scholarly journals Effect of Purification Methods on Commercially Available Cellulose Nanocrystal Properties and TEMPO Oxidation

Processes ◽  
2020 ◽  
Vol 8 (6) ◽  
pp. 698
Author(s):  
Manali Banerjee ◽  
Sisira Saraswatula ◽  
Anna Williams ◽  
Blair Brettmann
Keyword(s):  
Acid Hydrolysis ◽  
Surface Properties ◽  
Value Added ◽  
Soxhlet Extraction ◽  
Production Method ◽  
Extraction Methods ◽  
Hydroxyl Groups ◽  
Tempo Oxidation ◽  
Surface Hydroxyl ◽  
Before And After

Cellulose nanocrystals (CNCs) are attractive for use in polymer composites, biomedical applications, and barrier packaging. In all of these applications they are mixed with other components and compatibility is a major design consideration, as CNCs naturally have a high density of surface hydroxyl groups and primarily disperse well in polar media. Numerous surface modification approaches have been used to address these issues, but challenges remain due to the variability in the commercially available CNC materials. CNCs can be produced from biomass using several extraction methods, most notably acid hydrolysis and biomass extraction, also known as the American Value Added Pulping process. The production method of the CNC material has an impact on both physical and surface properties of CNCs, including size, shape, crystal structure, and zeta potential. In addition, post-treatments can be used to purify the CNC material and further alter these properties. This work studies the properties of CNCs from three different commercial suppliers and after conducting three different post-treatments: dialysis, Soxhlet extraction, and acetone washing to understand the effect of the commercial source and purification on CNC surface properties and modification via 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO) mediated oxidation. We show that there is significant variation in CNC physical and surface properties between different commercial suppliers before and after purification. Importantly, we show that for CNCs produced through acid hydrolysis, acetone washing or Soxhlet extraction in ethanol decreases the achievable degree of TEMPO modification, but makes it more consistent between the different commercial suppliers. This has important implications for improving reproducibility in CNC research as well as aiding the expanding fields of applications.

scholarly journals Analysis of Carbon Tetrachloride-Extractable Species from Daxing Bituminous Coal

2020 ◽  
Vol 10 (2) ◽  
pp. 494
Author(s):  
Caixia Jv ◽  
Fenggang Li ◽  
Peng Yan ◽  
Mengmeng Fan ◽  
Linlin Jia ◽  
...  
Keyword(s):  
Carbon Tetrachloride ◽  
Soxhlet Extraction ◽  
Extraction Methods ◽  
The Other ◽  
Radical Mechanism ◽  
Free Radical Mechanism ◽  
Assisted Extraction ◽  
Before And After ◽  
Ultrasonic Assisted ◽  
Extraction Processes

Soxhlet extraction (SE), ultrasonic-assisted extraction (UAE), and microwave-assisted extraction (MAE) were carried out on Daxing coal with carbon tetrachloride. The extracted components were analyzed by GC-MS while the residues of the coal after extractions were analyzed by FT-IR spectroscopy. The obtained IR spectra indicated that the functional groups were barely changed in strength for the coal before and after extractions concluding that the macromolecular structures of coal were not destroyed in the extraction processes. XRD diagrams showed the peak around θ = 47 was totally disappeared by all the three extractions, indicating that the graphite-like structural substances in the coal were totally destroyed in the extraction processes. GC/MS analysis showed that: (1) The SE method extracted the least number of substances from the coal; on the other hand, the extracted compounds are largely chlorinated which can be explained by the free radical mechanism. (2) MAE extracted 75 organic compounds of which 53 are oxygen-containing substances. A small portion of non-alkanes (1.19%) was found, which is in contrast to the other two extraction methods. Moreover, a few biomarker compounds were also identified including hexaoxane, 2-methylcholest-3-ene, 6,9,12-tripropylheptadecane, and 17α-21β-28,30-bisnorhopane. (3) The three extraction methods gave totally different extraction patterns for the same coal, highlighting that the extraction method can dominate the outcome of the extracted products. The mechanisms behind these extraction processes are discussed. This study provides a base for the future choice of the extraction methods in terms of outcomes of the extraction products.

scholarly journals Tailoring the component of protein corona via simple chemistry

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Xiang Lu ◽  
Peipei Xu ◽  
Hong-Ming Ding ◽  
You-Sheng Yu ◽  
Da Huo ◽  
...  
Keyword(s):  
Surface Properties ◽  
Blood Circulation ◽  
Molecular Simulations ◽  
Protein Corona ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Surface Hydroxyl ◽  
Surface Hydroxyl Groups ◽  
In Vitro Measurements

Abstract Control over the protein corona of nanomaterials allows them to function better. Here, by taking graphene/gold as examples, we comprehensively assessed the association of surface properties with the protein corona. As revealed by in vitro measurements and computations, the interaction between graphene/gold and HSA/IgE was inversely correlated with the hydroxyl group availability, whereas the interaction between that and ApoE was comparatively less relevant. Molecular simulations revealed that the number and the distribution of surface hydroxyl groups could regulate the manner in which nanomaterials interact with proteins. Moreover, we validated that ApoE pre-adsorption before injection enhances the blood circulation of nanomaterials relative to their pristine and IgE-coated counterparts. This benefit can be attributed to the invulnerability of the complementary system provided by ApoE, whose encasement does not increase cytotoxicity. Overall, this study offers a robust yet simple way to create protein corona enriched in dysopsonins to realize better delivery efficacy.

