Modified Guar Gum Research Articles

Development of an eco-friendly dust suppressant based on modified guar gum: Performance and mechanism analysis

In order to solve the soil fugitive dust pollution at the infrastructure construction site, a new environment friendly dust suppressant was prepared with carboxymethyl guar gum (CMGG) as the core raw material. The optimal formulation of the dust suppressant was determined using single factor experiments and RSM (Response surface method). The performance test results showed that the water erosion rate of the soil dust was <5%, and wind erosion rate reached 97.51%. The water retention rate of dust suppressant reached 31.33%. The dust suppressant contained substantial oxygen-containing functional groups (-OH, -COOH). The -COOH and -OH contained in the soil were interactively attracted with -OH and -COOH in dust suppressant to form hydrogen bonds, resulting in interfacial between dust suppressant and soil dust surface. The dust suppressant-soil dust adhesion system is formed, thereby inhibiting the spread of soil dust.

Multi-laboratory evaluation of the reproducibility of polymer biodegradation assessments applying standardized and modified respirometry methods

This research evaluated the intra- and interlaboratory variability when applying OECD 301F and OECD 301B Ready Biodegradation respirometric test methods to quantify polymer biodegradation as well as the impact of method modifications including test duration, inoculum level and test substance concentration on results. This assessment synthesizes results of mineralization studies on 5 polymers of varying structural components, molecular weight, charge, and solubility, evaluated at 8 different laboratories in 4 different countries, providing significant geographic variation in inoculum source as well as lab to lab variations in test setup. Across all laboratories, intralaboratory variability was low (≤18 % absolute difference) indicating the reproducibility of results between replicates and uniformity of test setup in each laboratory. Interlaboratory variation was also low for all 5 polymers with extent of mineralization being comparable in all OECD 301F and 301B studies even when test methods were modified. Across all studies mean mineralization was 89 ± 5.5 % for polyethylene glycol 35,000, 85 ± 7.4 % for polyvinyl alcohol 18-88, 44 ± 13 % for carboxymethyl cellulose (DS 0.6), 48 ± 4.1 % for a modified guar gum, and 88 ± 6.2 % for microcrystalline cellulose (MCC) at study completion. Due to the lack of polymeric reference materials, MCC was evaluated and found to be a suitable reference material for polymers that biodegrade rapidly in screening studies. An additional respirometric study was conducted quantifying mineralization of the 5 polymers in river water to evaluate the relationship with OECD 301 results using activated sludge as the inoculum. A similar extent of mineralization was observed for all 5 polymers in the OECD 301 and river water studies but time to reach the maximum extent of mineralization was longer using river water as the inoculum source likely due to the lower microbial counts (106 CFU/L) in the test system.

Preparation of benzenesulfonyl hydrazone modified guar gum and its adsorption properties for dyes and phytotoxicity assays

Herein, a novel environmentally friendly benzenesulfonyl hydrazone modified guar gum (DGH) that carries excellent adsorption performance towards dyes was facilely prepared through oxidation and condensation. The structure, morphology, and physics-chemical of DGH were fully characterized by multiple analysis techniques. The as-prepared adsorbent yielded highly efficient separating performance towards multiple anionic and cation dyes, including CR, MG, and ST with the maximum adsorption capacity of 1065.3839 ± 10.5695, 1256.4467 ± 2.9425, and 1043.8140 ± 0.9789 mg/g at 298.15 K, respectively. The adsorption process well fitted the Langmuir isotherm models and the pseudo-second-order kinetic models. The adsorption thermodynamics revealed that the adsorption of dyes onto DGH was spontaneous and endothermic. The adsorption mechanism indicated that the hydrogen bonding and electrostatic interaction participated in the fast and efficient removal of dyes. Furthermore, the removal efficiency of DGH still remained above 90 % after six adsorption-desorption cycles, and the presence of Na+, Ca2+, and Mg2+ have weakly impacted the removal efficiency of DGH. The phytotoxicity assay was conducted via the germination of mung bean seeds, which confirmed the adsorbent can effectivity decreased the toxicity of dyes. Overall, the modified gum-based multifunctional material has good promising applications for wastewater treatment.

