Characterization of a lignin-based gel responsive to aqueous binary solvents and pH

Holzforschung ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Shogo Taira ◽  
Yuriko Usukura ◽  
Mitsukuni Nishida ◽  
Kengo Shigetomi ◽  
Yasumitsu Uraki
Keyword(s):  
Pure Water ◽  
Functional Materials ◽  
Diglycidyl Ether ◽  
Binary Solvents ◽  
Ph Response ◽  
H Nmr ◽  
Swelling Mechanism ◽  
Poly Ethylene ◽  
Acetic Acid Lignin ◽  
Main Component

Abstract A lignin-based gel (AL-PE gel) was obtained from hardwood acetic acid lignin (AL) and poly(ethylene glycol) diglycidyl ether (PE) as a cross-linker at a high AL concentration, while the reaction at a lower AL concentration yielded an amphipathic derivative (am-AL-PE). The gel has been reported to swell in aqueous ethanol but shrink in pure water and ethanol. In the present work, swelling behaviors in other aqueous binary solvents and the swelling mechanism were investigated to explore novel lignin-based functional materials, such as stimuli-and/or environment-responsive gels. The AL-PE gel swelled in aqueous methanol, isopropanol, acetone, and tetrahydrofuran, and the order of swelling in the solvents was consistent with that of the am-AL-PE. Spin-spin relaxation time (T 2 ) measurements with 1H NMR analysis of the gel in aqueous acetone revealed that gel swelling was closely related to an increasing T 2 of acetone bound to the gel network. The nature of the lignin moiety in the gel also enabled a pH response, and the amphipathic nature of the gel provided it with a function as an absorbent for cationic surfactants. The results of this study can contribute to the valorization of lignin as a main component for solvent sensors and environmental purification materials.

scholarly journals Synthesis of Network Polymers by Means of Addition Reactions of Multifunctional-Amine and Poly(ethylene glycol) Diglycidyl Ether or Diacrylate Compounds

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2047
Author(s):  
Naofumi Naga ◽  
Mitsusuke Sato ◽  
Kensuke Mori ◽  
Hassan Nageh ◽  
Tamaki Nakano
Keyword(s):  
Ethylene Glycol ◽  
Room Temperature ◽  
Addition Reaction ◽  
Monomer Concentration ◽  
Diglycidyl Ether ◽  
Porous Polymers ◽  
Addition Reactions ◽  
Poly Ethylene Glycol ◽  
Network Polymers ◽  
Poly Ethylene

Addition reactions of multi-functional amine, polyethylene imine (PEI) or diethylenetriamine (DETA), and poly(ethylene glycol) diglycidyl ether (PEGDE) or poly(ethylene glycol) diacrylate (PEGDA), have been investigated to obtain network polymers in H2O, dimethyl sulfoxide (DMSO), and ethanol (EtOH). Ring opening addition reaction of the multi-functional amine and PEGDE in H2O at room temperature or in DMSO at 90 °C using triphenylphosphine as a catalyst yielded gels. Aza-Michael addition reaction of the multi-functional amine and PEGDA in DMSO or EtOH at room temperature also yielded corresponding gels. Compression test of the gels obtained with PEI showed higher Young’s modulus than those with DETA. The reactions of the multi-functional amine and low molecular weight PEGDA in EtOH under the specific conditions yielded porous polymers induced by phase separation during the network formation. The morphology of the porous polymers could be controlled by the reaction conditions, especially monomer concentration and feed ratio of the multi-functional amine to PEGDA of the reaction system. The porous structure was formed by connected spheres or a co-continuous monolithic structure. The porous polymers were unbreakable by compression, and their Young’s modulus increased with the increase in the monomer concentration of the reaction systems. The porous polymers absorbed various solvents derived from high affinity between the polyethylene glycol units in the network structure and the solvents.

Sulphonated Poly(ethylene terephthalate)/Poly(3-hydroxy butyrate) Blends: Miscibility, Thermal Behavior, and Specific Interactions

e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Rafael Silva ◽  
Gizilene M. Carvalho ◽  
Edvani C. Muniz ◽  
Gentil J. Vidotti ◽  
Adley F. Rubira
Keyword(s):  
Carbonyl Group ◽  
Specific Interaction ◽  
Thermal Stabilities ◽  
Immiscible Blends ◽  
H Nmr ◽  
Miscible Blends ◽  
Poly Ethylene Terephthalate ◽  
Concentration Changes ◽  
Poly Ethylene ◽  
C Nmr