Study on Determination of Grease Content Inner Leather by Ultrasonic-Combining-Soxhlet Extraction Method

2011 ◽  
Vol 393-395 ◽  
pp. 1456-1461
Author(s):  
Xiao Min Luo ◽  
Peng Ni Li ◽  
Guo Hui Zhao ◽  
Dong Qiu Wu
Keyword(s):  
Conventional Method ◽  
Extraction Method ◽  
Soxhlet Extraction ◽  
Extraction Methods ◽  
Dichloromethane Solution ◽  
Ultrasonic Technology ◽  
Before And After ◽  
Ultrasound Technology ◽  
Conventional Extraction

Different shaped samples of soaked leather in dichloromethane solution was pretreated by ultrasound technology, then the grease content in solution was measured by soxhlet extraction method. Samples before and after extraction were respectively made into histology slices in order to visually observe the situation of grease content. Results showed that compared with conventional extraction methods, extraction time was reduced to1/6~1/7 times and 50% solvent was saved by ultrasonic technology. Histology photos exhibited a cleaner extraction situation, which indicated that ultrasound technology behaved more efficient than conventional method in grease extraction.

Bleaching ability of pre-hydrolyzed pulps in the context of a biorefinery mill

TAPPI Journal ◽  
2013 ◽  
Vol 12 (11) ◽  
pp. 49-53 ◽  
Author(s):  
CHRISTINE CHIRAT ◽  
LUCIE BOIRON ◽  
DOMINIQUE LACHENAL
Keyword(s):  
Carbon Content ◽  
Acid Hydrolysis ◽  
13C Nmr ◽  
Kraft Lignin ◽  
Kappa Number ◽  
Hydroxyl Groups ◽  
Kraft Pulps ◽  
Quaternary Carbon ◽  
Oxygen Delignification

Autohydrolysis and acid hydrolysis treatments were applied on mixed softwood chips. The cooking ability was studied by varying the alkali and duration of the cook. Pulps with kappa numbers varying from 30 to 70 were obtained. The bleaching ability of these pulps was studied and compared to control kraft pulps. The prehydrolyzed pulps were shown to be more efficiently delignified by oxygen than the control kraft pulps starting from the same kappa number. Furthermore, the final bleaching was also easier for these pulps. It was also shown that extensive oxygen delignification applied on high-kappa pre-hydrolyzed pulps could be a way to improve the overall yield, which is a prerequisite for the development of such biorefinery concepts. Lignin was isolated from the control kraft and the two pre-hydrolyzed kraft pulps and analyzed by 13C NMR. Lignins from pre-hydrolyzed kraft pulps had similar free phenolic groups content to the control kraft lignin, but their aliphatic hydroxyl groups and β-O-4 content were lower than for the control lignin. The quaternary carbon content was the same for all the samples.

Extraction and Quantification of Eugenol from Clove Buds Using HPLC

2020 ◽  
Vol 7 (1) ◽  
pp. 17-23
Author(s):  
Khadiza Fitri Shafira ◽  
Abul Kalam Azad ◽  
Zubair Khalid Labu ◽  
Abul Bashar Mohammed Helal Uddin
Keyword(s):  
Processing Time ◽  
Soxhlet Extraction ◽  
Extraction Methods ◽  
Past Study ◽  
Solvent Ratio ◽  
Clove Oil ◽  
Microwave Assisted ◽  
Assisted Extraction ◽  
Significant Difference ◽  
Clove Essential Oil

Background: Eugenol is the main constituent of clove essential oil. Past studies have found that clove oil has diverse uses in the pharmaceutical field due to its antioxidant, antibacterial and anesthetic properties. Objective: This work compares the performance of different extraction methods and factors and identifies the effect of the treatments on oil yields and eugenol content. Materials and Methods: Maceration, Hydro distillation, microwave-assisted extraction (MAE), and Soxhlet were performed. The best technique was identified according to yield and content. Further studies were conducted to examine the effects of different factors, such as solvent types (ethanol and methanol) and sample-to-solvent ratio (1:10 and 1:15). HPLC UV-Vis was utilized in the analysis of eugenol concentration. Results and Discussion: Soxhlet extraction provided the highest yield (39.98%) and eugenol content (15.83%), compared to other methods. The results observed from several Soxhlet extraction factors showed that there is no significant difference between the different factors. In the meantime, methanol 1:15 provided the greatest amount of yields (57.83%) and eugenol content (22.21%). In this regard, the higher ratio resulted in higher eugenol content. Conclusion: The results obtained are less comparable because the processing time, the working solvent, and the separation technique were carried out differently for each method. In the meantime, as there is no past study that compared the selected methods and factors, this study’s findings will contribute substantially to fill the gap in this field.

Comparison of extraction efficiency of various methods to extract L-DOPA from Mucuna pruriens (L.) DC.

