scholarly journals Highly Elastic Super-Macroporous Cryogels Fabricated by Thermally Induced Crosslinking of 2-Hydroxyethylcellulose with Citric Acid in Solid State

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6370
Author(s):  
Nadegda Bozova ◽  
Petar D. Petrov
Keyword(s):  
Citric Acid ◽  
Solid State ◽  
Cryogenic Treatment ◽  
Polymeric Materials ◽  
Experimental Conditions ◽  
Thermally Induced ◽  
Photochemical Crosslinking ◽  
Low Toxicity ◽  
Properties Of Materials ◽  
Novel Strategy

Biopolymer materials have been considered a “green” alternative to petroleum-based polymeric materials. Biopolymers cannot completely replace synthetic polymers, but their application should be extended as much as possible, exploiting the benefits of their low toxicity and biodegradability. This contribution describes a novel strategy for the synthesis of super-macroporous 2-hydroxyethylcellulose (HEC) cryogels. The method involves cryogenic treatment of an aqueous solution of HEC and citric acid (CA), freeze drying, and thermally induced crosslinking of HEC macrochains by CA in a solid state. The effect of reaction temperature (70–180 °C) and CA concentration (5–20 mass % to HEC) on the reaction efficacy and physico-mechanical properties of materials was investigated. Highly elastic cryogels were fabricated, with crosslinking carried out at ≥ 100 °C. The storage modulus of the newly obtained HEC cryogels was ca. 20 times higher than the modulus of pure HEC cryogels prepared by photochemical crosslinking. HEC cryogels possess an open porous structure, as confirmed by scanning electron microscopy (SEM), and uptake a relatively large amount of water. The swelling degree varied between 17 and 40, depending on the experimental conditions. The degradability of HEC cryogels was demonstrated by acid hydrolysis experiments.

Solid-state dynamics and single-crystal to single-crystal structural transformations in octakis(3-chloropropyl)octasilsesquioxane and octavinyloctasilsesquioxane

2017 ◽  
Vol 19 (40) ◽  
pp. 27516-27529 ◽  
Author(s):  
A. Kowalewska ◽  
M. Nowacka ◽  
M. Włodarska ◽  
B. Zgardzińska ◽  
R. Zaleski ◽  
...  
Keyword(s):  
Solid State ◽  
Single Crystal ◽  
Structural Transformations ◽  
Crystal Lattices ◽  
Thermally Induced ◽  
Crystal Structural

Thermally induced formation of symmetric crystal lattices in functional POSS proceeds via different mechanisms and results in unique reversible phenomena.

Carbon dots prepared by solid state method via citric acid and 1,10-phenanthroline for selective and sensing detection of Fe2+ and Fe3+

2016 ◽  
Vol 237 ◽  
pp. 408-415 ◽  
Author(s):  
Anam Iqbal ◽  
Yuejun Tian ◽  
Xudong Wang ◽  
Deyan Gong ◽  
Yali Guo ◽  
...  
Keyword(s):  
Citric Acid ◽  
Solid State ◽  
Carbon Dots ◽  
Solid State Method ◽  
State Method

Thermally induced isomerisation and decomposition of diethylenetriamine complexes of nickel(II) in the solid state

1988 ◽  
Vol 13 (4) ◽  
pp. 291-296 ◽  
Author(s):  
Subratanath Koner ◽  
Ashutosh Ghosh ◽  
Nirmalendu Ray Chaudhuri
Keyword(s):  
Solid State ◽  
Thermally Induced

Thermally Induced Self-Assembly and Cyclization of l-Leucyl-l-Leucine in Solid State

2017 ◽  
Vol 121 (36) ◽  
pp. 8603-8610 ◽  
Author(s):  
Marat A. Ziganshin ◽  
Aisylu S. Safiullina ◽  
Alexander V. Gerasimov ◽  
Sufia A. Ziganshina ◽  
Alexander E. Klimovitskii ◽  
...  
Keyword(s):  
Solid State ◽  
Self Assembly ◽  
Thermally Induced

scholarly journals Perovskite Solid-State Electrolytes for Lithium Metal Batteries

