scholarly journals Optimization of cellulose nanocrystal length and surface charge density through phosphoric acid hydrolysis

2017 ◽  
Vol 376 (2112) ◽  
pp. 20170041 ◽  
Author(s):  
Oriana M. Vanderfleet ◽  
Daniel A. Osorio ◽  
Emily D. Cranston
Keyword(s):  
Thermal Stability ◽  
Sulfuric Acid ◽  
Phosphoric Acid ◽  
Charge Density ◽  
Acid Hydrolysis ◽  
Acid Concentration ◽  
Large Range ◽  
Phosphate Content ◽  
Hydrolysis Temperature ◽  
Phosphoric Acid Hydrolysis

Cellulose nanocrystals (CNCs) are emerging nanomaterials with a large range of potential applications. CNCs are typically produced through acid hydrolysis with sulfuric acid; however, phosphoric acid has the advantage of generating CNCs with higher thermal stability. This paper presents a design of experiments approach to optimize the hydrolysis of CNCs from cotton with phosphoric acid. Hydrolysis time, temperature and acid concentration were varied across nine experiments and a linear least-squares regression analysis was applied to understand the effects of these parameters on CNC properties. In all but one case, rod-shaped nanoparticles with a high degree of crystallinity and thermal stability were produced. A statistical model was generated to predict CNC length, and trends in phosphate content and zeta potential were elucidated. The CNC length could be tuned over a relatively large range (238–475 nm) and the polydispersity could be narrowed most effectively by increasing the hydrolysis temperature and acid concentration. The CNC phosphate content was most affected by hydrolysis temperature and time; however, the charge density and colloidal stability were considered low compared with sulfuric acid hydrolysed CNCs. This study provides insight into weak acid hydrolysis and proposes ‘design rules’ for CNCs with improved size uniformity and charge density. This article is part of a discussion meeting issue ‘New horizons for cellulose nanotechnology’.

scholarly journals The Effect of Electronic Medical Record Adaptation on Reported Medication Errors in Peripartum Care Areas

2017 ◽  
Vol 1 (1) ◽  
Keyword(s):  
Sulfuric Acid ◽  
Acid Concentration ◽  
Cellulose Hydrolysis ◽  
Colloidal Dispersions ◽  
Degree Of Polymerization ◽  
Degree Of Crystallinity ◽  
Minimum Level ◽  
Hydrolysis Temperature ◽  
Hydrolysis Conditions ◽  
Negative Zeta Potential

Relationship between concentration of sulfuric acid (C) and temperature (T) required for the cellulose hydrolysis to prepare nanocrystalline cellulose particles (NCP has been studied in this paper. The experiments showed that there is a linear C and T superposition exists, namely: C= Co - n T. The higher the acid concentration, the lower the hydrolysis temperature should be used, and vice versa. The minimum level of acid concentration that can be used for production of CNP is 40 wt. % at optimal temperature of 80o C. If temperature or acid concentration is lower, there is a tendency to form of microparticles. On the other hand, at higher hydrolysis temperatures, carbonized CNP with decreased yield are obtained. The rod-like crystalline nanoparticles of cellulose produced at optimal hydrolysis conditions (C=40 wt. %, T=80o C) have average sizes of 150 x 15 nm, degree of crystallinity of 75- 77% and degree of polymerization of 130-150. The nanoparticles form stable colloidal dispersions in water due to Brownian motion and negative Zeta potential imparting to these particles the mutual electrostatic repulsion. Estimated calculations have also shown that decrease in the concentration of sulfuric acid from 60 to 40 wt. % at production of CNP is economically advantageous despite increase in hydrolysis temperature from 45 to 80o C.

scholarly journals Influence of Hydrolysis Conditions on Characteristics of Nanocrystalline Cellulose Extracted from Ramie Fibers by Hydrochloric Acid Hydrolysis

2020 ◽  
Author(s):  
Kusmono Kusmono ◽  
Dimas Abdillah Akbar
Keyword(s):  
Thermal Stability ◽  
Hydrochloric Acid ◽  
Acid Hydrolysis ◽  
Acid Concentration ◽  
Crystallinity Index ◽  
Hydrochloric Acid Concentration ◽  
Hydrolysis Time ◽  
Study Results ◽  
Ramie Fibers ◽  
Hydrolysis Conditions

