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Fluorescence emissionλ_maxred-shifts with increasing DP in Vy₄HC co-oligomers.

 

This study offers an updated bioeconomy perspective on biobased routes to high‐purity silicon and silica in the context of the societal, economic and environmental trends reshaping chemical processes. We summarize the main aspects of the green chemistry technologies capable of transforming current production methods. Coincidentally, we discuss selected industrial and economic aspects. Finally, we offer perspectives of how said technologies could/will reshape current chemical and energy production.

 

Realizing more holistic electrification in society to disengage current dependence on nonrenewable fuels requires balancing between energy storage mechanisms and actual environmental benefits gained from the transition from traditional resources. Given that the majority of greenhouse gas emissions in battery value chains originate from material mining and production, silicon carbide (SiC) derived from the agricultural waste, rice hull ash (RHA), is introduced as an environmentally-benign alternate anode material. SiC with hard carbon (SiC/HC) exhibits capacity increases on long-term cycling, reaching capacities of >950 mAh g⁻¹competitive with elemental Si with complementary porosity. Herein, a relatively low amount (<30 wt%) of graphite added to SiC/HC composites greatly promotes capacity increases while retaining sustainability. Comparison between graphite contents were optimal at ≈30 wt% graphite (SiC/HC/30G) boosted performance, doubling capacity increase rates and subsequently saving >70% time to reach target specific capacities at C/10. At 2C, SiC/HC/30G offers enhanced specific capacities at ≈220 mAh g⁻¹. The positive effects from the coincidentally formed HC are demonstrated by oxidizing HC to form SiC/O, followed by graphite addition. Experimental post-mortem analyses support that SiC/graphite composites provide a promising solution for implementing agricultural waste-derived material for next-generation lithium storage.

 

Multiple reviews have been written concerning conjugated macromonomers and polymers both as general descriptions and for specific applications. In most examples, conjugation occurs via electronic communication via continuous overlap of π orbitals, most often on carbon. These systems can be considered to offer traditional forms of conjugation. In this review, we attempt to survey macromonomers and polymers that offer conjugation involving novel forms of carbon and/or other elements but with conjugation achieved via other bonding formats, including many where the mechanism(s) whereby such behavior is observed remain unresolved. In particular, this review emphasizes silsesquioxane containing polymeric materials that offer properties found typically in conjugated polymers. However, conjugation in these polymers appears to occur via saturated siloxane bonds within monomeric units that make up a variety of polymer systems. Multiple photophysical analytical methods are used as a means to demonstrate conjugation in systems where traditional conjugation is not apparent. 

Here, we report the synthesis of DD SQ terpolymers with alternating biphenyl/terphenyl/stilbene and thiophene/hexylthiophene/bithiophene/thieno- thiophene linkers. These terpolymers were characterized using 1H and 13C nuclear magnetic resonance, gel permeation chromatography, matrix-assisted laser desorption/time-of-flight spectrometry, thermogravimetric analysis, and Fourier- transform infrared with the goal of combining long-wavelength emissions with high quantum yields. Density functional theory modeling studies using the Vienna ab initio simulation package and Gaussian 16 methods were also explored in attempts to determine HOMO-LUMO electronic configurations. Terpolymers’ UV−vis properties demonstrate an emission intermediate between the respective copolymers rather than emission from both units as would be expected from physical mixtures, supporting electronic communication along polymer chains and through cages linked via disiloxane units as seen in previous reports on copolymers of the same systems. In addition, terpolymers of DD, thiophene, and terphenyl/ stilbene offer ΦF that improved from 0.09 for DD/thiophene to 0.20 and 0.24, respectively. Compared to the corresponding terphenyl and stilbene copolymers, terpolymers display 35 nm red-shifted emissions, suggesting that it is possible to combine features of both copolymers in a single terpolymer, suggesting new opportunities to tailor photophysical properties by modifying structures, especially in systems with disiloxane linkers. 

Phase‐pure [NiO]_0.5[Al₂O₃]_0.5spinel nanoparticles (NPs) with limited aggregation were obtained via liquid‐feed flame spray pyrolysis (LF‐FSP) by combusting metalloorganic precursor solutions. Thereafter “chocolate chip‐like” Ni_x[NiO_0.5‐x][Al₂O₃]_0.5nanoparticles consisting of primary [NiO_0.5‐x][Al₂O₃]_0.5particles with average particle sizes of 40‐60 nm decorated with Ni metal particles (<10 nm in diameter) dispersed on the surface were synthesized by heat treating the spinel NPs at 800°C/7 h in flowing 5% H₂:N₂100 mL/min in a fluidized bed reactor. The synthesized materials were characterized using TEM, XRD, FTIR, and TGA/DTA. The Ni depleted areas consist primarily of γ‐Al₂O₃. The Ni content (800°C) was determined by TGA to be ≈11.3 wt.% based on TGA oxidation behavior. The successful synthesis of such nanocomposites with limited aggregation on a high temperature support provides a facile route to synthesize well‐defined NP catalysts. This work serves as a baseline study for an accompanying paper, wherein thin, flexible, dense films made from these same NPs are used as regenerable catalysts for carbon nanotube syntheses.