scholarly journals Synthesis of Cellulose Nanocrystals (CNCs) from Brewer’s Spent Grain Using Acid Hydrolysis: Characterization and Optimization

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Bisrat Yihun Matebie ◽  
Belachew Zegale Tizazu ◽  
Aseel A. Kadhem ◽  
S. Venkatesa Prabhu
Keyword(s):  
Acid Hydrolysis ◽  
Acid Concentration ◽  
Cellulose Nanocrystals ◽  
Average Particle Size ◽  
Cellulose Nanocrystal ◽  
Average Particle ◽  
Hydrolysis Time ◽  
Solid Ratio ◽  
Spent Grain ◽  
Hydrolysis Conditions

This study is aimed at utilizing brewery’s spent grain (BSG) byproduct for the synthesis of cellulose nanocrystals (CNCs) using acid hydrolysis and optimizing the hydrolysis parameters (hydrolysis time, temperature, liquid-solid ratio, and acid concentration). Alkali and bleaching treatment were done to remove hemicellulose and lignin from BSG. Optimization process was performed using central composite design (CCD) to obtain optimum value of cellulose nanocrystal (CNC) yield. The maximum cellulose nanocrystal (CNC) yield of 43.24% was obtained at optimum hydrolysis conditions of 50°C, 51 wt% acid concentration, 41 min, and liquid-solid ratio of 19 ml/g. The raw brewery spent grain; alkali-treated fiber, bleached fiber, and obtained CNC were characterized using scanning electron microscopy (SEM), XRD, particle analyzer, FTIR, and differential scanning calorimeter (DSC). The characterization results indicated that the obtained cellulose nanocrystal (CNC) has rod-like whisker shape with crystallinity of 76.3% and an average particle size of 309.4 nm.

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 Role of Acid Concentration on Band Gap Shrinkage in Cellulose Nanocrystals Fabricated from Water Hyacinth

2022 ◽  
pp. 1-3
Author(s):  
Jack A Adem ◽  
◽  
John O Agumba ◽  
Godfrey O Barasa ◽  
Angeline A Ochung ◽  
...  
Keyword(s):  
Band Gap ◽  
Acid Concentration ◽  
Cellulose Nanocrystals ◽  
Optical Band Gap ◽  
Impurity Band ◽  
Band Gap Energy ◽  
Phase Identification ◽  
Hydrolysis Time ◽  
Gap Energy ◽  
Vis Spectroscopy

In this study, the fingerprint of the acid concentration during the hydrolysis process on the optical band gap of cellulose nanocrystals (CNCs) has been systematically studied. The CNCs have been prepared using hydrochloric acid at a hydrolysis temperature of 50°C and at a constant hydrolysis time of 4 hours but with varying hydrochloric cid concentrations of 5%, 10% and 15%. The crystalline structure and phase identification of the CNCs have been studied using XRD technique. UV-Vis Spectroscopy has been done and the optical band gap energy calculated by performing the Tauc’s plot. From the study, the grain size has been found to decrease with acid concentration while the band gap energy has been found to increase with increasing acid concentration. Further, the optical band gaps of the CNCs have been found to decrease with the increase in crystallite size. This shrinkage of the band gap has been attributed to the increased impurity concentration leading to the narrowing of the band gap due to the emerging of the impurity band formed by the overlapped impurity states

scholarly journals Optimization of the Obtaining of Cellulose Nanocrystals from Agave tequilana Weber Var. Azul Bagasse by Acid Hydrolysis

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 520
Author(s):  
Manuel Alberto Gallardo-Sánchez ◽  
Tania Diaz-Vidal ◽  
Alejandra Berenice Navarro-Hermosillo ◽  
Edgar Benjamin Figueroa-Ochoa ◽  
Rogelio Ramirez Casillas ◽  
...  
Keyword(s):  
Acid Concentration ◽  
Cellulose Nanocrystals ◽  
Photoelectron Spectroscopy ◽  
Agave Tequilana ◽  
Hydrolysis Time ◽  
X Ray ◽  
Force Microscopy ◽  
Acid Type ◽  
Size And Morphology ◽  
Total Sulfate