Batteries ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 75
Author(s):  
Shuo Yan ◽  
Chae-Ho Yim ◽  
Vladimir Pankov ◽  
Mackenzie Bauer ◽  
Elena Baranova ◽  
...  
Keyword(s):  
Solid State ◽  
Organic Liquid ◽  
Lithium Ion ◽  
Polymeric Materials ◽  
Inorganic Materials ◽  
Lithium Metal ◽  
Structure Property ◽  
Lithium Metal Batteries ◽  
Electrochemical Window ◽  
Solid State Electrolytes

Solid-state lithium metal batteries (LMBs) have become increasingly important in recent years due to their potential to offer higher energy density and enhanced safety compared to conventional liquid electrolyte-based lithium-ion batteries (LIBs). However, they require highly functional solid-state electrolytes (SSEs) and, therefore, many inorganic materials such as oxides of perovskite La2/3−xLi3xTiO3 (LLTO) and garnets La3Li7Zr2O12 (LLZO), sulfides Li10GeP2S12 (LGPS), and phosphates Li1+xAlxTi2−x(PO4)3x (LATP) are under investigation. Among these oxide materials, LLTO exhibits superior safety, wider electrochemical window (8 V vs. Li/Li+), and higher bulk conductivity values reaching in excess of 10−3 S cm−1 at ambient temperature, which is close to organic liquid-state electrolytes presently used in LIBs. However, recent studies focus primarily on composite or hybrid electrolytes that mix LLTO with organic polymeric materials. There are scarce studies of pure (100%) LLTO electrolytes in solid-state LMBs and there is a need to shed more light on this type of electrolyte and its potential for LMBs. Therefore, in our review, we first elaborated on the structure/property relationship between compositions of perovskites and their ionic conductivities. We then summarized current issues and some successful attempts for the fabrication of pure LLTO electrolytes. Their electrochemical and battery performances were also presented. We focused on tape casting as an effective method to prepare pure LLTO thin films that are compatible and can be easily integrated into existing roll-to-roll battery manufacturing processes. This review intends to shed some light on the design and manufacturing of LLTO for all-ceramic electrolytes towards safer and higher power density solid-state LMBs.

scholarly journals Direct assessment of substrate binding to the Neurotransmitter:Sodium Symporter LeuT by solid state NMR

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Simon Erlendsson ◽  
Kamil Gotfryd ◽  
Flemming Hofmann Larsen ◽  
Jonas Sigurd Mortensen ◽  
Michel-Andreas Geiger ◽  
...  
Keyword(s):  
Solid State ◽  
Binding Site ◽  
Solid State Nmr ◽  
Chemical Shifts ◽  
Substrate Binding ◽  
Experimental Conditions ◽  
Specific Chemical ◽  
Sodium Dependent ◽  
Number Of Binding Sites ◽  
Neurotransmitter:Sodium Symporter

The Neurotransmitter:Sodium Symporters (NSSs) represent an important class of proteins mediating sodium-dependent uptake of neurotransmitters from the extracellular space. The substrate binding stoichiometry of the bacterial NSS protein, LeuT, and thus the principal transport mechanism, has been heavily debated. Here we used solid state NMR to specifically characterize the bound leucine ligand and probe the number of binding sites in LeuT. We were able to produce high-quality NMR spectra of substrate bound to microcrystalline LeuT samples and identify one set of sodium-dependent substrate-specific chemical shifts. Furthermore, our data show that the binding site mutants F253A and L400S, which probe the major S1 binding site and the proposed S2 binding site, respectively, retain sodium-dependent substrate binding in the S1 site similar to the wild-type protein. We conclude that under our experimental conditions there is only one detectable leucine molecule bound to LeuT.

scholarly journals Biological solubilization of phosphate rock by solid-state cultivation to produce eco-friendly fertilizers