Synthesis of guar gum-g-coconut husk (SnO&lt;SUB align="right"&gt;2-SiO&lt;SUB align="right"&gt;2) nanocomposite for removal of Cu (II) and Cr (VI) from wastewater

A new sorbent material namely 'guar gum-g-coconut husk (SnO2-SiO2) [GG-g-CH(SnO2-SiO2)] nanocomposite' was synthesised by preparation of coconut husk metal oxide nanoparticles and grafted into acrylamide modified guar gum (GG) base with the help of crosslinking agent glutaraldehyde. Its adsorption capacity was evaluated for the adsorption of Cu (II) and Cr (VI) metal ions from wastewater and factors affecting variables such as pH, adsorbent dose, contact time, and concentration were extensively investigated. It was found from the study that the maximum percent removal achieved was 99% for Cu (II) and 92.74% Cr (VI) at a pH of 8.3 and 7.2 respectively with an optimum adsorbent dose of 250 mg/l in 120 mins. The sorption data obeyed both Langmuir and Freundlich isotherms but Freundlich isotherm was better mathematical fit than Langmuir model. The Langmuir sorption capacity (qmax) was found to be 105.26 and 98.03 mg/g for Cu (II) and Cr (VI) respectively. Freundlich constants, KF values obtained for Cu (II) was 1.135 and for Cr (VI) was 1.11 while 1/n values obtained for Cu (II) was 0.647 and for Cr (VI) was 0.656, respectively.

Acylhydrazone-modified guar gum material for the highly effective removal of oily sewage

Oily sewage poses a serious environmental risk normally; thus, herein, the modified guar gum (GG-SH) was prepared through rapid condensation reaction between polysaccharide and stearic hydrazide. GG-SH exhibited high removal efficiency of crude oil, the maximum adsorption capacity was calculated to be 2157.3 mg•g-1. The kinetics and isotherm statistical theories showed that the sorption of crude oil onto GG-SH was governed by pseudo-second-order, and Langmuir models, respectively. The removal rate was still high after six cycles of regeneration, indicating an outstanding technique to prepare polysaccharide-based material for the oily sewage treatment with high efficiency and recyclability.

Modified guar gum: An alternative source for printing of cotton fabric with reactive dye

AbstractThe alginate thickener is the thickener frequently used for reactive printing of textile. The thickener responds with reactive pigments and thus does not lead to the fabric composition becoming stiffer. In this study, we prepared oxidised natural guar gum with hydrogen peroxide, sodium hypochlorite and sodium hydroxide. All other polysaccharides comprise reactive hydroxyl units with a stronger reactivity that must be replaced if they are to be used in reactive printing. Guar derivatives were synthesised and verified using Fourier‐transform infrared (FTIR) spectroscopy. Natural thickeners, synthetic guar gum derivatives, have been employed in textile printing technique. In comparison to other synthetic thickeners, modified environmental guar gum polymer has been shown to be an ecologically friendly and low‐cost thickener. Cotton fabric printed with modified guar thickening with hydrogen peroxide has even stronger colour strength than fabric printed with sodium alginate thickener, which is highly favourable. Penetration properties, colour value, colour strength, colour fastness to washing, light and rubbing was compared with alginate thickener (readily available on the market). Guar gum thickeners showed enhanced features versus sodium alginate for reactive printing. Partially replaced guar gum is an appropriate option due to the colour and physical properties.

Construction of a double-responsive modified guar gum nanoparticles and its application in oral insulin administration

The use of intelligent insulin delivery systems has become more important for treating diabetes. In this study, a dual-responsive oral insulin delivery nanocarrier that responds to glucose and pH has been developed. First, the oleic acid hydrophobic modified guar gum (GG) was synthesized by the esterification reaction, and the γ-polyglutamic acid (γ-PGA) was coupled with GG by the amidation reaction. The obtained pH-responsive copolymer (γ-PGA-GG) was cross-linked by concanavalin A to obtain pH/glucose dual-responsive nanocarriers, and insulin was effectively loaded into the dual-responsive nanocarriers. The insulin-loaded nanoparticles can achieve effective pH and glucose responses, releasing insulin on demand. In vitro and in vivo studies demonstrated the dual-responsive nanoparticles can protect insulin against the pH changes in the digestive tract and deliver insulin into the body to exert a hypoglycemic effect. Moreover, the dual-responsive nanoparticles have significant potential to be employed for oral insulin delivery.

Experimental investigation of natural polysaccharide-based mixed matrix membrane modified with graphene oxide and Pd-nanoparticles for enhanced gas separation performance

In this work, we proposed a mixed matrix membrane prepared by using a glycerol modified guar gum (GGP) polymer matrix incorporated with graphene oxide (GO). The influence of varying GO concentration on the gas separation performance was investigated and 2 wt% was found to be the optimum concentration for high performance. The 2 wt% GO mixed matrix membranes were further modified with Pd nanoparticles. When GO, and Pd nanoparticles were mixed, CO2 permeability increased by 49.94%, while the permeability of H2 gas molecules decreased by 98.11%, respectively, compared to the pristine GGP membrane. The selectivity of CO2/H2 was obtained as 18.27. The glass transition temperature of the membrane increased from 85 to 95.2 °C, tensile strength and elongation of the break were significantly improved by 29.09% and 84.37% through the addition of Pd and GO into the membrane. The scanning electron microscopy revealed a dense top surface after GO nanosheets incorporation. Further, the thermogravimetric analysis proposes that the modified membrane is thermally stable than GGP. Henceforth, the study suggests GO incorporation and Pd nanoparticles modification of guar gum membrane is a promising gas separation membrane with potentially high selectivity for CO2 gas.

