scholarly journals Chemical Modification on Reactive Dye Adsorption Capacity of Castor Seeds

2011 ◽  
Vol 8 (s1) ◽  
pp. S335-S343 ◽  
Author(s):  
V. Dharmalingam ◽  
A. K. Ramasamy ◽  
V. Balasuramanian
Keyword(s):  
Functional Groups ◽  
Functional Group ◽  
Dye Adsorption ◽  
Reactive Dye ◽  
Neutral Red ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Anionic Dyes ◽  
Cresyl Blue ◽  
Castor Seeds

Abstract: The roles played by four major functional groups (amine, carboxyl, azo, hydroxyl groups) in the biomass of castor seeds in adsorption of seven dyes were investigated. These functional groups in castor seeds were chemically modified individually to determine their contribution to the adsorption of ionic dyes. The dyes used were remazol red B, procino yellow, fast green FCF, brilliant cresyl blue, methylene blue, neutral red, red-141. It was found that hydroxyl group inhibited the adsorption of anionic dyes but it was major functional group in the adsorption of cationic dyes, hydroxyl group was important functional group in the adsorption of all seven dyes and the effect of methylation of amino group was not significant on the adsorption of seven dyes.

scholarly journals Modification of cotton fabrics with 2-diethylaminoethyl chloride for salt-free dyeing with anionic dyes

Cellulose ◽  
2021 ◽  
Author(s):  
Peixin Tang ◽  
Leilah-Marie E. Lockett ◽  
Mengxiao Zhang ◽  
Gang Sun
Keyword(s):  
Electrostatic Interactions ◽  
Light Exposure ◽  
Dye Adsorption ◽  
Cost Effective ◽  
Cotton Fabrics ◽  
Cotton Cellulose ◽  
Hydroxyl Groups ◽  
Anionic Dyes ◽  
Free System ◽  
Untreated Cotton

AbstractA chemical modification of cotton fabrics by 2-diethylaminoethyl chloride (DEAE-Cl) was achieved, and the resulted cotton fabrics demonstrated salt-free dyeing properties with anionic dyes. Nucleophilic property of hydroxyl groups in cotton cellulose was enhanced under alkaline conditions and could react with DEAE-Cl, a chemical possessing both nucleophilic and electrophilic sites. The monolayered DEAE-grafted cotton cellulose could further react with DEAE-Cl to form multiple cationic quaternary ammonium salts (denoted as DEAE@Cotton), which are highly interactive with anionic dye molecules. The strong electrostatic interactions between the DEAE@Cotton and the dyes eliminated the use of inorganic salts in cotton dyeing process. The chemical structure and property of DEAE@Cotton were characterized and compared with untreated cotton. The DEAE@Cotton can be dyed in a salt-free system, and the dye exhaustion was faster than the conventional dyeing method due to the robust electrostatic interactions of the fabrics with anionic dyes. The dyed fabrics demonstrated outstanding color fastness under repeated washing, light exposure, and crocking. The dye adsorption process on DEAE@Cotton follows Langmuir isotherm model (R2 = 0.9667). The mechanism of enhanced dyeability was experimentally proved by treating the fabric with other anionic dyes in a salt-free system, proving the process to be environmentally friendly and cost-effective. Graphic abstract

Immobilization of enzymes introducing spacers. A synthesis of carriers with spacers of various length

1983 ◽  
Vol 48 (1) ◽  
pp. 184-191 ◽  
Author(s):  
Christian Flemming ◽  
Anton Gabert ◽  
Helmut Wand ◽  
Jiří Zemek
Keyword(s):  
Functional Groups ◽  
Succinic Anhydride ◽  
Functional Group ◽  
Dicarboxylic Acids ◽  
Hydroxyl Group ◽  
Optimum Length ◽  
Stepwise Synthesis ◽  
Immobilization Of Enzymes ◽  
Molecular Substances ◽  
Molecular Compounds

A synthesis of spacers of various length and type, utilizing α,ω-dicarboxylic acids, α,ω-diaminoalkanes and succinic anhydride, condensation with carbodiimide, or introduction of -NCS functional groups is described. Carriers with a spacer were prepared by a method of binding the already synthesized spacer to the carrier (glass), and alternatively, by a stepwise synthesis of the spacer on the carrier surface. Carriers containing functional groups (37.2 - 39.3 μmol/g - NCS and 25 - 41.5 μmol/g - COOH) prepared in this way had total length of the spacer 0.62 - 3.92 nm. Whereas the length of the spacer is if no substantial importance for the reaction with low-molecular substances (L-valine, L-cysteine and 2-mercaptoethanol), the optimum length of the spacer for high-molecular compounds (albumin) is about 1.75 - 2.05 nm. The hydroxyl group adjacent to the functional group of the spacer (1,3-diaminopropan-2-ol) is also of noticeable influence.