Abstract Nanocrystalline celluloses (NCCs) were successfully extracted from ramie fibers using chemical pretreatments followed by hydrochloric acid hydrolysis. The effects of acid concentration and hydrolysis time on the characteristics of NCCs were investigated in this study. Results showed that the optimal hydrolysis conditions were found to be 6 M hydrochloric acid concentration at 45 °C for 70 min. The obtained NCC had a rod like-shape with an average of 8.07 nm in diameter, 158.51 nm in length, 22.37 in aspect ratio, 89.61% in the crystallinity index, and 5.81 nm in crystallite size. The higher crystallinity and thermal stability were exhibited by NCCs compared to both raw fibers and chemically purified cellulose. The hydrolysis time had a significant effect on crystallinity and thermal stability. The crystallinity index and thermal stability of NCCs were obtained to decrease with increasing hydrolysis time.

The phosphoric acid hydrolysis of 4-aminobenzo [b] thiophene

1970 ◽  
Vol 11 (60) ◽  
pp. 5265-5266 ◽  
Author(s):  
Donald E. Boswell ◽  
James A. Brennan ◽  
Phillip S. Landis
Keyword(s):  
Phosphoric Acid ◽  
Acid Hydrolysis ◽  
Phosphoric Acid Hydrolysis ◽  
Hydrolysis Of

scholarly journals Ammonia recovery from human urine as liquid fertilizers in hollow fiber membrane contactor: Effects of permeate chemistry

2020 ◽  
Vol 26 (1) ◽  
Author(s):  
Mekdimu Mezemir Damtie ◽  
Federico Volpin ◽  
Minwei Yao ◽  
Leonard Demegilio Tijing ◽  
Ruth Habte Hailemariam ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Nitric Acid ◽  
Phosphoric Acid ◽  
Acid Concentration ◽  
Hollow Fiber ◽  
Human Urine ◽  
Hollow Fiber Membrane ◽  
Membrane Contactor ◽  
Fiber Membrane ◽  
Acid Type

The production of the existing nitrogen fertilizer is costly and less environmental-friendly. Various green technologies are currently emerging toward providing alternative options. In this study, a liquid/liquid hydrophobic hollow-fiber membrane contactor was employed at ambient temperature and natural urine pH ~ 9.7 to recover ammonium fertilizers from human urine. Results showed that permeate side chemistry was one of the major factors affecting the ammonia mass transfer. The study on the ammonia capturing performance of diluted sulfuric acid, phosphoric acid, nitric acid, and DI water confirmed that acid type, acid concentration, and permeate side operating pH were the most important parameters affecting the ammonia capturing tendency. Sulfuric acid was slightly better in capturing more ammonia than other acid types. The study also identified increasing acid concentration didn’t necessarily increase ammonia mining tendency because there was always one optimum concentration value at which maximum ammonia extraction was possible. The best permeate side operating pH to extract ammonia for fertilizer purposes was selected based on the dissociation equilibrium of different types of acids. Accordingly, the analysis showed that the membrane process has to be operated at pH > 3 for sulfuric acid, between 3.5 to 11.5 for phosphoric acid, and above 0.5 for nitric acid so as to produce their respective high-quality liquid ammonium sulfate, ammonium monophosphate/diphosphate, and ammonium nitrate fertilizer. Therefore, permeate side acid concentration, pH, and acid type has to always be critically optimized before starting the ammonia mining experiment.

scholarly journals Conversion of hemicellulose from kenaf core fiber to xylose through dilute sulfuric acid hydrolysis

2019 ◽  
Vol 21 (1) ◽  
pp. 14-22 ◽  
Author(s):  
William Judiawan ◽  
Yanni Sudiyani ◽  
Elda Nurnasari
Keyword(s):  
Sulfuric Acid ◽  
Acid Hydrolysis ◽  
Acid Concentration ◽  
Sulfuric Acid Concentration ◽  
Heating Time ◽  
Hibiscus Cannabinus ◽  
Kenaf Core ◽  
Dilute Sulfuric Acid ◽  
Acid Ratio ◽  
Xylose Concentration