Sonochemical and thermal modification of guar gum: A comparative analysis

The goal of this research is to chemically tailor guar gum in order to improve its qualities and uses. Guar gum is a natural polymer containing hydroxyl groups that may be bonded to physiologically active substances, consisting of (1–4)-β-D mannopyranosyl groups coupled with α-d-galactopyranosyl groups at a ratio of 1.5–2. Guar gum is modified by employing thermal and sono-chemical techniques and epichlorohydrin (EP) is used as a crosslinker. The product obtained is characterized with the help of infrared spectroscopy (FT-IR), differential scanning calorimetric (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and swelling analyses. The temperature, at which the reaction is carried out, is an important parameter that affects the properties of the end product obtained. The modified guar gum is stable at high temperatures and can be used in the food and cosmetics industries as a stabiliser or suspending agent, or in the pharmaceutical industry as a binder or sustained-release polymer matrix for tablets or granulations.

Assessment of Anti-microbial and Anti-oxidant Activities of Modified Guar Gum

Apart from drug delivery potential of polysaccharides or their chemical derivatives, some chemically modified polysaccharides particularly sulfated polysaccharides showed significant biological property. In this study, guar gum was sulfated by reacting with various ratios of CSA (chlorosulfonic acid) and pyridine to obtain the product with different degree of sulfation (DS). The sulfated guar gum derivatives were examined by FTIR, NMR and degree of sulfation analysed and were further evaluated for their potential antibacterial activity by agar diffusion method. Results obtained from the study indicated that derivatives having higher degree of sulfation exhibited moderate activity against the selected bacterial strains at 200 µg∙ml − 1 . However, the sulfated guar gum did not show any significant antifungal activity at any concentration studied. The sulfated guar gum demonstrated dose-dependent DPPH and H 2 O 2 scavenging activity with maximum activity noted at 2 mg∙ml − 1 concentration. The sulfation of partially oxidized guar gum caused significant improvement of antioxidant activity to that observed for non-oxidized sulfated guar gum derivative. This study revealed that the extent of sulfation and molecular weight had significant impact on antimicrobial and antioxidant activities of guar gum.

Functionalized polymethyl methacrylate-modified dialdehyde guar gum containing hydrazide groups for effective removal and enrichment of dyes, ion, and oil/water separation

In the study, a novel polymethacryloyl hydrazone modified guar gum adsorption material (GSA) was prepared via condensation between polyhydrazide and dialdehyde guar gum. GSA exhibited an abundant porous structure, higher selectivity for cationic pollutants in high-concentration wastewater like methylene blue (MB), malachite green (MG) dyes, and Cu2+. Under optimized experimental conditions, the maximum equilibrium adsorption capacity of MB, MG, and Cu2+ were 1418.36 mg/g, 1375.58 mg/g, and 196 mg/g, respectively. Adsorption isotherms and kinetics were well fitted with the Langmuir isotherm model and pseudo-second-order kinetic model. The thermodynamic analysis demonstrated that the adsorption process was endothermic, feasible, and spontaneous. Correspondently, the adsorption mechanism was explored by FTIR, SEM-EDS and XPS. The adsorbent was employed in disposing of local sewage water. Additionally, GSA successfully achieves efficient water/oil separation in different salt concentrations with a separation efficiency exceeding 99%.

Chemically modified guar gum and ethyl acrylate composite as a new corrosion inhibitor for reduction in hydrogen evolution and tubular steel corrosion protection in acidic environment

The paper deals with the synthesis of Guar gum and ethyl acrylate (GG-EEA) composite. The synthesized natural polysaccharide composite was used as a corrosion inhibitor to reduce hydrogen evolution and P110 steel corrosion protection in 15% HCl (Hydrochloric acid). The primary corrosion techniques like weight loss, electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization (PDP) was used to analyze the corrosion inhibition process. The PDP proposed that GG-EEA composite is a mixed-type corrosion inhibitor and inhibits corrosion by blocking the active sites presenting over the metal surface. The corrosion inhibition performance of GG alone is 77.5%, and that of GG-EEA is 92.3% at 500 mg/L. The adsorption of GG-EEA onto P110 steel is spontaneous and mixed type, i.e., both physical and chemical. The conformation of GG-EEA molecule adsorption was done using a scanning electron microscope (SEM), Energy dispersive x-ray spectroscopy (EDX), Atomic force microscopy (AFM), and X-ray photoelectron spectroscopy studies. Density functional theory (DFT) analysis was done to explore the active sites over the inhibitor in metal-inhibitor interaction. Molecular dynamic simulation (MD) simulations study reveals that GG-EEA has more adsorption capacity than GG alone.

