hydrolysis method
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2021 ◽  
pp. 75-82
Author(s):  
Saida Bokizhonovna Khaytmetova ◽  
Abbaskhan Sabirkhanovich Turaev ◽  
Bakhtiyor Ikromovich Muhitdinov ◽  
Gulnoza Abduvahabovna Khalilova

Obtaining and studying the functional properties and determining the subsequent purpose in the practical use of pectin substances requires a thorough study of physical and chemical characteristics of the polysaccharide. By using the acidic hydrolysis method, pectic polysaccharides were isolated from nonconventional raw materials of natural origins - basidial fungus mushrooms Fomes fomentarius, Ganoderma lucidum, Inonotus hispidus, Polýporus squamosus. The polysaccharides isolated were characterized: such as content of free and etherifying carboxyl groups, total -СООН groups, -ОСН3 groups, degree of etherification and by data of the IR-spectroscopy. The pectic polysaccharides isolated in identical conditions from the basidial mushrooms were powders with colors from light yellow to is light-brown by the appearance, possess sub-acidic taste, have no extraneous smack and a smell. The pectin from Inonotus hispidus was much lighter than other pectins (Fomes fomentarius, Ganoderma lucidum, Polýporus squamosus). The pectin’s isolated were similar to the apple pectin by the organoleptic properties. They can classified as averagely etherified pectins regarding the degree etherification. Etherification degree of the studied pectins was in the range of 50.00–66.67%. The methoxyl groups were ranged between 8.47–11.43%. Content of free carboxylic groups in the range of 2.25–5.40%.


Author(s):  
Du Yuan ◽  
Hao Liu ◽  
Zixuan Wang ◽  
Xi Wang ◽  
Guirong Miao ◽  
...  

Abstract β-PbO2 is an important high oxygen overpotential anode coating material. Further study on nanoscale β-PbO2 with higher performance and lower cost is a critical issue in order to develop the electrochemical ozone generator. Herein, an improved β-PbO2 nanoparticles synthesizing strategy based on the traditional Pb(OAc)4 hydrolysis method is proposed in this work, which is more scalable for industrial-scale production compared with existed nano β-PbO2 synthesizing methods. The possible mechanism of synthesizing β-PbO2 nanoparticles via Pb(OAc)4 hydrolysis was discussed for the first time. Based on the proposed mechanism, the size and morphology of the β-PbO2 nanoparticles were effectively controlled, and alternative raw material that can significantly reduce costs was developed. SEM, TEM, XRD, and XPS results indicate that pure phase β-PbO2 nanoparticles range from 10-30 nm were obtained. In addition, the use of alternative raw materials reduces the cost by 90%-95% compared to the traditional Pb(OAc)4 hydrolysis method. The β-PbO2 nanoparticles showed good ozone generation performances. The energy consumption per unit ozone of the β-PbO2 nanoparticles is reduced by 51.9% at the optimized operation condition than the reference PbO2 particles used for comparis


2021 ◽  
Vol 9 ◽  
Author(s):  
Mingxuan Guo ◽  
Haibo Li

In this work, Mil-88B(Fe) is modified by a facile hydrolysis method for high-performance lithium ion battery (LIB). The hydrolyzed Mil-88B(Fe) [H-Mil-88B(Fe)] heritages the spindle-like shape of Mil-88B(Fe) and forms a porous structure, which possesses relatively high specific surface area (427.86 m2 g−1). It is 15 times higher than that of pristine Mil-88B(Fe). As anode for LIB, it reaches to high specific capacity of 600.1 mAh g−1 after 100 cycles at 100 mA g−1, while it is 312.5 mAh g−1 for pure Mil-88B(Fe). Furthermore, the kinetic analysis on i=avb reveals that the b value of H-Mil-88B(Fe) is 0.888, which suggests the mixed contribution from the diffusion and capacity reactions. Furthermore, the capacitance contribution fractions of H-Mil-88B(Fe) are 47.6%, 53.28%, 56.88%, 74.68%, and 69.14% at the sweep rate of 0.2, 0.4, 0.6, 0.8, 1.0 mV s−1, respectively, demonstrating a capacitance-dominated charge storage process at fast charging rates.