Modifications of Hydroxyl-Functionalized HEA/HEMA and Their Polymers in the Synthesis of Functional and Graft Copolymers

2017 ◽  
Vol 14 (6) ◽  
pp. 798-809 ◽  
Author(s):  
Dorota Neugebauer
Keyword(s):  
Functional Groups ◽  
High Performance ◽  
Functional Materials ◽  
Functional Polymers ◽  
Functionalized Polymers ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Hydroxyethyl Methacrylate ◽  
Protective Groups ◽  
Biomedical Field

Background: Functional groups have played a fundamental role in synthesis of polymers due to they decide about polymerization methods, and influence on their topologies, properties and applications. The functional polymers are used as a high-performance materials with well-adjusted properties by modification of functionalities that can be addressed selectively to a variety of applications, usually in biomedical field. Objective: In this minireview article hydroxy-functionalized polymers, mostly based on 2-hydroxyethyl methacrylate (HEMA) or 2-hydroxyethyl acrylate (HEA), are discussed as products of the controlled polymerizations and as substrates in the functionalization reactions. Conclusion: The hydroxyl group gives opportunity for prepolymerization reactions, including protection group and macromonomer preparation. Multifunctional (co)polymers of HEMA/HEA contain reactive hydroxyl groups, which are directly accessible or caring suitable protective groups that can be removed or/and modified by post-polymerization reactions. The variation of approaches let to obtain functional polymers with linear, star-shape and graft topologies as the well-defined structures for the advanced functional materials, including smart polymeric devices.

scholarly journals Preparation of Sulfonated Poly(arylene ether nitrile)-Based Adsorbent as a Highly Selective and Efficient Adsorbent for Cationic Dyes

Polymers ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 32 ◽  
Author(s):  
Xuefei Zhou ◽  
Penglun Zheng ◽  
Lingling Wang ◽  
Xiaobo Liu
Keyword(s):  
Dye Adsorption ◽  
Neutral Red ◽  
Water Soluble ◽  
Cationic Dyes ◽  
Maximum Adsorption Capacity ◽  
Anionic Dyes ◽  
Adsorption Selectivity ◽  
Distinct Structure ◽  
Arylene Ether ◽  
Sulfonated Poly

In this work, a highly selective and efficient polymer adsorbent inspired by a water-soluble sulfonated poly(arylene ether nitrile) (SPEN) was successfully synthesized. Due to the distinct structure of functional carboxyl, sulfonic acid and rigid benzene rings, a facile aluminium (III) ions crosslinking method was employed to fabricate the SPEN-based adsorbents (SPEN-Al). Among the three adsorbents, SPEN-Al-2 exhibited superior adsorption capacities with uniform morphology. Subsequently, the SPEN-Al-2 was selected as the adsorbent for three cationic dyes (rhodamine B (Rh B), neutral red (NR), methylene blue (MB)) and three anionic dyes (orange G (OG), methyl orange (MO), acid fuchsin (AF)), respectively, demonstrating that the adsorbent possessing excellent selectivity toward cationic dyes. Moreover, the dye’s adsorption selectivity of SPEN-Al-2 was further certificated in a binary cationic-anionic dyes mixtures (MB/OG and MB/MO) system. Taking MB as a dye model, a series of factors (contact time, concentration, temperature and pH) and adsorption models were systematically investigated in dye adsorption experiments. Results indicated that the adsorption was endothermic and the maximum adsorption capacity of SPEN-Al-2 could reach up to 877.5 mg/g; pseudo-second-model and Langmuir model were fitted to the adsorption kinetics and equilibrium isotherm, respectively, manifesting that SPEN-Al adsorbent was promising in the dyes removing field.

scholarly journals Preparation of Graphite Oxide Containing Different Oxygen-Containing Functional Groups and the Study of Ammonia Gas Sensitivity

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3745 ◽  
Author(s):  
Liming Luo ◽  
Tongjiang Peng ◽  
Mingliang Yuan ◽  
Hongjuan Sun ◽  
Shichan Dai ◽  
...  
Keyword(s):  
Moisture Content ◽  
Functional Groups ◽  
Reaction Temperature ◽  
Graphite Oxide ◽  
Photoelectron Spectroscopy ◽  
Raw Material ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Gas Sensitivity ◽  
X Ray

