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Pinus radiata bark is a rich source of polyphenols, which are mainly composed of proanthocyanidins. This study aimed to utilize P. radiata bark as a polyol source for bio-foam production in the future. Polyphenol-rich alkaline extracts (AEs) from P. radiata bark were prepared by mild alkaline treatment and then derivatized with propylene oxide (PO). Hydroxypropylated alkaline extracts (HAEs) with varying molar substitutions (MS 0.4–8.0) were characterized by FT-IR, NMR, GPC, TGA, and DSC. The hydroxyl value and solubility in commercial polyols were also determined. The molecular weights of the acetylated HAEs (Ac-HAEs) were found to be 4000 to 4900 Da. Analyses of FT-IR of HAEs and [sup.1]H NMR of Ac-HAEs indicated that the aromatic hydroxyl groups were hydroxypropylated and showed an increase in aliphatic hydroxyl group content. The glass transition temperature (T[sub.g]) of AE and HAEs were 58 to 60 °C, showing little difference. The hydroxyl value increased as the hydroxypropylation proceeded. Although salts were produced upon neutralization after hydroxypropylation, HAEs still showed suitable solubility in polyether and polyester polyols; HAEs dissolved well in polyether polyol, PEG#400, and solubility reached about 50% (w/w). This indicated that neutralized HAEs could be directly applied to bio-foam production even without removing salts.

Sugar compounds are an important part of biomass resources, and their catalytic conversion can prepare a series of platform compounds, such as lactic acid and polyols. One of the key steps is the isomerization of aldoses to ketoses. However, finding a simple method to efficiently convert aldoses to ketoses remains a great challenge. Herein, we report a core-shell structured catalyst, Pt/SiO.sub.2@Mg(OH).sub.2, for the efficient conversion of xylose as well as the further conversion of xylose to xylulose. Xylose, a five-carbon sugar unit with the highest content in biomass, was used as the object of study to determine the optimal reaction conditions in the aqueous system by adjusting the loading amount of Mg(OH).sub.2, catalyst addition, reaction temperature, and reaction time: In the optimum aqueous conditions, the yield of xylulose was 23.61%. We also investigated the effect of solvent effects on the hydrothermal reaction and determined the optimal solvent ratio, the yield of xylulose reached 31.74% at H.sub.2O:MeOH (8:2). We anticipate that this research result can provide a theoretical basis and reference for the industrialized production of subsequent sugar isomerization.

Sugar compounds are an important part of biomass resources, and their catalytic conversion can prepare a series of platform compounds, such as lactic acid and polyols. One of the key steps is the isomerization of aldoses to ketoses. However, finding a simple method to efficiently convert aldoses to ketoses remains a great challenge. Herein, we report a core-shell structured catalyst, Pt/SiO.sub.2@Mg(OH).sub.2, for the efficient conversion of xylose as well as the further conversion of xylose to xylulose. Xylose, a five-carbon sugar unit with the highest content in biomass, was used as the object of study to determine the optimal reaction conditions in the aqueous system by adjusting the loading amount of Mg(OH).sub.2, catalyst addition, reaction temperature, and reaction time: In the optimum aqueous conditions, the yield of xylulose was 23.61%. We also investigated the effect of solvent effects on the hydrothermal reaction and determined the optimal solvent ratio, the yield of xylulose reached 31.74% at H.sub.2O:MeOH (8:2). We anticipate that this research result can provide a theoretical basis and reference for the industrialized production of subsequent sugar isomerization. Graphical