2021 ◽  
Vol 924 (1) ◽  
pp. 012031
Author(s):  
A R Pramitha ◽  
H Harijono ◽  
S N Wulan

Abstract Arbila beans contains cyanogenic compounds in the form of linamarin (cyanoglucosides), acetone cyanohydrin, and free cyanide, all together constitute total cyanide content. The objective of this study was to compare the cyanide content in arbila beans analyzed by picrate and acid hydrolysis methods. Picrate method measures total cyanide only. Cyanide content was identified by using a picrate paper, which turned into yellow. The absorbance was measured by a spectrophotometer at 510 nm. Acid hydrolysis method measures cyanide in arbila beans in the form of linamarin, acetone cyanohydrin, and free cyanide. Linamarin wa hydrolyzed in H3PO4 solution. Estimated cyanide levels was measured by using a colorimetric procedure. Data was analyzed using Independent sample t-test (SPSS v.16). The results showed that, there was no difference in the total level of cyanide in both methods. Total cyanide measured by picrate and acid hydrolysis method was 2705.17 ppm and 2693.29 ppm, respectively. In addition, the three forms of cyanide content were as follows: linamarin 926.22 ppm, cyanohydrin 556.01 ppm, and free cyanide 1211.06 ppm. Based on the results, both methods can be used for total cyanide analysis. To determine the form of cyanide other than total cyanide, it is recommended to use the acid hydrolysis method.


2021 ◽  
Vol 898 (1) ◽  
pp. 012022
Author(s):  
Qinnan Yin ◽  
Huixin Jin ◽  
Fuzhong Wu ◽  
Weijie Wang ◽  
Qian Yang

Abstract High-purity alumina refers to ultra-fine alumina powder with a purity exceeding 99.99% and a uniform particle size. This material exhibits excellent corrosion resistance, high-temperature resistance, wear resistance, and oxidation resistance. Owing to the high silicon content of alumina prepared by means of the alcohol-aluminum hydrolysis method, the purity of the alumina is often unsatisfactory. Therefore, in this work, a new method for adding lanthanum oxide to isopropanol in the early aluminum isopropoxide synthesis stage is proposed. When lanthanum oxide was added, the silicon content of the precursor aluminum isopropoxide decreased to 0.0051%.Remove calcium, sodium, magnesium and other impurities by cleaning with hydrochloric acid under an ultrasonic field. The optimal hydrolysis conditions were determined as follows: hydrolysis temperature: 55, hydrolysate concentration: 80%, water to alkoxide ratio: 6:1. The alumina precursor calcined at 1200 yielded a high-purity alumina with a purity level of more than 99.99%, and the particle size reaches 2.037 μm.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Qibo Zhang ◽  
Lu Cheng ◽  
Xutong Ma ◽  
Xin Zhou ◽  
Yong Xu

Abstract Background Sunflower stalk pith, residue from the processing of sunflower, is rich in pectin and cellulose, thereby acting as an economic raw material for the acquisition of these compounds. In order to increase the commercial value of sunflower processing industry, a two-step dilute sulfuric acid treatment process was conducted on spent sunflower stalk pith to obtain the value-added products, pectin and glucose. Results In this study, pectin was firstly extracted under mild acid condition to avoid pectin degradation, which was conducted at 90 °C with a pH of 2.0 for 2 h, and ~0.14 g/g of pectin could be recovered. Then the remaining solids after pectin extraction were subjected to the reinforced treatment process with 0.75% H2SO4 at 150 °C for 30 min to further improve enzymatic hydrolysis efficiency. Moreover, by combining a fed-batch enzymatic hydrolysis strategy, a solid loading content of 16% was successfully achieved and the glucose titer reached 103.1 g/L with a yield of 83.6%. Conclusion Finally, ~140 g pectin and 260 g glucose were produced from 1 kg of raw sunflower stalk pith using the integrated biorefinery process. This work puts forward a two-step dilute acid pretreatment combined with enzymatic hydrolysis method to produce pectin and glucose from sunflower spent waste.


