 Ω.cm², 0.23 Ω.cm², and 0.44 Ω.cm² for LSC, LSC: PrOx, and PrOx at 600 °C, respectively. Long-term stability measurements at 600 °C for 100 h showed a slight increase in polarization resistance during the measurement period. Fuel cell measurements of commercial cells (Elcogen) with porous oxygen electrode consisting of GDC infiltrated with LSC showed an increase in power density compared to the reference cell with a value of 0.53 W.cm− 2 obtained at 600 °C. It is proven that infiltration via polymeric precursor into porous scaffolds as backbone oxygen electrode layer is effective and convenient method to develop high performance and stable solid oxide cells.

Electric Properties Change during Morphological Evolution of CeO2 Nanostructures: Synergy between Bulk and Surface Defects.

CeO2 samples were synthesized via the polymeric precursor method at different calcination temperatures. Electric properties were investigated using positron annihilation lifetime spectroscopy, electron paramagnetic resonance spectroscopy, and complex impedance spectroscopy. Reduction in the specific surface area of the particles with increasing calcination temperature along with morphological changes were observed. PALS depicted doubly ionized oxygen vacancies surrounded by two Ce3+ atoms, while the EPR spectroscopy showed a singly ionized oxygen vacancy surrounded by Ce3+ and Ce4+ ions. Impedance measurements unraveled the presence of polarons, while thermal treatments led to a lower electrical conductance, as the calcination temperature increased.

Steric Hindrance Engineering to Modulate the Closed Pores Formation of Polymer-Derived Hard Carbon for High-Performance Sodium-Ion Batteries.

The closed pores play a critical role in improving the sodium storage capacity of hard carbon (HC) anode, however, their formation mechanism as well as the efficient modulation strategy at molecular level in the polymer-derived HCs is still lacking. In this work, the steric hindrance effect has been proposed to create closed pores in the polymer-derived HCs for the first time through grafting the aromatic rings within and between the main chains in the precursor. The experimental data and theoretical calculation demonstrate that steric-hindrance effect from the aromatic ring side group can increase backbone rigidity and the internal free volumes in the polymer precursor, which can prevent the over graphitization and facilitate the formation of closed pores during the carbonization process. As a result, the as-prepared HC anode exhibits a remarkably enhanced discharge capacity of 340.3 mAh/g at 0.1 C, improved rate performance (210.7 mAh/g at 5 C) as well as boosted cycling stability (86.4 % over 1000 cycles at 2 C). This work provides a new insight into the formation mechanisms of closed pores via steric hindrance engineering, which can shed light on the development of high-performance polymer-derived HC anode for sodium-ion batteries.

Photo-crosslinking injectable Photothermal antibacterial hydrogel based on quaternary ammonium grafted chitosan and hyaluronic acid for infected wound healing

Antibacterial hydrogels not only provide a better environment for skin wounds to avoid infection but also accelerate wound healing. Herein, chitosan modified by a quaternary ammonium salt (CQ), and hyaluronic acid grafted with methacrylate (HM) were designed and synthesized to prepare an injectable photo-crosslinking hydrogel for wound dressing with inherent antibacterial and photothermal properties. CQ and HM exhibited excellent biocompatibility, improved water retention, and antibacterial activity, illustrating vast potential as an antibacterial material in various applications. MXene, a type of 2D nanomaterial, has been widely researched due to its photothermal properties. The CQ and HM polymer precursor could be mixed with Mxene and then crosslinked with 395 nm UV radiation under mild conditions to form a 3D network structure CQ-HM/MXene hydrogel. This hydrogel displayed an appropriate swelling ratio, elastic modulus, photothermal property and excellent biocompatibility. The injectable property of the hydrogel allowed it to easily cover the wound. In vitro and in vivo studies showed that the injectable hydrogel had low cytotoxicity and excellent antibacterial properties, which could help promote wound healing. In summary, this novel CQ-HA/MXene hydrogel has the potential for application in skin wound healing due to inherent antibacterial activity and photothermal effect.