AbstractPETs/PHB blends with different compositions were produced by “casting” method. The blends were investigated by TGA, DSC, 1H and 13C NMR and FTIR. Phase separation occurred during blend preparation. PETs and PHB were present in both formed phases. The phases presented different thermal stabilities unrelated to phase component concentration changes. The miscibility study by DSC showed that PHB-phase rich blends are immiscible, whereas the PETs-rich phase blends are miscible. The 1H NMR spectra of the miscible blends exhibited a peak close to the PHB methylene signal, which is in accordance with the interaction between the PETs SO3 - groups and the PHB carbonyl groups. This interaction result in a shift of the PHB carbonyl group absorption band in the FTIR spectra and a variation in the chemical shift of the PHB carbonyl group resonance peak in solid state 13C NMR. No specific interaction was observed for the immiscible blends.

scholarly journals Fabrication and Properties of High-Content Keratin/Poly (Ethylene Oxide) Blend Nanofibers Using Two-Step Cross-Linking Process

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Yong Liu ◽  
Xia Yu ◽  
Jia Li ◽  
Jie Fan ◽  
Meng Wang ◽  
...  
Keyword(s):  
Ethylene Oxide ◽  
Average Diameter ◽  
Diglycidyl Ether ◽  
Cross Linking ◽  
Electrospun Fibers ◽  
Hydrophobic Property ◽  
Poly Ethylene Oxide ◽  
Cross Linker ◽  
Poly Ethylene ◽  
Nanofiber Mats

High-content keratin/poly (ethylene oxide) (PEO) (90/10) blend nanofibers were prepared by electrospinning combined with a two-step cross-linking process. The keratin/PEO aqueous solution was firstly mixed with ethylene glycol diglycidyl ether (EGDE) as cross-linker and then electrospun into nanofibers. The resulting nanofibrous mats were cross-linked with EGDE vapor to decrease the solubility of nanofibers in water. The morphologies and properties of electrospun fibers were investigated by SEM, FTIR, TG, XRD, and contact angle testing, respectively. The results showed that the morphologies of nanofibers were uniform at the fiber average diameter of 300 nm with negligible bead defects by adding EGDE to keratin/PEO solutions. The cross-linking results showed that EGDE vapor could improve the hydrophobic property of blended nanofibers. The crystallinity of the keratin/PEO blend nanofiber mat increased from 13.14% for the uncross-linked sample to 21.54% and 35.15% for the first cross-linked and second cross-linked samples, respectively. Free defect nanofiber mats with high keratin content producing from this two-step cross-linking process are particularly promising for tissue engineering and cell-seeded scaffold.

Temperature Dependent Solubility of Benzoic Acid in Aqueous Phase and Aqueous Mixtures of Aliphatic Alcohols

2020 ◽  
Vol 234 (11-12) ◽  
pp. 1771-1787
Author(s):  
Sayyar Muhammad ◽  
Sofia Sanam ◽  
Hamayun Khan ◽  
Akhtar Muhammad ◽  
Sabiha Sultana
Keyword(s):  
Benzoic Acid ◽  
Aqueous Phase ◽  
Linear Trend ◽  
Pure Water ◽  
Binary Solvents ◽  
Aqueous Mixtures ◽  
Analytical Technique ◽  
Temperature Range ◽  
Acid Solubility ◽  
Ethanol In Water

AbstractThe benzoic acid solubility in aqueous phase and in various aqueous mixtures of methanol, ethanol and 2-propanol was determined at temperatures ranging from 303 to 333 K by an analytical technique. The results showed that the solubility of the acid in alcohols-water binary mixtures is high as compared to pure aqueous phase. The addition of alcohols to water favors the dissolution of benzoic acid which increases further with the increase in alcohols content of water within the investigated temperature range. The benzoic acid solubility in water alone and aqueous mixtures of the selected alcohols was in the order of; 2-propanol in water > ethanol in water > methanol in water > pure water. It is also observed that within the investigated temperature range, the acid solubility increases with rise in temperature in both the aqueous phase and alcohols-water binary solvents. The logarithm of the mole fraction of the acid’s solubility also showed a linear trend against the temperature. The experimental results obtained in the current study were compared with the reported literature for the studied acid and other organic acids in various solvents and showing a good agreement. The study will have implications in the processes involving separation, crystallization and pharmaceutical formulation in various industries.

scholarly journals Hydrophobization of Tobacco Mosaic Virus to Control the Mineralization of Organic Templates