Hydrophobically modified guar gum films for wound dressing

Hydrophobically modified guar gum (HMG) was prepared by microwave-assisted polycondensation of naturally abundant guar gum (GG) and dimer acid (DA) following green chemistry principles. HMG was blended with polyvinyl alcohol (PVA) along with gentamicin sulphate (a hydrophilic antibacterial drug) or amoxicillin (a hydrophobic antifungal drug) to obtain drug-loaded films. The two films were characterized by FTIR spectroscopy, X-ray diffraction analysis and scanning electron microscopy. Water absorbency, drying time (water holding time) and vertical wicking time were also determined. The results suggest that the drug-loaded films, HMGA with amoxicillin and HMGG with gentamicin sulphate, could retain moisture for 5–7 h and easily absorb wound exudates. Drug release data were analysed using first-order, Higuchi, Hixson–Crowell and Korsmeyer–Peppas kinetic models and reveal that the HMG-based films exhibit good drug delivery efficiency for hydrophobic as well as hydrophilic drugs. The results of agar diffusion method indicate the two films to exhibit significant resistance toward bacterial (Staphylococcus aureus and Escherichia coli) and fungal (Candida albicans) growth. In vivo wound healing studies on Wistar albino rats show almost full wound closure within 15 days. These results demonstrate the HMG-based drug-loaded films to be promising candidates to serve as biodegradable wound dressing.

Rheological behaviours of guar gum derivatives with hydrophobic unsaturated long-chains

Three guar gum derivatives with hydrophobic unsaturated long-chains were successfully synthesized, including oleic guar gum (OGG), linoleic guar gum (LGG) and erucic guar gum (EGG). The guar gum derivatives were characterized by Fourier transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA). Moreover, comparative studies on the rheological behaviours of guar gum (GG) and three guar gum derivatives were performed. Regardless of their hydrophobic side groups, all sample solutions showed the properties of non-Newtonian shear-thinning fluids, and their complex viscosities (η*) increased significantly with increasing concentration. In contrast to GG, OGG or EGG, LGG exhibited the strongest shear-thinning property when the concentration is 1 wt%. It was found that the frequency-dependent viscous (G′′) and elastic modulus (G′) curves of GG and its derivatives aqueous solutions cross at a specific frequency. This crossover frequency decreases with increasing sample concentration, indicating that the viscoelasticity is highly dependent on polymer concentration. In addition, when the molar substitution (MS) of the repeating sugar units in the guar gum derivatives is less than 0.08, the LGG solution showed more obvious solid-like rheological properties than the OGG and EGG solutions at the same concentration.

Synthesis of hydrophobically modified guar gum film for packaging materials

Guar gum was hydrophobically modified by microwave assisted condensation with dimer acid (DA, a dimer of ricinoleic acid derived from castor oil) under “green” conditions. The condensation product (HMG) was then blended with polyvinyl alcohol and cast into films abbreviated as HMGF (hydrophobically modified guar gum film). FTIR and UV–visible spectroscopies, X-ray diffractometry, swelling, permeability and tensile strength measurements were used to evaluate the properties of HMG and HMGF. HMGF exhibits optimal mechanical strength with UV protective effect and restricted entry of chemical contaminants. HMGF could be easily disposed by burying in soil. HMGF may be a potential eco-friendly food packaging material.

Polymer-Assisted In Situ Synthesis of Silver Nanoparticles with Epigallocatechin Gallate (EGCG) Impregnated Wound Patch Potentiate Controlled Inflammatory Responses for Brisk Wound Healing.