A multilevel factorial design of 23 with 12 experiments was developed for the preparation of cellulose nanocrystals (CNC) from Agave tequilana Weber var. Azul bagasse, an agro-industrial waste from tequila production. The studied parameters were acid type (H2SO4 and HCl), acid concentration (60 and 65 wt% for H2SO4, 2 and 8N for HCl) temperature (40 and 60 °C for H2SO4, 50 and 90 °C for HCl), and hydrolysis time (40, 55 and 70 min for H2SO4; and 30, 115 and 200 min for HCl). The obtained CNC were physical and chemically characterized using dynamic light scattering (DLS), atomic force microscopy (AFM), Fourier-transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XDR) techniques. The maximum CNC yield was 90 and 96% for HCL and H2SO4, respectively, and the crystallinity values ranged from 88–91%. The size and morphology of A. tequilana CNC strongly depends on the acid type and hydrolysis time. The shortest CNC obtained with H2SO4 (65 wt%, 40 °C, and 70 min) had a length of 137 ± 68 nm, width 33 ± 7 nm, and height 9.1 nm, whereas the shortest CNC obtained with HCl (2 N, 50 °C and 30 min) had a length of 216 ± 73 nm, width 69 ± 17 nm, and height 8.9 nm. In general, the obtained CNC had an ellipsoidal shape, whereas CNC prepared from H2SO4 were shorter and thinner than those obtained with HCl. The total sulfate group content of CNC obtained with H2SO4 increased with time, temperature, and acid concentration, exhibiting an exponential behavior of CSG=aebt.

scholarly journals Optimization of the Obtaining of Cellulose Nanocrystals from Agave Tequilana Weber Var. Azul Bagasse by Acid Hydrolysis

2021 ◽  
Author(s):  
Manuel Alberto Gallardo-Sánchez ◽  
Tania Diaz-Vidal ◽  
Alejandra Berenice Navarro-Hermosillo ◽  
Edgar Benjamín Figueroa Ochoa ◽  
Rogelio Ramirez Casillas ◽  
...  
Keyword(s):  
Acid Concentration ◽  
Cellulose Nanocrystals ◽  
Photoelectron Spectroscopy ◽  
Agave Tequilana ◽  
Hydrolysis Time ◽  
X Ray ◽  
Force Microscopy ◽  
Acid Type ◽  
Size And Morphology ◽  
Total Sulfate

A multilevel factorial design of 23 with 12 experiments was developed for the preparation of cellulose nanocrystals (CNC) from Agave tequilana Weber var. Azul bagasse. The studied parameters were acid type (H2SO4 and HCl), acid concentration (60 and 65 wt% for H2SO4, 2 and 8N for HCl) temperature (40 and 60°C for H2SO4, 50 and 90°C for HCl), and hydrolysis time (40, 55 and 70 min for H2SO4, 30, 115 and 200 min for HCl). The obtained CNC were physical and chemically characterized using dynamic light scattering (DLS), atomic force microscopy (AFM), Fourier-transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XDR) techniques. The size and morphology of A. tequilana CNC strongly depend on the acid type and hydrolysis parameters. The shortest CNC were obtained with H2SO4 (65 wt%, 40 °C, and 70 min) had a length of 137 ± 68 nm, width 33 ± 7 nm, and height 9.1 nm, whereas the shortest CNC obtained with HCl (2 N, 50 °C and 30 min) had a length of 216 ± 73 nm, width 69 ± 17 nm, and height 8.9 nm. CNC prepared from H2SO4 resulted shorter and thinner than those obtained with HCl. The total sulfate groups content in CNC obtained with H2SO4 increase with time agree to CSG=aebt, and increases with temperature and acid concentration.

Examination of YBa2Cu3O6+x precursor sol using 13C NMR Spectroscopy and Quasielastic Laser Light Scattering

1988 ◽  
Vol 121 ◽  
Author(s):  
S. Kramer ◽  
G. Moore ◽  
G. Kordas ◽  
P. A. Keifer ◽  
C. T.G. Knight
Keyword(s):  
Particle Size ◽  
Light Scattering ◽  
Colloidal Suspension ◽  
Average Particle Size ◽  
Scattering Data ◽  
Average Particle ◽  
Hydrolysis Time ◽  
Peak Broadening ◽  
Complexation Reactions ◽  
C Nmr

ABSTRACTThe structural evolution of YBa2Cu3O6+x precursor sol was investigated using 13C NMR and quasielastic light scattering. A polydisperse colloidal suspension of yttrium, barium and copper alkoxides was characterized as hydrolysis and complexation reactions occurred. Light scattering data showed that the average particle size of a copper(II) alkoxide suspension decreased by a factor of 5 (1100 nm to 220nm) with the addition of the yttrium and barium alkoxides over a period of 24 hours. The acquired particle size data correlated well with 13C NMR spectra, which showed initial peak broadening and the copper complexing to the yttrium and barium as a function of hydrolysis time.

scholarly journals Nanocellulose extraction and surface modification toward active packaging applications

2017 ◽  
Author(s):  
◽  
Ying Wu
Keyword(s):  
Surface Modification ◽  
Sulfuric Acid ◽  
Surface Charge ◽  
Acid Hydrolysis ◽  
Average Particle Size ◽  
Deep Eutectic Solvent ◽  
Dry Mass ◽  
Active Packaging ◽  
Average Particle ◽  
Hemicellulose Removal