Nanomaterials ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 800 ◽  
Author(s):  
Petia Atanasova ◽  
Vladimir Atanasov ◽  
Lisa Wittum ◽  
Alexander Southan ◽  
Eunjin Choi ◽  
...  
Keyword(s):  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Functional Materials ◽  
Covalent Attachment ◽  
Virus Surface ◽  
Polymer Molecules ◽  
Synthetic Strategy ◽  
Chemical Coupling ◽  
Poly Ethylene ◽  
Poly Propylene

The robust, anisotropic tobacco mosaic virus (TMV) provides a monodisperse particle size and defined surface chemistry. Owing to these properties, it became an excellent bio-template for the synthesis of diverse nanostructured organic/inorganic functional materials. For selective mineralization of the bio-template, specific functional groups were introduced by means of different genetically encoded amino acids or peptide sequences into the polar virus surface. An alternative approach for TMV surface functionalization is chemical coupling of organic molecules. To achieve mineralization control in this work, we developed a synthetic strategy to manipulate the surface hydrophilicity of the virus through covalent coupling of polymer molecules. Three different types of polymers, namely the perfluorinated (poly(pentafluorostyrene) (PFS)), the thermo-responsive poly(propylene glycol) acrylate (PPGA), and the block-copolymer polyethylene-block-poly(ethylene glycol) were examined. We have demonstrated that covalent attachment of hydrophobic polymer molecules with proper features retains the integrity of the virus structure. In addition, it was found that the degree of the virus hydrophobicity, examined via a ZnS mineralization test, could be tuned by the polymer properties.

scholarly journals Field evaporation and atom probe tomography of pure water tips

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
T. M. Schwarz ◽  
E. M. Weikum ◽  
K. Meng ◽  
E. Hadjixenophontos ◽  
C. A. Dietrich ◽  
...  
Keyword(s):  
Protein Interactions ◽  
Atom Probe Tomography ◽  
Pure Water ◽  
Biological Systems ◽  
Laser Pulses ◽  
Atom Probe ◽  
Virus Protein ◽  
Field Evaporation ◽  
Behavior Understanding ◽  
Main Component

AbstractMeasuring biological samples by atom probe tomography (APT) in their natural environment, i.e. aqueous solution, would take this analytical method, which is currently well established for metals, semi-conductive materials and non-metals, to a new level. It would give information about the 3D chemical structure of biological systems, which could enable unprecedented insights into biological systems and processes, such as virus protein interactions. For this future aim, we present as a first essential step the APT analysis of pure water (Milli-Q) which is the main component of biological systems. After Cryo-preparation, nanometric water tips are field evaporated with assistance by short laser pulses. The obtained data sets of several tens of millions of atoms reveal a complex evaporation behavior. Understanding the field evaporation process of water is fundamental for the measurement of more complex biological systems. For the identification of the individual signals in the mass spectrum, DFT calculations were performed to prove the stability of the detected molecules.

scholarly journals Qualitative and quantitative evaluation of melittin in honeybee venom and drug products containing honeybee venom

2013 ◽  
Vol 57 (2) ◽  
pp. 37-44 ◽  
Author(s):  
Ghasem Haghi ◽  
Alireza Hatami ◽  
Mehdi Mehran
Keyword(s):  
High Performance ◽  
Pure Water ◽  
Gradient Elution ◽  
High Performance Liquid Chromatographic ◽  
Hplc Method ◽  
Honeybee Venom ◽  
Drug Products ◽  
Rp Hplc ◽  
Validation Parameters ◽  
Main Component

Abstract A reverse-phase high-performance liquid chromatographic (RP -HPLC ) method was developed and validated for the analysis of honeybee venom samples and drug products containing honeybee venom. The validation parameters were linearity, sensitivity, precision, and recovery. Melittin is the main component of honeybee venom was extracted with pure water, and then evaluated by RP -HPLC with a photodiode array (PDA ) detector. Separation of the samples was achieved on a Europa Protein C18 column with linear gradient elution of acetonitrile and 0.4% phosphoric acid at 25°C. There was a flow rate of 1 mL/min. Detection was set at 220 nm. Limits of detection (LOD ) and quantification (LO Q) for melittin were 1.1 and 3.2 μg/mL, respectively. The amount of melittin in honeybee venom samples ranged from 21.9 to 66.4 %.