2021 ◽  
Vol 56 ◽  
Author(s):  
Rodrigo Klaic ◽  
Marcelo Gava Junior ◽  
Camila Florencio ◽  
Caue Ribeiro ◽  
Cristiane Sanchez Farinas
Keyword(s):  
Citric Acid ◽  
Solid State ◽  
Acid Production ◽  
Phosphate Rock ◽  
Saccharum Officinarum ◽  
Citric Acid Production ◽  
Statistical Tool ◽  
P Solubilization ◽  
Low Phosphorus ◽  
Favorable Conditions

Abstract: The objective of this work was to evaluate the solubilization of phosphorus from a phosphate rock by Aspergillus niger, under solid-state cultivation (SSC) in sugarcane (Saccharum officinarum) bagasse, by maximizing the efficiency of citric acid production. The phosphate rock (IPR) chosen for the study is a type of igneous rock with a very low phosphorus solubility, obtained from the Itafós company, in Arraias, in the state of Tocantins, Brazil. The rotatable central composite design (RCCD) was used as a statistical tool to evaluate the effect of the concentrations of the carbon source (sucrose) and of the IPR on the SSC medium as a strategy to improve P solubilization. In the process without the IPR, there was a citric acid production of up to 300 g per kilogram of substrate. The experiments in the RCCD showed that the addition of the IPR affected citric acid production, with values of solubilized P ranging from 1.44 to 2.72 g per kilogram of substrate and of solubilized P yield from 12.96 to 48.94%. The analysis of the solubilized P/sucrose ratio showed favorable conditions for P solubilization and citric acid production. The obtained solubilized P values are promising considering that the IPR has a very low solubilization, with only 8.6% P2O5. Overall, these findings could contribute to the development of biotechnological processes for producing eco-friendly phosphate fertilizers, as an alternative for a more sustainable agriculture.

scholarly journals Water Triggered Shape Memory Materials

2013 ◽  
Vol 3 (1) ◽  
pp. 49-50 ◽  
Author(s):  
Guoguang Niu
Keyword(s):  
Shape Memory ◽  
Shape Recovery ◽  
Shape Memory Polymers ◽  
Electrical Current ◽  
Light Illumination ◽  
Poly Ethylene Glycol ◽  
Thermally Induced ◽  
Permanent Shape ◽  
Poly Ethylene ◽  
Novel Strategy

The term "shape memory effect" refers to the ability of a material to be deformed and fixed into a temporary shape, and to recover its original, permanent shape upon an external stimulus (1). Shape memory polymers have attracted much interest because of their unique properties, and applied tremendously in medical area, such as biodegradable sutures, actuators, catheters and smart stents (2, 3). Shape memory usually is a thermally induced process, although it can be activated by light illumination, electrical current, magnetic, or electromagnetic field (4-6). During the process, the materials are heated directly or indirectly above their glass transition temperature (Tg) or the melting temperature (Tm) in order to recover the original shape. Non-thermally induced shape memory polymers eliminate the temperature constrains and enable the manipulation of the shape recovered under ambient temperature (7, 8). Herein, we report a novel strategy of water induced shape memory, in which the formation and dissolution of poly(ethylene glycol) (PEG) crystal is utilized for the fixation and recovery of temporary deformation of hydrophilic polymer. This water-induced shape recovery is less sensitive to temperature, of which 95% deformation is fixed in circumstance and over 75% recovery is reached even at 0 oC.

By-products from the biodiesel chain as a substrate to citric acid production by solid-state fermentation

2014 ◽  
Vol 32 (7) ◽  
pp. 653-660 ◽  
Author(s):  
Manuella Schneider ◽  
Gabriela F Zimmer ◽  
Ezequiel B Cremonese ◽  
Rosana de C de S Schneider ◽  
Valeriano A Corbellini
Keyword(s):  
Citric Acid ◽  
Solid State ◽  
Solid State Fermentation ◽  
Acid Production ◽  
Citric Acid Production ◽  
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