A series of graphite oxide samples were prepared using the modified Hummers method. Flake graphite was used as the raw material and the reaction temperature of the aqueous solution was changed (0 °C, 30 °C, 50 °C, 60 °C, 70 °C, 80 °C, and 100 °C). X-ray diffraction, Fourier-transform infrared spectroscopy, Raman spectral analysis, X-ray photoelectron spectroscopy, and contact angle tests were performed to characterize the structure, chemical bonding, type, and content of oxygen-containing functional groups of the graphite oxide samples. The results showed that the type and content of each oxygen-containing functional group could be controlled by changing the reaction temperature with the addition of water. As the temperature of the system increased, the degree of oxidation of the graphite oxide samples first increased and then decreased. Too high a temperature (100 °C) of the system led to the formation of epoxy groups by the decomposition of some hydroxyl groups in the samples, causing the reduction of oxygen-containing functional groups between the graphite layers, poor hydrophilic properties, and low moisture content. When the system temperature was 50 °C, the interlayer spacing of the graphite oxide samples was at its highest, the graphite was completely oxidized (C/O = 1.85), and the oxygen-containing functional groups were mainly composed of hydroxyl groups (accounting for approximately 28.88% of the total oxygen-containing functional groups). The high content of hydroxyl and carboxyl groups had good hydrophilic ability and showed the highest moisture content. The sample at 50 °C had better sensitivity to ammonia because of its high hydroxyl group and carboxyl group content, with the sample showing an excellent profile when the ammonia concentration was 20–60 ppm.

scholarly journals Galloylglucoses of low molecular weight as mordant in electron microscopy. II. The moiety and functional groups possibly involved in the mordanting effect.

1976 ◽  
Vol 70 (3) ◽  
pp. 622-633 ◽  
Author(s):  
N Simionescu ◽  
M Simionescu
Keyword(s):  
Molecular Weight ◽  
Gallic Acid ◽  
Functional Groups ◽  
Hydroxyl Group ◽  
Cross Linking ◽  
Low Molecular Weight ◽  
Hydroxyl Groups ◽  
Benzoic Acid Derivatives ◽  
Hydrolysis Products ◽  
Intact Molecule

Synthetic pentamonogalloylglucose applied to fixed tissues acts as a mordant, inducing high and diversified contrast similar to that obtained with natural gallotannins of low molecular weight (LMGG). By the separate use of each of the two moieties of the galloylglucose molecule, it was found that gallic acid is the mordanting agent. Glucose may contribute, however, to the effect by increasing the solubility and cross-linking potential of the compound, since the mordanting induced by gallic acid alone is weaker than that produced by its hexose esters. As suggested by results obtained with various phenolics and benzoic acid derivatives, the functional groups required for the mordanting effect of such agents are the carboxyl group, and at least one hydroxyl group concomitantly present on the benzene ring. In the case of galloylglucoses, it is assumed that the effect is due to hydrolysis products (gallic, digallic, or trigallic acids) or to the multiple hydroxyl groups of the intact molecule. Esters of gallic acid (propyl- and methylgallate), as well as pyrogallol, produce a "reversed staining" of all membranes, except for those of communicating (gap) junctions.

scholarly journals Preparation and dye adsorption properties of an oxygen-rich porous organic polymer

RSC Advances ◽  
2021 ◽  
Vol 11 (26) ◽  
pp. 15921-15926
Author(s):  
Guang Yang ◽  
Huimin Gao ◽  
Qingyin Li ◽  
Shijie Ren
Keyword(s):  
Functional Groups ◽  
Dye Adsorption ◽  
Adsorption Properties ◽  
Porous Polymer ◽  
Organic Polymer ◽  
Hydroxyl Groups ◽  
High Porosity ◽  
Porous Organic Polymer ◽  
Adsorption Performance ◽  
Polar Functional Groups

An oxygen-rich porous polymer containing polar carbonyl and hydroxyl groups, POP-O, was prepared, and the combination of abundant polar functional groups and high porosity endows POP-O with decent dye adsorption performance.

scholarly journals Reactivity of Aliphatic and Phenolic Hydroxyl Groups in Kraft Lignin towards 4,4′ MDI

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2131
Author(s):  
Leonardo Dalseno Antonino ◽  
Júlia Rocha Gouveia ◽  
Rogério Ramos de Sousa Júnior ◽  
Guilherme Elias Saltarelli Garcia ◽  
Luara Carneiro Gobbo ◽  
...  
Keyword(s):  
Experimental Work ◽  
Chemical Structure ◽  
31P Nmr ◽  
Kraft Lignin ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Diphenylmethane Diisocyanate ◽  
Complex Chemical ◽  
Heterogeneous Reactivity ◽  
Phenolic Hydroxyl Groups