Fast and scalable preparation of metal–organic coordination polymeric precursor for bifunctional electrocatalysts for high performance lithium–oxygen batteries

The Metal-organic coordination polymers (MOCPs) with structural and functional diversity are considered effective cathode materials for Lithium-oxygen batteries (LOBs). Conventional synthesis methods make it difficult to obtain large quantities of materials. Here, A highly active low-cost Co-decorated N-doped carbon oxygen cathode catalyst (Co–N–C) was synthesized using a fast and scalable method based on positive and negative charge coordination. Rapid synthesis of MOCPs depends on the addition of base sites. A theory of “Lewis’s base-assisted rapid synthesis” was proposed. Co-N-C as LOBs air cathode showed 150 cycles with 1000 mAh g-1 at 500 mA g-1. The fast and scalable synthesis method can provide a feasible strategy for large-scale production of oxygen electrocatalysts for LOBs.

Synthesis and Electrochemical Performance of High‐Entropy Spinel‐Type Oxides Derived from Multimetallic Polymeric Precursors

High‐entropy spinel‐type oxides are synthesized by a modified Pechini process, wet chemistry approach, and solid‐state synthesis method and characterized as anode materials for Li‐ion batteries. The Pechini process that involves chelation and polyesterification reactions facilitates the formation of high‐entropy spinel‐type oxides without compositional segregation at ≈600 °C as confirmed by in situ and ex situ XRD. XAFS analysis and the Rietveld refinement of room‐temperature neutron diffraction data suggest the composition (Mn0.05Fe0.48Co0.47, tetrahedral)(Cr0.61Mn0.52Fe0.11Co0.09Ni0.68, octahedral)O4 for phase‐pure specimens. Compared to high‐entropy spinel‐type oxides synthesized by the solid‐state method, the precursor‐derived materials demonstrate higher specific capacity as anodes, in which the materials without citric acid addition exhibit low capacity fading at high current densities and maintained a capacity of ≈200 mAh g−1 after 1000 cycles. The generation of a rock‐salt‐type phase during cycling is confirmed for the first time by in situ charging–discharging XRD. The charging–discharging of this anode material is achieved mainly through the embedding–disembedding of lithium ions in the lattice of the generated rock‐salt‐type phase.

Nanoporous amorphous carbon nanopillars with lightweight, ultrahigh strength, large fracture strain, and high damping capability

Simultaneous achievement of lightweight, ultrahigh strength, large fracture strain, and high damping capability is challenging because some of these mechanical properties are mutually exclusive. Here, we utilize self-assembled polymeric carbon precursor materials in combination with scalable nano-imprinting lithography to produce nanoporous carbon nanopillars. Remarkably, nanoporosity induced via sacrificial template significantly reduces the mass density of amorphous carbon to 0.66 ~ 0.82 g cm−3 while the yield and fracture strengths of nanoporous carbon nanopillars are higher than those of most engineering materials with the similar mass density. Moreover, these nanopillars display both elastic and plastic behavior with large fracture strain. A reversible part of the sp2-to-sp3 transition produces large elastic strain and a high loss factor (up to 0.033) comparable to Ni-Ti shape memory alloys. The irreversible part of the sp2-to-sp3 transition enables plastic deformation, leading to a large fracture strain of up to 35%. These findings are substantiated using simulation studies. None of the existing structural materials exhibit a comparable combination of mass density, strength, deformability, and damping capability. Hence, the results of this study illustrate the potential of both dense and nanoporous amorphous carbon materials as superior structural nanomaterials.

Improving adhesion strength between steel and 2K polyurethane containing organic–inorganic hybrid nanoparticles and its performance optimization

