scholarly journals Utilization of Cellulose to Its Full Potential: A Review on Cellulose Dissolution, Regeneration, and Applications

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4344
Author(s):  
Sanjit Acharya ◽  
Sumedha Liyanage ◽  
Prakash Parajuli ◽  
Shaida Sultana Rumi ◽  
Julia L. Shamshina ◽  
...  

As the most abundant natural polymer, cellulose is a prime candidate for the preparation of both sustainable and economically viable polymeric products hitherto predominantly produced from oil-based synthetic polymers. However, the utilization of cellulose to its full potential is constrained by its recalcitrance to chemical processing. Both fundamental and applied aspects of cellulose dissolution remain active areas of research and include mechanistic studies on solvent–cellulose interactions, the development of novel solvents and/or solvent systems, the optimization of dissolution conditions, and the preparation of various cellulose-based materials. In this review, we build on existing knowledge on cellulose dissolution, including the structural characteristics of the polymer that are important for dissolution (molecular weight, crystallinity, and effect of hydrophobic interactions), and evaluate widely used non-derivatizing solvents (sodium hydroxide (NaOH)-based systems, N,N-dimethylacetamide (DMAc)/lithium chloride (LiCl), N-methylmorpholine-N-oxide (NMMO), and ionic liquids). We also cover the subsequent regeneration of cellulose solutions from these solvents into various architectures (fibers, films, membranes, beads, aerogels, and hydrogels) and review uses of these materials in specific applications, such as biomedical, sorption, and energy uses.

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Vikrant Abbot ◽  
Poonam Sharma

AbstractFlavonoids amongst the class of secondary metabolites possess numerous health benefits, are known for its use in pharmaceutical industry. Quercetin, a flavonoid has more prominent medical advantages however its utilization is constrained because of various instability and insolubility issues and therefore, taken into consideration for studying its physico-chemical properties. In view of that, the thermodynamic and thermoacoustic properties of quercetin were examined in presence of cationic surfactant cetyltrimethylammonium bromide (CTAB) at different hydroethanolic concentrations and temperatures. The conductivity studies were used to calculate change in enthalpy (∆Hom), change in entropy (∆Som) and change in Gibbs free Energy (∆Gom) of micellization. The interactions between quercetin and CTAB were found to be endothermic, entropically controlled and spontaneous. Further, ultrasonic sound velocity and density studies were carried out and utilized for the calculation of thermoacoustic parameters i.e. apparent molar volume and apparent molar compressibility. Thermoacoustic properties revealed that at higher surfactant concentration, hydrophobic interactions are dominant. The results suggested that the flavonoid-surfactant interactions in hydroethanolic solutions is more favourable as compared with aqueous solution. Overall, the data is favourable for the framework to be used for detailing advancement, drug development, drug industry, pharmaceutical industry, medical administration and formulation development studies.


2018 ◽  
Vol 44 ◽  
pp. 00014
Author(s):  
Maciej Borowczak ◽  
Stanisław Frąckowiak

Electrospinning of biodegradable poly (butylene succinate) has been performed from different solvent systems. Alternation of process parameters resulted in respective changes of the surface structure topography which was evaluated by using scanning electron microscopy (SEM).


BioResources ◽  
2015 ◽  
Vol 10 (3) ◽  
pp. 3811-3814 ◽  
Author(s):  
Björn Lindman ◽  
Bruno Medronho

Cellulose dissolution and regeneration are old topics that have recently gained renewed attention. This is reflected in both applications – earlier and novel – and in scientific controversies. There is a current discussion in the literature on the balance between hydrogen bonding and hydrophobic interactions in controlling the solution behavior of cellulose. Some of the key ideas are recalled.


Molecules ◽  
2020 ◽  
Vol 25 (24) ◽  
pp. 5901
Author(s):  
Eugene V. Radchenko ◽  
Alina S. Dyabina ◽  
Vladimir A. Palyulin

Permeation through the blood–brain barrier (BBB) is among the most important processes controlling the pharmacokinetic properties of drugs and other bioactive compounds. Using the fragmental (substructural) descriptors representing the occurrence number of various substructures, as well as the artificial neural network approach and the double cross-validation procedure, we have developed a predictive in silico LogBB model based on an extensive and verified dataset (529 compounds), which is applicable to diverse drugs and drug-like compounds. The model has good predictivity parameters (Q2=0.815, RMSEcv=0.318) that are similar to or better than those of the most reliable models available in the literature. Larger datasets, and perhaps more sophisticated network architectures, are required to realize the full potential of deep neural networks. The analysis of fragment contributions reveals patterns of influence consistent with the known concepts of structural characteristics that affect the BBB permeability of organic compounds. The external validation of the model confirms good agreement between the predicted and experimental LogBB values for most of the compounds. The model enables the evaluation and optimization of the BBB permeability of potential neuroactive agents and other drug compounds.