Nanocomposites have been demonstrated as potential materials for biosensors to biomedicine applications. However, the crystallization mechanism of nanocomposites has not been thoroughly investigated so far. Cellulose nanofiber is used as a new kind of nano-filler to modify the biodegradable polymer to prepare nanocomposites. Banana cellulose nanofibers/polycaprolactone composite membranes (BNCF/PCL) and banana cellulose nanofibers grafted with polycaprolactone/polycaprolactone composite membranes (BGCL/PCL) were prepared, respectively. To explore the effects of BNCF and BGCL on the crystallization properties of PCL. SEM, POM, and DSC were used to study the crystallization of PCL, BNCF/PCL, and BGCL/PCL films. Mo's method was applied to study the non-isothermal kinetics of BNCF/PCL films, Avarmi and Jeziorny's models successfully predict the non-isothermal kinetics of BGCL/PCL films. The results showed that BNCF promoted the crystallization of BNCF/PCL films. The crystallization peak temperature of BNCF/PCL films was 4.11 â higher than pure PCL, and the crystallinity was 5.34% higher than that of pure PCL. The crystallization peak temperature of the BGCL/PCL films decreased slightly, but the crystallinity increased by 3.78%. The crystal growth modes of BNCF/PCL films and BGCL/PCL films were consistent with the three-dimensional growth of heterogeneous nucleation, BNCF/PCL films with average Avrami index n ranging from 2.7 to 3.9, and the BGCL/PCL films with n ranging from 2.5 to 3.2. Furthermore, the micrographs of polarized optical microscopy (POM) supported the kinetics results. This study makes a deep insight into the effect of cellulose nanofiber on the crystallization of biodegradable aliphatic polyesters.

During the growth of lead halide perovskite single crystals (SCs) with the conventional inverse temperature crystallization (ITC) method, the blast nucleation of the precursor under supersaturation conditions is always unavoidable. In the current study, three kinds of additives namely methanol (MOE), ethyl alcohol (EtOH), and polyethylene glycol (PEG) are introduced to regulate the growth of CsPbBr[sub.3] SCs. Benefiting from the strong anchoring hydroxy groups (-OH) with the Pb[sup.2+] species, large-sized CsPbBr[sub.3] crystals with reduced defect densities were prepared (PEG-regulated). In addition, the viscosity of the precursor solution increases after adding PEG additive, which provides a more stabilized environment for crystal growth. Finally, the photodetectors prepared from our PEG-tuned CsPbBr[sub.3] SCs show a responsivity of 2.25 A/W and a detectivity of 6.06 × 10[sup.11] Jones, demonstrating the potential of CsPbBr[sub.3] SCs for photo-detecting applications.

Myo-inositol polyalcohol is a characteristic component of natural and concentrated grape musts (CMs), and Regulation (EU) no. 1308/2013 prescribes its presence as a marker of the authenticity of rectified concentrated must (RCM). Other polyalcohols besides myo-inositol, such as scyllo-inositol or minor sugars, could be considered authenticity markers, but an extensive search in the literature yielded no exhaustively investigated study of their concentration variability in genuine products. The aim of this study was to create an extensive national data bank of minor carbohydrates profiles and investigate the impact of the geographical origin and the different vintages on the concentration of these compounds; to this end, 450 authentic Italian grape musts of different varieties were sampled and analyzed during the harvest season in 2019, 2020, and 2021. The grape musts from the Italian wine-growing areas CII and CIIIb had myo- and scyllo-inositol contents always higher than 756 and 39 mg/kg of sugar, respectively. Conversely, also considering other mono- and disaccharides, sucrose, sorbitol, lactose, maltose, and isomaltose showed contents always lower than 534, 1207, 390, 2222, and 1639 mg/kg of sugar, respectively. The general applicability to the CM and RCM of the proposed authenticity thresholds, established in the must, was demonstrated by studying the influence of must concentration on the myo- and scyllo-inositol content. Inter-laboratory comparison experiments were also conducted to harmonize and characterize laboratory methods and validate the analytical dataset. Based on the obtained results, the text of the EU legislation (Reg. (EU) 1308/2013), which defines the characteristics of the must and the CRM product, should be revised.