Cellulose nanocrystals (CNCs) have attracted growing interest as a renewable nanomaterial. The main objective of this study was to explore the extraction of CNCs from switchgrass and surface modification of CNCs into antimicrobially active nanomaterials for active packaging application. Switchgrass was first fractionated via different pretreatment/pulping methods (i.e., acid-chlorite pretreatment, organosolv pretreatment, and deep eutectic solvent (DES) pretreatment), yielding high cellulose-enriched pulp (greater than 75.53 percent cellulose). Acid-chlorite pretreatment was the most effective for delignification, removing 97.80 percent lignin from switchgrass. In contrast, DES pretreatment was more effective for hemicellulose removal (greater than 79.55 percent xylan). Fourier transform infrared (FTIR) spectra also showed significant lignin and hemicellulose removal and enrichment of cellulose after pretreatment. Post-treatment with NaOH and H2O2 bleached organosolv and DES pulp, making them more suitable for CNCs extraction via sulfuric acid hydrolysis. The yields of CNCs extracted from the resulting pulps ranged from 30.52 to 35.82 percent (based on the dry mass of pulp loaded) via sulfuric acid hydrolysis with the highest yield observed with mildly post-treated ChCl: FA pulp. The surface charge of the prepared CNCs ranged from -20.30 to -26.70 mV. And the average particle size ranged from 63.55 to 222.20 nm. Surface modification by grafting polyethyleneimine (PEI) onto the surface of CNCs with carboxylic groups endowed CNCs with antimicrobial activity, especially toward Gram-positive bacteria Bacillus megaterium. The modified CNCs (CNCs-PEI) showed positive surface charge, indicating successful cationization. FTIR also confirmed the presence of PEI on surface modified CNCs. Incorporation of CNCs-PEI by 5 percent into PVA film improved its mechanical strength remarkably. This study demonstrated successful extraction of CNCs from switchgrass and development of antimicrobially active CNCs via surface modification toward active packaging applications. Antimicrobially active CNCs have great potential to be used as a multifunctional nanomaterial for advanced applications.

scholarly journals Preparation and Characterization of Nanocrystalline Cellulose from Cassava Stem Wastes by Electromagnetic Induction

2021 ◽  
Vol 16 (2) ◽  
pp. 109-117
Author(s):  
Lia Lismeri ◽  
Hertantri Yulia Rahmi ◽  
Nada Afifah Gomiyati ◽  
Yuli Darni ◽  
Panca Nugrahini Febriningrum ◽  
...  
Keyword(s):  
Acid Hydrolysis ◽  
Electromagnetic Induction ◽  
Average Particle Size ◽  
Nanocrystalline Cellulose ◽  
Raw Material ◽  
Induction Treatment ◽  
Average Particle ◽  
Cellulose Content ◽  
Naoh Solution ◽  
Cassava Stem

Cassava stems were one of the largest agricultural by products in Indonesia, especially in Lampung Province. It is known that cassava stems have a fairly high lignocellulose content, especially cellulose which reaches 39.29%. The high cellulose content in cassava stems has great potential to be used as raw material for Nanocrystalline Cellulose (NCC). The preparation of nanocrystalline cellulose consists of four main stages, namely: pre-hydrolysis, delignification, bleaching, and acid hydrolysis. The pre-hydrolysis stage was carried out by boiling a solution of CH3COOH and cassava stem powder for 60 minutes at a temperature of 105oC. Cassava stem powder was then delignified using a 25% NaOH solution heated to a temperature of 105oC for 1 hour. The bleaching stage used a 3.5% NaOCl solution at a temperature of 50oC for 60 minutes and was carried out twice. The last step is acid hydrolysis using 2.5N HCl solution for 15 minutes at a temperature of 105oC, then the electromagnetic induction treatment is varied with temperature variations of 30oC, 50oC, and 70oC for 60 minutes. The prepared nanocrystalline cellulose were tested for lignocellulose, XRD and PSA. From the test results, the best variation of nanocrystal cellulose preparation was acid hydrolysis treatment with 70oC electromagnetic induction for 60 minutes, namely an increase in the percentage of cellulose 62.93%, crystallinity 90.68%, and an average particle size of 18.04µm with some particles measuring nanometers. From the results of the research, it was concluded that electromagnetic induction increased crystallinity and decreased the size of nanocrystalline cellulose.

scholarly journals Cellulose Nanocrystals from Fibers of Macauba (Acrocomia Aculeata) and Gravata (Bromelia Balansae) from Brazilian Pantanal

Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1785 ◽  
Author(s):  
Ana Carolina Corrêa ◽  
Vitor Brait Carmona ◽  
José Alexandre Simão ◽  
Fabio Galvani ◽  
José Manoel Marconcini ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Acid Hydrolysis ◽  
Cellulose Nanocrystals ◽  
Cellulose Degradation ◽  
Crystallinity Index ◽  
Palm Tree ◽  
Cellulose Content ◽  
Hydrolysis Time ◽  
Brazilian Pantanal

