ChemInform Abstract: A NEW ETCHING SOLUTION SYSTEM, PHOSPHORIC ACID-HYDROGEN PEROXIDE-WATER, FOR GALLIUM ARSENIDE AND ITS KINETICS

1978 ◽  
Vol 9 (49) ◽  
Author(s):  
Y. MORI ◽  
N. WATANABE
Keyword(s):  
Hydrogen Peroxide ◽  
Gallium Arsenide ◽  
Phosphoric Acid ◽  
Solution System ◽  
Etching Solution

scholarly journals Self-generated peroxyacetic acid in phosphoric acid plus hydrogen peroxide pretreatment mediated lignocellulose deconstruction and delignification

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Dong Tian ◽  
Yiyi Chen ◽  
Fei Shen ◽  
Maoyuan Luo ◽  
Mei Huang ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Acetic Acid ◽  
Synergistic Effect ◽  
Phosphoric Acid ◽  
Wheat Straw ◽  
Lignin Degradation ◽  
Acid Oxidation ◽  
Main Function ◽  
Corn Stalk ◽  
Peroxyacetic Acid

Abstract Background Peroxyacetic acid involved chemical pretreatment is effective in lignocellulose deconstruction and oxidation. However, these peroxyacetic acid are usually artificially added. Our previous work has shown that the newly developed PHP pretreatment (phosphoric acid plus hydrogen peroxide) is promising in lignocellulose biomass fractionation through an aggressive oxidation process, while the information about the synergistic effect between H3PO4 and H2O2 is quite lack, especially whether some strong oxidant intermediates is existed. In this work, we reported the PHP pretreatment system could self-generate peroxyacetic acid oxidant, which mediated the overall lignocellulose deconstruction, and hemicellulose/lignin degradation. Results The PHP pretreatment profile on wheat straw and corn stalk were investigated. The pathways/mechanisms of peroxyacetic acid mediated-PHP pretreatment were elucidated through tracing the structural changes of each component. Results showed that hemicellulose was almost completely solubilized and removed, corresponding to about 87.0% cellulose recovery with high digestibility. Rather high degrees of delignification of 83.5% and 90.0% were achieved for wheat straw and corn stalk, respectively, with the aid of peroxyacetic acid oxidation. A clearly positive correlation was found between the concentration of peroxyacetic acid and the extent of lignocellulose deconstruction. Peroxyacetic acid was mainly self-generated through H2O2 oxidation of acetic acid that was produced from hemicellulose deacetylation and lignin degradation. The self-generated peroxyacetic acid then further contributed to lignocellulose deconstruction and delignification. Conclusions The synergistic effect of H3PO4 and H2O2 in the PHP solvent system could efficiently deconstruct wheat straw and corn stalk lignocellulose through an oxidation-mediated process. The main function of H3PO4 was to deconstruct biomass recalcitrance and degrade hemicellulose through acid hydrolysis, while the function of H2O2 was to facilitate the formation of peroxyacetic acid. Peroxyacetic acid with stronger oxidation ability was generated through the reaction between H2O2 and acetic acid, which was released from xylan and lignin oxidation/degradation. This work elucidated the generation and function of peroxyacetic acid in the PHP pretreatment system, and also provide useful information to tailor peroxide-involved pretreatment routes, especially at acidic conditions. Graphical abstract

Etching Volume Effect on the Morphology of Silicon Etched by Metal-Assisted Chemical Method

2012 ◽  
Vol 217-219 ◽  
pp. 1141-1145 ◽  
Author(s):  
Wei Wang ◽  
Li Juan Zhao ◽  
Ping Xin Song ◽  
Ying Jiu Zhang
Keyword(s):  
Hydrogen Peroxide ◽  
Aqueous Solutions ◽  
Formation Mechanism ◽  
Ag Nanoparticles ◽  
Hydrofluoric Acid ◽  
Chemical Method ◽  
Volume Effect ◽  
Etching Solution ◽  
Si Substrates ◽  
Si Nanostructures

Assisted by Ag nanoparticles, Si substrates were etched in aqueous solutions containing hydrofluoric acid (HF) and hydrogen peroxide (H2O2) with different volumes of etching solution. The etching morphology of Si wafers was found to be affected by the volumes. In etching solutions with smaller volume, the pores were created; in etching solutions with larger volume, the nanostructure composed of nanowires and nanopores (pores+wires nanostructure) were generated. In addition, the lengths of these Si nanostructures increased with the increase of the etching volume. Possible formation mechanism for this phenomenon was discussed.

Recycling solvent system in phosphoric acid plus hydrogen peroxide pretreatment towards a more sustainable lignocellulose biorefinery for bioethanol

2019 ◽  
Vol 275 ◽  
pp. 19-26 ◽  
Author(s):  
Fengpei Yao ◽  
Dong Tian ◽  
Fei Shen ◽  
Jinguang Hu ◽  
Yongmei Zeng ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Phosphoric Acid ◽  
Solvent System

scholarly journals Valorizing Waste Lignocellulose-Based Furniture Boards by Phosphoric Acid and Hydrogen Peroxide (Php) Pretreatment for Bioethanol Production and High-Value Lignin Recovery

2019 ◽  
Vol 11 (21) ◽  
pp. 6175
Author(s):  
Jingwen Zhao ◽  
Dong Tian ◽  
Fei Shen ◽  
Jinguang Hu ◽  
Yongmei Zeng ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Phosphoric Acid ◽  
Water Retention ◽  
Water Retention Capacity ◽  
Retention Capacity ◽  
Fractionation Process ◽  
Oh Groups ◽  
Lignin Recovery ◽  
High Cellulose ◽  
Simultaneous Saccharification