This research has developed a novel adhesion promoter using organic-inorganic hybrid nanoparticles (ATS) to address existing limitations, such as the cumbersome separate coating and drying stages and insufficient adhesion. ATS was synthesized through hydrolysis-condensation reactions of an alkoxysilane-functionalized amphiphilic polymer (AFAP) precursor and 3-aminopropyltriethoxysilane (APTES). When directly mixed with resin part of polyurethane, ATS significantly enhanced the adhesion strength of 2 K PU to steel substrates without altering the mechanical properties or chemical structure of the polyurethane. An optimization process was conducted to determine the ideal mixing ratio of ATS with other components of 2 K PU, including different types of glycols (butylene glycol, propylene glycol, and ethylene glycol) and polyols to achieve the highest adhesive performance. The results showed that 2 K PU resin formed by using a mixture of polycaprolactone diol (PCD) and butylene glycol (BG) containing ATS (1−2) with nanoscale size (30.86 nm) exhibited superior adhesion performance over the other modified 2 K PUs and was 2.16 times higher than the common 2 K PU. These results were further validated via predictive model following response surface methodology to assess the precise impact of three parameters: the amount of AFAP (X1), amount of APTES (X2), and amount of BG (X3) on the adhesion strength of 2 K PU. The properties of different types of ATS and modified 2 K PU including particle size, degree of condensation, moisture content, molecular structure, molecular weight, hydrogen bonding intensity, microstructure morphology, and adhesion strength, were characterized.

TMAB modified NiFe2O4 nanoparticles for the Effective removal of Eriochrome Black-T azo dye

The Eriochrome Black-T (EBT) azo dye was removed from aqueous solution using TMAB (tetramethyl ammonium bromide) stabilised NiFe2O4 (TMAB@NFO) nanoparticles, which have been synthesized through polymeric precursor method. X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectra (FTIR) were used to analyse the TMAB@NFO nanoparticles. Adsorption studies were conducted under a variety of conditions, including pH, adsorbent dosage, and contact time, intraparticle diffusion, pseudo-first- and pseudo-second-order kinetic models were used to analyse the kinetic data. According to the systematic study of adsorption isotherms and kinetics models, TMAB@NFO nanoparticles will adsorb EBT dye utilising the Freundlich model and pseudo-second-order kinetics. The intraparticle diffusion model revealed a linear relationship (R2 - 0.98, 0.97, and 0.94 for TMAB@NiFe2O4 and bare NiFe2O4-NPs), demonstrating how surface modification influences the overall EBT adsorption process and the pore diffusion rate. Additionally, the manufactured nano adsorbents of NiFe2O4 were effectively regenerated and reused after the treatments up to four times following the elimination of 89% of EBT dye by TMAB@NiFe2O4-NPs. The results have demonstrated the enormous potential of TMAB @NiFe2O4-NPs to eliminate EBT in a practical way. KEY WORDS: Tetramethyl ammonium bromide, NiFe2O4, EBT, Surface capping, Adsorption, Kinetics Bull. Chem. Soc. Ethiop. 2024, 38(6), 1569-1581. DOI: https://dx.doi.org/10.4314/bcse.v38i6.6

Wavy Graphene Nanoribbons Containing Periodic Eight-Membered Rings for Light-Emitting Electrochemical Cells.

Precision graphene nanoribbons (GNRs) offer distinctive physicochemical properties that are highly dependent on their geometric topologies, thereby holding great potential for applications in carbon-based optoelectronics and spintronics. While the edge structure and width control has been a popular strategy for engineering the optoelectronic properties of GNRs, non-hexagonal-ring-containing GNRs remain underexplored due to synthetic challenges, despite offering an equally high potential for tailored properties. Herein, we report the synthesis of a wavy GNR (wGNR) embedding periodic eight-membered rings into its carbon skeleton, which is achieved by the A2B2-type Diels-Alder polymerization between dibenzocyclooctadiyne (6) and dicyclopenta[e,l]pyrene-5,11-dione derivative (8), followed by a selective Scholl reaction of the obtained ladder-type polymer (LTP) precursor. The obtained wGNR, with a length of up to 30 nm, is thoroughly characterized by solid-state NMR, FT-IR, Raman, and UV-Vis spectroscopy with the support of DFT calculations. The non-planar geometry of wGNR efficiently prevents the inter-ribbon π-π aggregation, leading to photoluminescence in solution. Consequently, the wGNR can function as an emissive layer for organic light-emitting electrochemical cells (OLECs), offering a proof-of-concept exploration in implementing luminescent GNRs into optoelectronic devices. The fast-responding OLECs employing wGNR will pave the way for advancements in OLEC technology and other optoelectronic devices.