2021 ◽  
Author(s):  
Zahra Hassankhani-Majd ◽  
Mansoor Anbia

Abstract Nanoporous materials have been widely used in many fields. However, their synthesis with uniform particle shapes, pore sizes, pore volumes, and surface areas remains a considerable challenge. Thus, choosing a suitable controllable method for synthesizing nanoporous materials is crucial to obtain appropriate properties. Herein, nanoporous titania particles (NPTPs) were prepared via the hydrothermal. This study investigated how the synthesis parameters such as the type of chelating agent, the hydrolysis method, and the drying technique affected the properties of NPTPs. The synthesis NPTPs were characterized by XRD, FESEM, and BET. The results demonstrated that when acetylacetone (ACAC) (as the chelating agent), the spray-hydrolysis (SH) method, and the freeze-drying (FD) technique were used, NPTPs achieved a more uniform particle shape, a smaller particle size, a larger pore size, a larger pore volume, and a higher surface area. Ultimately, the photocatalytic degradation (PCD) of methylene blue (MB) was examined using improved NPTPs.


2021 ◽  
Author(s):  
Banza Musamba ◽  
Hilary Rutto

Abstract Cellulose nanocrystals (CNCs) have unique and diverse applications in the various fields of developing nanomaterials. In this work, cellulose nanocrystals were extracted from millet husk residue waste using a homogenized acid hydrolysis method. The effects of the process variables namely; homogenization speed, acid concentration and acid to cellulose ratio on the yield and swelling capacity were investigated and optimized using the Box Behnken design method in response surface methodology. The cellulose and nano-cellulose obtained were characterized using transform infrared microscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). The numerical optimization analysis results showed that the maximum yield of CNCs from cellulose was 93.12 % and obtained at homogenization speed, acid concentration, and acid to cellulose ratio of 7464.0 rpm, 63.40 wt %, and 18.83 wt % respectively. The maximum swelling capacity of 2.81 % was obtained at homogenization speed, acid concentration, and acid to cellulose ratio of 8000 rpm, 62.5 wt %, and 25 wt % respectively. A mathematical model was obtained to predict the yield and the swelling capacity of cellulose nanocrystals with R2 of the value of 98.9 % and 97.9% respectively. The TGA showed that the thermal stability of cellulose was higher than that of CNCs, FTIR results showed functional groups of CNCs and cellulose were similar, SEM image of CNCs is porous and displayed narrow particle size and needle-like morphology as compared to cellulose and XRD pattern presented an increase in the intensity of CNCs.


2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Hang Wu ◽  
Qi Jiang ◽  
Keyi Luo ◽  
Chunping Zhu ◽  
Mengmeng Xie ◽  
...  

AbstractThe combination of photothermal therapy (PTT) and photodynamic therapy (PDT) has attracted attention due to its enhanced tumor therapy effect. This study proposes a novel nanoenzyme-based theranostic nanoplatform, IrO2@MSN@PDA-BSA(Ce6), for the combined PTT and PDT of tumors. IrO2 was prepared by a simple hydrolysis method and coated with a thin layer of mesoporous silica (MSN) to facilitate the physical adsorption of Chlorin e6 (Ce6). The PDA coating and IrO2 NPs of the nanoplatform demonstrated an improved photothermal conversion efficiency of 29.8% under NIR irradiation. Further, the Ce6 loading imparts materials with the ability to produce reactive oxygen species (ROS) under 660 nm NIR laser irradiation. It was also proved that the IrO2 NPs could catalyze the hydrogen peroxide (H2O2) in the tumor microenvironment (TME) to generate endogenous oxygen (O2), thereby enhancing the efficiency of PDT. The in vitro and in vivo experiments indicated that the nanocomposite was highly biocompatible and could produce a satisfactory tumor therapeutic effect. Thus, the findings of the present study demonstrate the viability of using theranostic nanoenzymes for translational medicine.


2021 ◽  
Vol 415 ◽  
pp. 129044
Author(s):  
Yu Sun ◽  
Qiao Wang ◽  
Zhibin Geng ◽  
Zhongyuan Liu ◽  
Rusen Yang

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