Cellulose nanocrystals (CNC) were obtained from macauba and gravata fibers. Macauba (or Bocaiuva) is a palm tree found throughout most of Brazil and Gravata is an abundant kind of bromelia with 1–2m long leaves, found in Brazilian Pantanal and Cerrado. The raw fibers of both fibers were mercerized with NaOH solutions and bleached; they were then submitted to acid hydrolysis using H2SO4 at 45 °C, varying the hydrolysis time from 15 up to 75 min. The fibers were analyzed by X-ray diffraction (XRD), FTIR Spectroscopy, scanning electron microscopy (SEM) and thermal stability by thermogravimetric analysis (TG). XRD patterns did not present changes in the crystal structure of cellulose after mercerization, but it was observed a decrease of hemicellulose and lignin contents, and consequently an increase of cellulose content with the increase of NaOH solution concentration in the mercerization. After acid hydrolysis, the cellulose nanocrystals (CNC) were also analyzed by transmission electron microscopy (TEM) which showed an acicular or rod-like aspect and nanometric dimensions of CNC from both fibers, but the higher values of aspect ratio (L/D) were found on CNC obtained from gravata after 45 min of acid hydrolysis. The mercerization and subsequent bleaching of fibers influenced the crystallinity index and thermal stability of the resulting CNC, but their properties are mainly influenced by the hydrolysis time, i. e., there is an increase in crystallinity and thermal stability up to 45 min of hydrolysis, after this time, both properties decrease, probably due to the cellulose degradation by the sulfuric acid.

Enhanced catalytic activity of low-Pt content nanocatalysts supported on hollow carbon spheres for the ORR in alkaline media

MRS Advances ◽  
2020 ◽  
Vol 5 (57-58) ◽  
pp. 2961-2972
Author(s):  
P.C. Meléndez-González ◽  
E. Garza-Duran ◽  
J.C. Martínez-Loyola ◽  
P. Quintana-Owen ◽  
I.L. Alonso-Lemus ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Anion Exchange ◽  
Average Particle Size ◽  
Synthesis Method ◽  
Alkaline Media ◽  
High Catalytic Activity ◽  
Average Particle ◽  
Carbon Spheres ◽  
Hollow Carbon ◽  
Hollow Carbon Spheres

In this work, low-Pt content nanocatalysts (≈ 5 wt. %) supported on Hollow Carbon Spheres (HCS) were synthesized by two routes: i) colloidal conventional polyol, and ii) surfactant-free Bromide Anion Exchange (BAE). The nanocatalysts were labelled as Pt/HCS-P and Pt/HCS-B for polyol and BAE, respectively. The physicochemical characterization of the nanocatalysts showed that by following both methods, a good control of chemical composition was achieved, obtaining in addition well dispersed nanoparticles of less than 3 nm TEM average particle size (d) on the HCS. Pt/HCS-B contained more Pt0 species than Pt/HCS-P, an effect of the synthesis method. In addition, the structure of the HCS remains more ordered after BAE synthesis, compared to polyol. Regarding the catalytic activity for the Oxygen Reduction Reaction (ORR) in 0.5 M KOH, Pt/HCS-P and Pt/HCS-B showed a similar performance in terms of current density (j) at 0.9 V vs. RHE than the benchmark commercial 20 wt. % Pt/C. However, Pt/HCS-P and Pt/HCS-B demonstrated a 6 and 5-fold increase in mass catalytic activity compared to Pt/C, respectively. A positive effect of the high specific surface area of the HCS and its interactions with metal nanoparticles and electrolyte, which promoted the mass transfer, increased the performance of Pt/HCS-P and Pt/HCS-B. The high catalytic activity showed by Pt/HCS-B and Pt/HCS-P for the ORR, even with a low-Pt content, make them promising cathode nanocatalysts for Anion Exchange Membrane Fuel Cells (AEMFC).

A New Method for Direct Determination of the Recoilless Fraction with Application to Magnetic Nanoparticles

2002 ◽  
Vol 721 ◽  
Author(s):  
Monica Sorescu
Keyword(s):  
Room Temperature ◽  
Average Particle Size ◽  
Direct Determination ◽  
Average Particle ◽  
Lattice Method ◽  
Recoilless Fraction ◽  
Single Room ◽  
Magnetite Particles ◽  
Physical Mixtures

AbstractWe propose a two-lattice method for direct determination of the recoilless fraction using a single room-temperature transmission Mössbauer measurement. The method is first demonstrated for the case of iron and metallic glass two-foil system and is next generalized for the case of physical mixtures of two powders. We further apply this method to determine the recoilless fraction of hematite and magnetite particles. Finally, we provide direct measurement of the recoilless fraction in nanohematite and nanomagnetite with an average particle size of 19 nm.

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