2017 ◽  
Vol 6 (04) ◽  
pp. 5343
Author(s):  
Ragni Vora ◽  
Ambika N. Joshi* ◽  
Nitesh C. Joshi
Keyword(s):  
Extraction Efficiency ◽  
Soxhlet Extraction ◽  
Extraction Methods ◽  
Mucuna Pruriens ◽  
Water Mixture ◽  
Uv Detector ◽  
Pharmacological Activities ◽  
Hplc Mobile Phase ◽  
Plant Sources ◽  
Seed Extracts

Mucuna pruriens seeds are noted to be a natural source of L-DOPA and are also used as a substitute for the synthetic L-DOPA. In the present study; attempts are made to develop suitable method(s) for extraction of L-DOPA from the powdered seeds of Mucuna pruriens using different solvents and conditions. The Seed powder was subjected to 7 different extraction methods and Method 1 was subjected to various solvent concentrations. Some methods used de-fatting procedure, either the method was cold maceration or in high temperature. Soxhlet extraction was also used in one of the extraction methods. All the extracts were analyzed using RP-HPLC. Mobile Phase used was Water: Methanol: AcetoNitrile (100:60:40) (v/v) containing 0.2% Triethylamine, pH = 3.3 and monitored at 280 nm with variable wavelength UV detector. The extraction was best with Methanol Water mixture in a cold maceration technique and overall gives good extraction efficiency of 13.36 % L-DOPA and id the best method giving highest extraction efficiency. The De-fatting method was the 2nd best methods giving approximately 8.8% L-DOPA and Method 5 viz, heat reflux method gives 8.7% L-DOPA making it the 3rd best method. There are not many studies done for optimization of extraction technique for L-DOPA despite an extensive work is reported for isolation, identification and pharmacological activities of L-DOPA from various plant sources. Keeping this in view, present investigation was done to study the extraction efficiency of various extraction methods of L-DOPA content in seed extracts of Mucuna pruriens and compare it.

The synthesis and structure of silica-supported bis(h5-cyclopentadienyl)dichlorotitanium(IV) complexes

1986 ◽  
Vol 51 (7) ◽  
pp. 1430-1438 ◽  
Author(s):  
Alena Reissová ◽  
Zdeněk Bastl ◽  
Martin Čapka
Keyword(s):  
Free Surface ◽  
Hydroxyl Groups ◽  
Titanium Complex ◽  
Surface Hydroxyl ◽  
Surface Hydroxyl Groups ◽  
Free Hydroxyl ◽  
Cyclopentadienyl Anion

The title complexes have been obtained by functionalization of silica with cyclopentadienylsilanes of the type Rx(CH3)3 - xSi(CH2)nC5H5 (x = 1-3, n = 0, 1, 3), trimethylsilylation of free surface hydroxyl groups, transformation of the bonded cyclopentadienyl group to the cyclopentadienyl anion, followed by coordination of (h5-cyclopentadienyl)trichlorotitanium. The effects of single steps of the above immobilization on texture of the support, the number of free hydroxyl groups, the coverage of the surface by cyclopentadienyl groups and the degree of their utilization in anchoring the titanium complex have been investigated. ESCA study has shown that the above anchoring leads to formation of the silica-supported bis(h5-cyclopentadienyl)dichlorotitanium(IV) complex.

scholarly journals Chitosan Adsorbent Derivatives for Pharmaceuticals Removal from Effluents: A Review

Macromol ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 130-154
Author(s):  
Efstathios V. Liakos ◽  
Maria Lazaridou ◽  
Georgia Michailidou ◽  
Ioanna Koumentakou ◽  
Dimitra A. Lambropoulou ◽  
...  
Keyword(s):  
Emerging Contaminants ◽  
Low Cost ◽  
Value Added ◽  
Ph Effects ◽  
Hydroxyl Groups ◽  
Research Papers ◽  
Natural Polysaccharide ◽  
Best Fitting ◽  
Isotherm And Kinetic Models ◽  
Published Research

Chitin is mentioned as the second most abundant and important natural biopolymer in worldwide scale. The main sources for the extraction and exploitation of this natural polysaccharide polymer are crabs and shrimps. Chitosan (poly-β-(1 → 4)-2-amino-2-deoxy-d-glucose) is the most important derivative of chitin and can be used in a wide variety of applications including cosmetics, pharmaceutical and biomedical applications, food, etc., giving this substance high value-added applications. Moreover, chitosan has applications in adsorption because it contains amino and hydroxyl groups in its molecules, and can thus contribute to many possible adsorption interactions between chitosan and pollutants (pharmaceuticals/drugs, metals, phenols, pesticides, etc.). However, it must be noted that one of the most important techniques of decontamination is considered to be adsorption because it is simple, low-cost, and fast. This review emphasizes on recently published research papers (2013–2021) and briefly describes the chemical modifications of chitosan (grafting, cross-linking, etc.), for the adsorption of a variety of emerging contaminants from aqueous solutions, and characterization results. Finally, tables are depicted from selected chitosan synthetic routes and the pH effects are discussed, along with the best-fitting isotherm and kinetic models.

Sign in / Sign up

Export Citation Format

Share Document