A series of mono- and bis-polyethylene glycol (PEG)-substituted BF[sub.2]-azadipyrromethene fluorophores have been synthesized with emissions in the near-infrared region (700–800 nm) for the purpose of fluorescence guided intraoperative imaging; chiefly ureter imaging. The Bis-PEGylation of fluorophores resulted in higher aqueous fluorescence quantum yields, with PEG chain lengths of 2.9 to 4.6 kDa being optimal. Fluorescence ureter identification was possible in a rodent model with the preference for renal excretion notable through comparative fluorescence intensities from the ureters, kidneys and liver. Ureteral identification was also successfully performed in a larger animal porcine model under abdominal surgical conditions. Three tested doses of 0.5, 0.25 and 0.1 mg/kg all successfully identified fluorescent ureters within 20 min of administration which was sustained up to 120 min. 3-D emission heat map imaging allowed the spatial and temporal changes in intensity due to the distinctive peristaltic waves of urine being transferred from the kidneys to the bladder to be identified. As the emission of these fluorophores could be spectrally distinguished from the clinically-used perfusion dye indocyanine green, it is envisaged that their combined use could be a step towards intraoperative colour coding of different tissues.

The catalytic reduction of toxic 4-Nitrophenol (4-NP) to valuable 4-aminophenol is highly important for environmental remediation. However, developing catalysts with high activity, good recyclability, and facile preparation remains challenging. Herein, Ag@Fe[sub.3]O[sub.4] nanocomposites were controllably synthesized with a facile one-pot polyol method. By varying the Ag:Fe precursor ratio, the structure could be tuned from dense and porous core-shell to Janus architectures. The porous Ag@Fe[sub.3]O[sub.4] nanoreactors (Ag:Fe-0.4) exhibited exceptional catalytic performance, achieving complete 4-NP reduction within 75 s, with an apparent rate constant (k) of 6.29 × 10[sup.−2] s[sup.−1], a normalized rate constant (kn) of 3742 s[sup.−1] mmol[sup.−1], and a TOF value of 1042 h[sup.−1]. XPS results verified that the excellent activity originated from the porous structure and interfacial charge transfer from Ag to Fe[sub.3]O[sub.4]. The catalysts showed super-paramagnetism and could be reused for at least eight cycles with >95% conversion retained. It also displayed high efficiency in reducing diverse nitroaromatics and in natural water. This work highlights the significance of structural and electronic modulation, providing a scalable strategy for magnetically recyclable catalysts toward environmental remediation and heterogeneous catalysis.

The exploration of efficient catalysts for the ring-opening polymerization of cyclic esters has significant implications for the synthesis of biocompatible and biodegradable polymers. In this work, the simple catalyst lithium bis(trimethylsilyl)amide (LiHMDS) with high activity was explored in detail for the synthesis of polylactide (PLA). Using LiHMDS as the catalyst, various cyclic esters were polymerized to obtain diverse sustainable polyesters, such as poly(lactide), poly(δ-valerolactone), and poly(caprolactone), with controlled molecular weights and narrow molecular weight distributions. PLA synthesis was accomplished in just a few minutes at room temperature, contributing to the sustainable advancement of this polymer.

Using [sup.1]H NMR spectroscopy, we studied the relative mobility of the NO[sub.2] group in 1-alkyl-5-nitro-1,2,4-triazoles in the reaction of nucleophilic heterocyclic substitution by aliphatic oligoethers. The main pathways of the SNipso substitution process and the composition of resultant products from competitive reactions were examined, and the key factors influencing the relative mobility of the nitro group, such as the nitrotriazole substrate constitution, the carbon skeleton length of the O-nucleophilic agent and the process conditions, were discussed. Several independent competitive reactions directed towards the substitution of the nitro group at position C(5) in the alkyltriazole substrate by different types of nucleophiles such as alkoxide-, hydroxide- and triazolonate anions were observed to take place under conditions used. The major reaction yielded oligoethers containing terminal alkyltriazole heterocycles. Secondary reactions occurred to form the corresponding triazolone and N–C triazolyl triazolone structures in the reaction system. Additionally, in excess of the alkaline agent, alkaline hydrolysis was observed to proceed at the final stages of the process involving the O-nucleophile having a longer oligoether backbone in the series studied, leading to the formation of new O-nucleophilic sites. The obtained findings can provide a foundation for devising a method for the modification of a wide range of commercially available aliphatic oligo- or polyethers to prepare functional macromolecules whose terminals carry bioactive 1,2,4-triazole heterocycles located at a desired distance from each other.