Review on the Polymeric and Chelate Gel Precursor for Li-Ion Battery Cathode Material Synthesis.

The rapid design of advanced materials depends on synthesis parameters and design. A wide range of materials can be synthesized using precursor reactions based on chelated gel and organic polymeric gel pathways. The desire to develop high-performance lithium-ion rechargeable batteries has motivated decades of research on the synthesis of battery active material particles with precise control of composition, phase-purity, and morphology. Among the most common methods reported in the literature to prepare precursors for lithium-ion battery active materials, sol-gel is characterized by simplicity, homogeneous mixing, and tuning of the particle shape. The chelate gel and organic polymeric gel precursor-based sol-gel method is efficient to promote desirable reaction conditions. Both precursor routes are commonly used to synthesize lithium-ion battery cathode active materials from raw materials such as inorganic salts in aqueous solutions or organic solvents. The purpose of this review is to discuss synthesis procedure and summarize the progress that has been made in producing crystalline particles of tunable and complex morphologies by sol-gel synthesis that can be used as active materials for lithium-ion batteries.

Controlling the optoelectronic properties of nitrogen-doped carbon quantum dots using biomass-derived precursors in a continuous flow system

The synthesis of carbon quantum dots (CQDs) from high molecular weight biomass-derived precursors poses a significant challenge due to the complex molecular structures and low conversion efficiency. This work demonstrates a green, rapid, and sustainable continuous hydrothermal flow synthesis (CHFS) approach for nitrogen-doped carbon quantum dots (NCQDs) from various biomass-derived precursors, including high molecular weight polymeric sources like chitosan, lignin, and humic acid. We find that the precursor structure significantly impacts the size of the fabricated NCQDs and their optical properties. Citric acid, a low molecular weight precursor, yields NCQDs with excitation-independent emission, higher quantum yields, and low non-radiative losses, while NCQDs derived from polymeric precursors exhibit excitation-dependent, red-shifted, and lower efficiency emission. Theoretical calculations, performed to understand the configuration and distribution of nitrogen dopants within the NCQD structure, show that pyridinic and graphitic nitrogen atoms exhibit a strong preference to aggregate near the centre of the edge of the NCQD and not in the vertices nor in the graphitic core, thus affecting the HOMO and LUMO, bandgap, and light absorption and emission wavelengths. The life cycle assessment (LCA) analysis highlights the green and scalable advantages of the CHFS process for producing NCQDs compared to batch methods, making it a sustainable and economically viable approach for large-scale NCQD synthesis from high molecular weight biomass-derived precursors. Hence, the combination of experimental data and theoretical calculations provides a comprehensive understanding of the structure-property relationships in these NCQDs.

Developing Enhanced SiTiOC/PS/TiO2 hybrid aerogels with excellent mechanical properties and ultra-low thermal conductivity

Ceramic aerogels exhibit an extremely high porosity, low weight, and exceptionally low thermal conductivity, making them suitable as insulating materials for use in challenging environments. The widespread application of conventional ceramic aerogels is typically constrained by the fragile nature of the material and its high-temperature infrared radiation transparency. Here, we successfully prepared SiTiOC/PS/TiO2 hybrid aerogels by effectively synthesizing them using polyvinyl alcohol (PVA) as the carbon skeleton and reinforcing them with polystyrene microspheres (PS) and PAN nanofibers loaded with TiO2 (TiO2/PAN NFs), and TiO2/PAN NFs as shading material. This was achieved through a combination of the polymer precursor transformation method, sol-gel method, and techniques such as freeze-drying and electrostatic spinning. The findings indicated that the fabricated SiTiOC/PS/TiO2 hybrid aerogels exhibited a lightweight structure, exceptionally high infrared reflectivity, remarkably low thermal conductivity, and outstanding mechanical characteristics. The successful synthesis of the SiTiOC/PS/TiO2 hybrid aerogels offers a novel approach for advancing the production of various thermal insulation materials.