Construction of Pt/Ni/NiFe2O4/C nanocomposite with one dimensional hollow structure for portable glucose sensing application.

Designing portable electrochemical sensors combined with highly efficient glucose oxidation electrodes offers a significant opportunity for convenient glucose detection. In this report, we present the design and preparation of platinum deposited Ni/NiFe2O4/Carbon composite (Pt/Ni/NiFe2O4/C) derived from Ni/Fe metal-organic frameworks (MOFs) followed by Pt deposition. Energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and electron microscopy (EM) were utilized to analyze the crystal structure, morphology, and chemical composition of the resulting materials. The glucose sensing capabilities of the optimal Pt/Ni/NiFe2O4/C-3 were assessed using amperometry methods on a smartphone-based portable device. Acting as a nonenzymatic glucose sensor, the Pt/Ni/NiFe2O4/C-3 electrode demonstrated notable sensitivity and a low limit of detection for glucose. The portable sensor exhibits high sensitivities of 131.88 µM mM cm-2 at low glucose concentration (3-500 µM) and 29.52 µA mM cm-2 at high glucose concentration (700-4000 µM), achieving a low detection limit of 1.1 µM (S/N = 3). The sensor also demonstrates enhanced selectivity and stability for detecting glucose. Furthermore, the portable sensor exhibits a clear step-ampere response in the detection of serum samples with satisfactory recovery ranging from 99.30 to 101.32%. This suggests the significant potential of portable glucose sensing applications.

Fabrication of a Nanosized g-C3N4-Loaded Cellulose Microfiber Bundle to Induce Highly Efficient Water Treatment via Photodegradation .

Graphite carbon nitride (g-C3N4) with a suitable structure and strong amine activity is designed and prepared to serve as a hydrogen bond donor for the microfibrilization of corncob cellulose to form a cellulose microfiber (CMF) bundle. Simultaneously, well-dispersed nanosized g-C3N4 is loaded into the bundle to form a photocatalyst for efficient photodegradation of rhodamine B (Rh B) in water. Under the optimal preparation conditions at 165 °C, 10 min, and 0.08 mol/L H2SO4, the yield of g-C3N4-functionalized cellulose microfibers (CMF-g-C3N4) reaches to the highest over 70%. The catalytic rate of CMF-g-C3N4 is 3.3 times larger than that of pure g-C3N4. The degradation rate of Rh B is maintained at over 90% in 10 cycles of photocatalytic degradation. The obtained CMF-g-C3N4 also has good thermal stability and mechanical properties. This research suggests a particularly simple way to transform cellulose into a highly efficient photocatalyst for water treatment.

Kinetics of Lignin Separation during the Atmospheric Fractionation of Bagasse with p-Toluenesulfonic Acid.

As a green and efficient component separation technology, organic acid pretreatment has been widely studied in biomass refining. In particular, the efficient separation of lignin by p-toluenesulfonic acid (p-TsOH) pretreatment has been achieved. In this study, the mechanism of the atmospheric separation of bagasse lignin with p-TsOH was investigated. The separation kinetics of lignin was analyzed. A non-simple linear relationship was found between the separation yield of lignin and the concentration of p-TsOH, the temperature and the stirring speed. The shrinking nucleus model for the separation of lignin was established based on the introduction of mass transfer and diffusion factors. A general model of the total delignification rate was obtained. The results showed that the process of lignin separation occurred into two phases, i.e., a fast stage and a slow stage. The results provide a theoretical basis for the efficient separation of lignin by p-TsOH pretreatment.

Effect of temperature on simultaneous separation and extraction of hemicellulose using p-toluenesulfonic acid treatment at atmospheric pressure.

Hemicelluloses were effectively separated using p-toluenesulfonic acid (p-TsOH) treatment at high temperature. High temperature and pressure promoted hydrolysis of hemicellulose, which limited its value upon recovery. In this study, bagasse hemicellulose was separated and extracted by p-TsOH treatment at atmospheric pressure. The effects of temperature, p-TsOH concentration, and time on hemicellulose separation and extraction were investigated. The optimal conditions were 80 °C, 3.0% p-TsOH, and 120 min. The separation and extraction yield of hemicellulose was 73.23% and 36.02%, respectively. Extraction hemicellulose with 95.60% purity was obtained. In addition, the dissolution mechanism of hemicellulose was analyzed. Degradation of ß-glycosidic bonds was inhibited. Benzyl ether bond between carbohydrates and lignin was selectively cleaved. The skeleton structure of xylan in hemicellulose was protected while the functional groups of branch chain were severely damaged. It provides a valuable theoretical basis for the efficient separation and extraction of hemicellulose.

Green, efficient extraction of bamboo hemicellulose using freeze-thaw assisted alkali treatment.

The premise of high value utilization of lignocellulosic biomass is effective separation of hemicellulose. In this paper, the extraction of bamboo hemicellulose using freeze-thaw assisted alkali treatment (FAT) was studied. The effect of alkali concentration, alkali treatment time, freezing temperature, and freeze-thaw time on the main components was studied. Bamboo was frozen at -30 °C for 12 h, thawed at room temperature, and then treated at 75 °C for 90 min with 7.0% alkali. The extraction rate of hemicellulose was as high as 64.71%. The purity of hemicellulose samples using conventional AT decreased from 82.63% to 78.56%. Hemicellulose with the same yield as that of conventional alkali treatment was obtained by further reducing the alkali concentration. The purity of hemicellulose samples increased from 82.63% to 89.45%. It had a higher purity, higher molecular weight, and lower polydispersity. A new, green and efficient alkaline extraction method for hemicellulose was developed.

Effect of p-TsOH pretreatment on separation of bagasse components and preparation of nanocellulose filaments.

The efficient separation of bagasse components was achieved by p-toluenesulfonic acid (p-TsOH) pretreatment. The effects of p-TsOH dosage, reaction temperature and reaction time on cellulose, hemicellulose and lignin contents were studied. Eighty-five per cent of lignin was dissolved, whereas the cellulose loss was minimal (less than 8.1%). Cellulose-rich water-insoluble residual solids were obtained. The degree of polymerization of cellulose decreased slightly, but the crystallinity index (CrI) increased from 52.0% to 68.1%. It indicated that the highly efficient delignification of bagasse was achieved by p-TsOH pretreatment. The nanocellulose filaments (CNFs) were produced by the treated samples. The physico-chemical properties of CNFs were characterized by transmission electron microscopy and thermogravimetric analysis. The results show that the CNFs have smaller average size and higher thermal stability. It provides a new method for CNFs.

Improving moisture barrier properties of paper sheets by cellulose stearoyl ester-based coatings.

As commonly-used packaging material, paper has very poor moisture barrier properties, which are essential for maintaining physical and mechanical performance of paper as well as the shelf life of the packed goods. Herein, solutions of the synthesized cellulose stearoyl ester (CSE) compound were coated onto the calendered paper sheets by bar coater with the coating grammage ranging from 0.5-23.6 g m-2. When the coating grammage was 5.2 g m-2, the paper surface was totally covered by the CSE film with very low surface roughness (2.327 nm). The resulting CSE-coated papers from this coating grammage showed decreased tensile index and increased elongation at break, indicating the flexibility of the coated papers. Furthermore, the coated paper sheets were hydrophobic and displayed competitive water vapor barrier properties with the barrier ratio up to 90 %. Thereby, the designed CSE-coated paper sheets are promising for moisture barrier packaging application.