Several efforts have been dedicated to the development of lignin-based polyurethanes (PU) in recent years. The low and heterogeneous reactivity of lignin hydroxyl groups towards diisocyanates, arising from their highly complex chemical structure, limits the application of this biopolymer in PU synthesis. Besides the well-known differences in the reactivity of aliphatic and aromatic hydroxyl groups, experimental work in which the reactivity of both types of hydroxyl, especially the aromatic ones present in syringyl (S-unit), guaiacyl (G-unit), and p-hydroxyphenyl (H-unit) building units are considered and compared, is still lacking in the literature. In this work, the hydroxyl reactivity of two kraft lignin grades towards 4,4′-diphenylmethane diisocyanate (MDI) was investigated. 31P NMR allowed the monitoring of the reactivity of each hydroxyl group in the lignin structure. FTIR spectra revealed the evolution of peaks related to hydroxyl consumption and urethane formation. These results might support new PU developments, including the use of unmodified lignin and the synthesis of MDI-functionalized biopolymers or prepolymers.

scholarly journals Mechanical Properties of Graphene Oxide Coupled by Multi-Physical Field: Grain Boundaries and Functional Groups

Crystals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 62
Author(s):  
Xu Xu ◽  
Zeping Zhang ◽  
Wenjuan Yao
Keyword(s):  
Mechanical Properties ◽  
Graphene Oxide ◽  
Grain Boundaries ◽  
Functional Groups ◽  
Oxygen Content ◽  
Tensile Fracture ◽  
Hydroxyl Groups ◽  
Molecular Configuration ◽  
Spatial Design ◽  
Out Of Plane

Graphene and graphene oxide (GO) usually have grain boundaries (GBs) in the process of synthesis and preparation. Here, we “attach” GBs into GO, a new molecular configuration i.e., polycrystalline graphene oxide (PGO) is proposed. This paper aims to provide an insight into the stability and mechanical properties of PGO by using the molecular dynamics method. For this purpose, the “bottom-up” multi-structure-spatial design performance of PGO and the physical mechanism associated with the spatial structure in mixed dimensions (combination of sp2 and sp3) were studied. Also, the effect of defect coupling (GBs and functional groups) on the mechanical properties was revealed. Our results demonstrate that the existence of the GBs reduces the mechanical properties of PGO and show an “induction” role during the tensile fracture process. The presence of functional groups converts in-plane sp2 carbon atoms into out-of-plane sp3 hybrid carbons, causing uneven stress distribution. Moreover, the mechanical characteristics of PGO are very sensitive to the oxygen content of functional groups, which decrease with the increase of oxygen content. The weakening degree of epoxy groups is slightly greater than that of hydroxyl groups. Finally, we find that the mechanical properties of PGO will fall to the lowest values due to the defect coupling amplification mechanism when the functional groups are distributed at GBs.

scholarly journals Enhancement of Antioxidant and Hydrophobic Properties of Alginate via Aromatic Derivatization: Preparation, Characterization, and Evaluation

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2575
Author(s):  
Smaher M. Elbayomi ◽  
Haili Wang ◽  
Tamer M. Tamer ◽  
Yezi You
Keyword(s):  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Benzoyl Group ◽  
Antioxidant Evaluation ◽  
Thermo Stability

The preparation of bioactive polymeric molecules requires the attention of scientists as it has a potential function in biomedical applications. In the current study, functional substitution of alginate with a benzoyl group was prepared via coupling its hydroxyl group with benzoyl chloride. Fourier transform infrared spectroscopy indicated the characteristic peaks of aromatic C=C in alginate derivative at 1431 cm−1. HNMR analysis demonstrated the aromatic protons at 7.5 ppm assigned to benzoyl groups attached to alginate hydroxyl groups. Wetting analysis showed a decrease in hydrophilicity in the new alginate derivative. Differential scanning calorimetry and thermal gravimetric analysis showed that the designed aromatic alginate derivative demonstrated higher thermo-stability than alginates. The aromatic alginate derivative displayed high anti-inflammatory properties compared to alginate. Finally, the in vitro antioxidant evaluation of the aromatic alginate derivative showed a significant increase in free radical scavenging activity compared to neat alginate against DPPH (2,2-diphenyll-picrylhydrazyl) and ABTS free radicals. The obtained results proposed that the new alginate derivative could be employed for gene and drug delivery applications.

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