Improving the properties of recycled PET/PEN blends by using different chain extenders

2016 ◽  
Vol 36 (6) ◽  
pp. 615-624 ◽  
Author(s):  
Simge Can ◽  
N. Gamze Karsli ◽  
Sertan Yesil ◽  
Ayse Aytac
Keyword(s):  
Ethylene Terephthalate ◽  
Chain Extender ◽  
Degree Of Crystallinity ◽  
Recycled Pet ◽  
H Nmr ◽  
Loading Level ◽  
Poly Ethylene Terephthalate ◽  
Chain Extenders ◽  
Izod Impact ◽  
Poly Ethylene

Abstract The main aim of this study was to improve the mechanical properties of the recycled poly(ethylene terephthalate)/poly(ethylene 2,6-naphthalate) (r-PET/PEN) blends by enhancing the miscibility between PET and PEN with the usage of chain extenders. This idea was novel for the recycled PET-based r-PET/PEN blends, as investigation of the effects of the chain extender usage on the properties of r-PET/PEN blends has not been studied in the literature, according to our knowledge. 1,4-Phenylene-bis-oxazoline (PBO), 1,4-phenylene-di-isocyanate (PDI), and triphenyl phosphite (TPP) were selected as chain extenders. The maximum tensile strength value was observed for the 1.0PDI sample. Moreover, PDI-based blends exhibited better Izod impact strength when compared with all other samples. The miscibility and degree of crystallinity values of all blends were discussed by means of thermal analysis. 1H-nuclear magnetic resonance (1H-NMR) analysis was carried out to determine transesterification reaction levels. According to 1H-NMR results, the increase in the level of transesterification was around 40% with the usage of PDI. The optimum loading level for selected chain extenders was determined as 1 wt.%, and PDI-based blends exhibited better properties when compared with those of the blends based on PBO and TPP at this loading level.

Preparation and physical characterization of strongly swellable oligo(oxyethylene) lignin hydrogels

Holzforschung ◽  
2011 ◽  
Vol 65 (3) ◽  
Author(s):  
Lars Passauer ◽  
Klaus Fischer ◽  
Falk Liebner
Keyword(s):  
Dynamic Viscosity ◽  
Loss Modulus ◽  
Gelation Time ◽  
Rheological Behaviour ◽  
Diglycidyl Ether ◽  
Cross Linking ◽  
Available Water Content ◽  
The Cross ◽  
Poly Ethylene ◽  
Tan Δ

Abstract Highly swellable, mechanically stable hydrogels were obtained by cross-linking different technical lignins with poly(ethylene) glycol diglycidyl ether (PEGDGE). The gelation time and the properties of the products can be controlled by the extent of pre-oxidation and the cross-linking conditions, namely the dynamic viscosity η*, storage and loss modulus (G′; G″), and loss factor tan δ. The highest free swelling capacities (FSC) of up to 50 g water per g xerogel were obtained from pre-oxidized pine kraft lignin Indulin® AT and spruce organosolv lignin. Dynamic rheological measurements confirmed the typical rheological behaviour of gel structures, i.e. a linear decrease of dynamic viscosity about three orders of magnitude within a frequency range of 0.08 and 20 s-1. The results furthermore revealed a good mechanical sturdiness of the cross-linked lignin hydrogels. Sandy soils supplemented with small quantities of the hydrogels were found to feature a significantly increased plant-available water content. Based on the observed effects, oligo(oxyethylene) lignins are promising materials with respect to a prolonged water retention in soils.

Switchover of reactions of solvated electrons with nitrate ions and ammonium ions in propanol–water solvents

1993 ◽  
Vol 71 (9) ◽  
pp. 1297-1302 ◽  
Author(s):  
Tae Bum Kang ◽  
Gordon R. Freeman
Keyword(s):  
Rate Constants ◽  
Pure Water ◽  
Reaction Rates ◽  
Binary Solvents ◽  
Ammonium Ions ◽  
Concentrated Solutions ◽  
Solvated Electrons ◽  
Reaction Rate Constants ◽  
Water Solvent ◽  
Arrhenius Temperature

The reaction rate constants of [Formula: see text] with ammonium nitrate (~ 0.1 mol m−3) in 1-propanol-water and 2-propanol–water binary solvents correspond to [Formula: see text] reaction in the water-rich solvents, and to [Formula: see text] reaction in alcohol-rich solvents. The overall rate constant is smaller in solvents with 40–99 mol% water, with a minimum at 70 mol% water. The Arrhenius temperature coefficient is 26 kJ mol−1 in each pure propanol solvent, increases to 29 kJ mol−1 at 40 mol% water, then decreases to 17 kJ mol−1 in pure water solvent. The high reaction rates in the single component solvents, alcohol or water, are limited mainly by solvent processes related to shear viscosity (diffusion) and dielectric relaxation (dipole reorientation). Rate constants reported for concentrated solutions (50–1000 mol m−3) of ammonium and nitrate salts in methanol (Duplâtre and Jonah. J. Phys. Chem. 95, 897 (1991)) have been quantitatively reinterpreted in terms of the ion atmosphere model.

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