Kenaf (Hibiscus cannabinus) is a lignocellulosic plant that is usually utilized as a fiber source for sack production. The core from kenaf fiber has not been utilized yet in Indonesia, therefore it is still considered as a waste. Hemicellulose from kenaf core can be hydrolyzed to xylose through dilute sulfuric acid hydrolysis in high temperature. Hydrolysis in this study was done by using autoclave at 121℃ and 10% (m/v) biomass: acid ratio for 15 and 45 minutes with a variation on acid concentration (2%, 4%, and 6% v/v). Xylose concentration in the hydrolyzate tends to increase with higher acid concentration and longer heating time. 6% (v/v) sulfuric acid concentration and 45 minutes of heating time produce the highest xylose concentration (20.53 gr/L) and yield (86.50%)

Study on Sugar Production Conditions of Dilute Sulfuric Acid Hydrolysis of Corn Straw

2014 ◽  
Vol 1008-1009 ◽  
pp. 97-100
Author(s):  
Qing Sun ◽  
Shu He Huang ◽  
Bo Wang ◽  
Xiao Run Deng ◽  
Jia Sheng Yi ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Reaction Time ◽  
Acid Hydrolysis ◽  
Acid Concentration ◽  
Sulfuric Acid Concentration ◽  
Sugar Yield ◽  
Corn Straw ◽  
Experimental Conditions ◽  
Dilute Sulfuric Acid ◽  
Hydrolysis Of

In this paper, through the study of reducing sugar conditions of corn straw hydrolysis under acidic condition, looking for the production of experimental conditions relatively reasonable. Mainly by dilute sulfuric acid hydrolysis of corn straw by single factor test, effects of sulfuric acid concentration, temperature, reaction time, particle size, ratio of solid to liquid five factors, effects on sugar yield of corn straw. The dilute sulfuric acid concentration 5%, ratio of solid to liquid was 1:14, when the reaction time is 140 min, particle fineness of 120 mesh, the reaction temperature is 100 °C, corn stalk sugar yield reached a maximum 20.11%.

Urea-Phosphoric Acid Hydrolysis of Cotton Modified with N-Methylolated Ethylene Ureas

1974 ◽  
Vol 44 (9) ◽  
pp. 670-679 ◽  
Author(s):  
H.Z. Jung ◽  
R.R. Benerito ◽  
E.J. Gonzales ◽  
R.J. Berni
Keyword(s):  
Phosphoric Acid ◽  
Acid Hydrolysis ◽  
Phosphoric Acid Hydrolysis ◽  
Hydrolysis Of

Study on the Hydrolysis of Corn Stalk and Photosynthetic Bacteria Group Fermentation Hydrogen Production

2011 ◽  
Vol 194-196 ◽  
pp. 2187-2190
Author(s):  
Bao Chen Cui ◽  
Guo Xin Zhang ◽  
Bo Hou ◽  
Jing Yan Zhao ◽  
Rui Li
Keyword(s):  
Sulfuric Acid ◽  
Hydrogen Production ◽  
Acid Concentration ◽  
Photosynthetic Bacteria ◽  
Sulfuric Acid Concentration ◽  
Optimum Process ◽  
Process Conditions ◽  
Hydrogen Yield ◽  
Corn Stalk ◽  
Hydrolysis Temperature

Hydrogen production of photosynthetic bacteria group (PSBG) was studied using corn stalk hydrolyzate as hydrogen production substrate. The effects of sulfuric acid concentration, hydrolysis pH values and hydrolysis temperature on hydrogen production were investigated. The optimum process conditions were as follows: the sulfuric acid concentration was 1%, hydrolysis pH value was 6.0 and the hydrolysis temperature was 110°C , respectively. Three hydrolyzate detoxification methods were compared. The method of calcium hydroxide obtained the optimal detoxification effect and the maximum hydrogen yield was 472 mL H2/ (L-medium).

Isolation of Thermally Stable Cellulose Nanocrystals by Phosphoric Acid Hydrolysis

2013 ◽  
Vol 14 (4) ◽  
pp. 1223-1230 ◽  
Author(s):  
Sandra Camarero Espinosa ◽  
Tobias Kuhnt ◽  
E. Johan Foster ◽  
Christoph Weder
Keyword(s):  
Phosphoric Acid ◽  
Acid Hydrolysis ◽  
Cellulose Nanocrystals ◽  
Thermally Stable ◽  
Phosphoric Acid Hydrolysis
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