2011 ◽  
Vol 8 (4) ◽  
pp. 1638-1643 ◽  
Author(s):  
R. Jameel Mhessn ◽  
L. Abd-Alredha ◽  
R. Al-Rubaie ◽  
A. Fuad Khudair Aziz

Polymeric blends as potential wound dressing were prepared. Natural polymer (Tannin) and synthetic polymers (PVA and PEG) were used to prepare heterogeneous blends. The product was identified by spectrophotometry. A diaphragm cell was used to measure the diffusion coefficient (D). The result shown the PEG-PVA disk was very faster permeability for all solution. The D of PVA/ PEG-Tannin blend was 0.184x10-3cm2/s higher than Tannin-PEG blend was 0.038x10-3cm2/s. The natural phenolic compounds that can be used artificial membrane to inhibit growth or kill microorganism such as bacteria or fungi.


2019 ◽  
Vol 16 (3) ◽  
pp. 353-363 ◽  
Author(s):  
Che Puteh Osman ◽  
Nor Hadiani Ismail ◽  
Aty Widyawaruyanti ◽  
Syahrul Imran ◽  
Lidya Tumewu ◽  
...  

Background: A phytochemical study on medicinal plants used for the treatment of fever and malaria in Africa yielded metabolites with potential antiplasmodial activity, many of which are Anthraquinones (AQ). AQs have similar sub-structure as naphthoquinones and xanthones, which were previously reported as novel antiplasmodial agents. </P><P> Objective: The present study aimed to investigate the structural requirements of 9,10- anthraquinones with hydroxy, methoxy and methyl substituents to exert strong antiplasmodial activity and to investigate their possible mode of action. </P><P> Methods: Thirty-one AQs were synthesized through Friedel-Crafts reaction and assayed for antiplasmodial activity in vitro against Plasmodium falciparum (3D7). The selected compounds were tested for toxicity and probed for their mode of action against β-hematin dimerization through HRP2 and lipid catalyses. The most active compounds were subjected to a docking study using AutoDock 4.2. </P><P> Results: The active AQs have similar common structural characteristics. However, it is difficult to establish a structure-activity relationship as certain compounds are active despite the absence of the structural features exhibited by other active AQs. They have either ortho- or meta-arranged substituents and one free hydroxyl and/or carbonyl groups. When C-6 is substituted with a methyl group, the activity of AQs generally increased. 1,3-DihydroxyAQ (15) showed good antiplasmodial activity with an IC50 value of 1.08 &#181;M, and when C-6 was substituted with a methyl group, 1,3- dihydroxy-6-methylAQ (24) showed stronger antiplasmodial activity with an IC50 value of 0.02 &#181;M, with better selectivity index. Compounds 15 and 24 showed strong HRP2 activity and mild toxicity against hepatocyte cells. Molecular docking studies showed that the hydroxyl groups at the ortho (23) and meta (24) positions are able to form hydrogen bonds with heme, of 3.49 Å and 3.02 Å, respectively. </P><P> Conclusion: The activity of 1,3-dihydroxy-6-methylAQ (24) could be due to their inhibition against the free heme dimerization by inhibiting the HRP2 protein. It was further observed that the anthraquinone moiety of compound 24 bind in parallel to the heme ring through hydrophobic interactions, thus preventing crystallization of heme into hemozoin.


Author(s):  
Luis Alves ◽  
Bruno F. Medronho ◽  
Filipe E. Antunes ◽  
Anabela Romano ◽  
Maria G. Miguel ◽  
...  

RSC Advances ◽  
2017 ◽  
Vol 7 (28) ◽  
pp. 17451-17461 ◽  
Author(s):  
Ashley J. Holding ◽  
Arno Parviainen ◽  
Ilkka Kilpeläinen ◽  
Ana Soto ◽  
Alistair W. T. King ◽  
...  

Hydrophobic, long-chain tetraalkylphosphonium acetate salts (ionic liquids) were combined with DMSO and the feasibility of these solvent systems for cellulose dissolution and regeneration was studied.


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