Three typical waste furniture boards (fiberboard, chipboard, and blockboard) were pretreated with phosphoric acid and hydrogen peroxide (PHP). The fractionation process of these feedstocks was attempted in order to harvest the cellulose-rich fraction for enzymatic hydrolysis and bioethanol conversion; further, lignin recovery was also considered in this process. The results indicated that 78.9–91.2% of the cellulose was recovered in the cellulose-rich fraction. The decreased crystallinity, which promoted the water retention capacity and enzyme accessibility, contributed greatly to the excellent hydrolysis performance of the cellulose-rich fraction. Therefore, rather high cellulose–glucose conversions of 83.3–98.0% were achieved by hydrolyzing the pretreated furniture boards, which allowed for harvesting 208–241 g of glucose from 1.0 kg of feedstocks. Correspondingly, 8.1–10.4 g/L of ethanol were obtained after 120 h of simultaneous saccharification and fermentation. The harvested lignin exhibited abundant carboxyl –OH groups (0.61–0.67 mmol g−1). In addition, approximately 15–26 g of harvested oligosaccharides were integrated during PHP pretreatment. It was shown that PHP pretreatment is feasible for these highly recalcitrant biomass board materials, which can diversify the bioproducts used in the integrated biorefinery concept.

Effect of complexing agents on desulphurization and deashing of coal by H2O2/H2SO4 leaching

2018 ◽  
Vol 29 (7) ◽  
pp. 1142-1154
Author(s):  
Hafiza Sana ◽  
Rizwan Haider ◽  
Muhammad Usman Rahim ◽  
Shahid Munir
Keyword(s):  
Hydrogen Peroxide ◽  
Citric Acid ◽  
Phosphoric Acid ◽  
Removal Efficiency ◽  
Coal Sample ◽  
Complexing Agents ◽  
Complexing Agent ◽  
Chemical Leaching ◽  
Optimized Conditions

The present study was aimed at investigating the effect of the addition of complexing agents on the removal efficiency of sulphur and ash contents during chemical leaching by acidified hydrogen peroxide. Representative coal sample from Lakhra was subjected to chemical leaching under various conditions of the parameters including time (60 and 120 min), temperature (25 and 50°C), complexing agents (citric acid and phosphoric acid) and the concentration of complexing agents (100 and 1000 ppm). The addition of complexing agents, i.e. citric acid and phosphoric acid imparted significant effects on improving the removal efficiency of sulphur and ash contents. Under optimized conditions, it was found out that the addition of citric acid improved the removal efficiency for sulphur from 63.88 to 83.47% and from 33.12 to 66.25% for ash. In case of phosphoric acid, the removal in sulphur and ash contents was increased from 63.77 to 80.77% and from 33.12 to 59.18%, respectively. Apparently, citric acid happened to be the most effective complexing agent, as compared to phosphoric acid. These results warrant subsequent detailed studies for further optimization of the process, including the use of some other complexing agents, as well.

scholarly journals Pretreatment of Wheat Straw with Phosphoric Acid and Hydrogen Peroxide to Simultaneously Facilitate Cellulose Digestibility and Modify Lignin as Adsorbents

Biomolecules ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 844 ◽  
Author(s):  
Xue Wan ◽  
Fengpei Yao ◽  
Dong Tian ◽  
Fei Shen ◽  
Jinguang Hu ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Regression Analysis ◽  
Phosphoric Acid ◽  
Wheat Straw ◽  
Oxidative Modification ◽  
Integrated Process ◽  
Lignin Valorization ◽  
Lignin Modification ◽  
Adsorption Capacities ◽  
Cellulose Digestibility

Effective valorization of lignin is crucial to achieve a sustainable, economic and competitive biorefinery of lignocellulosic biomass. In this work, an integrated process was proposed based on a concentrated phosphoric acid plus hydrogen peroxide (PHP) pretreatment to simultaneously facilitate cellulose digestibility and modify lignin as adsorbent. As a dominant constitutor of PHP pretreatment, H2O2 input and its influence on the overall fractionation/lignin modification performance was thoroughly investigated. Results indicated that wheat straw was fractionated more efficiently by increasing the H2O2 input. H2O2 input had a significant influence on the digestibility of the obtained cellulose-rich fraction whereby almost 100.0% cellulose-glucose conversion can be achieved even with only 0.88% H2O2 input. Besides, the adsorption capacity of lignin on MB was improved (74.3 to 210.1 mg g−1) due to the oxidative-modification in PHP pretreatment with H2O2 inputs. Regression analysis indicated that –COOH groups mainly governed the lignin adsorption (R2 = 0.946), which displayed the considerable adsorption capacities for typical cationic substances. This work shows a promising way to integrate the lignin modification concept into the emerging PHP pretreatment process with the dual goal of both cellulose utilization and lignin valorization.

Adhesive Bonding of Various Materials to Hard Tooth Tissues. XIV. Enamel Mordant Selection Assisted by ESCA (XPS)

1978 ◽  
Vol 57 (4) ◽  
pp. 551-556 ◽  
Author(s):  
R.L. Bowen
Keyword(s):  
Chemical Analysis ◽  
Phosphoric Acid ◽  
Surface Analysis ◽  
Photoelectron Spectroscopy ◽  
Electron Spectroscopy ◽  
Adhesive Bonding ◽  
Acid Etching ◽  
Etching Solution ◽  
X Ray

Surface analysis by XPS (X-ray photoelectron spectroscopy), also called ESCA (electron spectroscopy for chemical analysis), indicates that only certain cations are appreciably sorbed by enamel from an acid etching solution containing phosphoric acid and equimolar concentrations of candidate mordant salts.

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