IntroductionAn ideal wound dressing material needs to be predisposed with desirable attributes like anti-infective effect, skin hydration balance, adequate porosity and elasticity, high mechanical strength, low wound surface adherence, and enhanced tissue regeneration capability. In this work, we have synthesized hydrogel-based wound patches having antibacterial silver nanoparticles and antioxidant epigallocatechin gallate (EGCG) and showed fast wound closure through their synergistic interaction without any inherent toxicity.Methods and resultsWound patches were synthesized from modified guar gum polymer and assessed to determine accelerated wound healing. The modified polymer beget chemical-free in-situ synthesis of monodispersed silver NPs (~12 nm), an antimicrobial agent, besides lending ionic surface charges. EGCG impregnated during ionotropic gelation process amplified the efficacy of wound patches that possess apt tensile strength, porosity, and swellability for absorbing wound exudates. Further, in vitro studies endorsed them as non-cytotoxic and the post agent effect following exposure to the patch showed an unbiased response to E coli K12 and B. subtilis. In vivo study using sub-cutaneous wounds in Wistar rats validated its accelerated healing properties when compared to a commercially available wound dressing material (skin graft; Neuskin-F®) through better wound contraction, promoted collagen deposition and enhanced vascularization of wound region by modulating growth factors and inflammatory cytokines.ConclusionSynthesized wound patches showed all the desired attributes of a clinically effective dressing material and the results were validated in various in vitro and in vivo assays.

Synthesis of hydrazine-grafted guar gum material for the highly effective removal of organic dyes

The galacylhydrazine modified guar gum (GG-GH) was prepared through oxidation and condensation. GG-GH demonstrated highly efficient removing performance for organic dyes in large volume of water sample solutions, a rapid uptake of dyes was observed and the equilibrium is achieved in 0.5 h. The maximum adsorption capacity for MB, RhB, MeO and BrB were 1522.2 mg g−1, 1359.96 mg g−1, 868.83 mg g−1and 904.7 mg g−1 at room temperature according to the Langmuir adsorption isotherm(R2 > 0.977). The removal percentage still remains high(>95%) after ten filtration-regeneration cycles, suggesting GG-GH is an excellent gum-based materials for the water treatment with high recyclability and long life.

Performance of Negative Lithium Titanate Electrodes Containing Minimized Amounts of Conducting Polymer and Modified Guar Gum as Binder

Negative electrodes for lithium ion batteries based on lithium titanate were prepared with minimized weight fractions of a water based binder composed of poly-3,4-ethylenedioxythiopene:polystyrene sulfonate, modified guar gum and carbon black. The electrode material was characterized in two-electrode button test cells with cyclic voltammetry, galvanostatic charge/discharge and impedance measurements. In comparison to electrodes prepared with poly(vinylidenedifluoride) as a binder superior performance in terms of specific storage capability, rate capability and stability was noticed, experimental observations, in particular changes during extended cycling, could be rationalized consistently with the applied experimental methods.

RESEARCH AND DEVELOPMENT OF DIAZEPAM SOLID DISPERSION POWDER USING NATURAL POLYMERS

Objective: The objective of this study was to enhance the solubility and dissolution rate of a poorly water-soluble drug by solid dispersion (SD) technique, in order to conduct an investigation of the effect of these natural hydrophilic polymers on release mechanism from SD.Methods: The SD of diazepam (DZM) were prepared by using modified sodium alginate (SA) and modified guar gum (GG) in different drug: polymer ratios (1:1 and 1:2) by using physical mixture method (PM) and fusion method (FM). Further, the formulations were characterized for calibration curve, Fourier transforms infrared spectroscopy (FTIR) studies, % age practical yield, drug content estimation, solubility studies, dissolution studies.Results: The pure drug and SD were characterized by pre and post-formulations studies. The %age practical yield ranged from 92.9±0.25 to 49±0.57%, and the drug content estimation ranged from 99.34±0.40 to 65.25±0.25 %. The FTIR studies shown that the compatibility between pure drug and natural polymers was stable. All the SD showed improved solubility as compared to the pure drug (PD). SD prepared with modified SA (1:2) by PM and FM shown the huge enhancement of solubility and dissolution rate of the DZM. This can be specific to the improvement in wettability and dispersibility, as well as enhances the drug amorphous fraction.Conclusion: On the basis of the research study, the SD technique shows the enhancement in the solubility of poorly water-soluble drug using natural polymers. SD containing natural polymers prepared with PM and FM shown the remarkable improvement in the release outline compared with PD, DZM.

Preparation and experimental dust suppression performance characterization of a novel guar gum-modification-based environmentally-friendly degradable dust suppressant

To address the coal dust pollution issue associated with coal mines and further improve the dust suppression performance of dust suppressants, the present study first uses Guar gum (GG), a widely available pollution-free natural polymer, as the main ingredient to produce modified Guar gum -GGTCS by chemically modifying its –OH functional group, followed by employing infrared spectroscopy and thermogravimetric analysis to characterize the chemical structure and thermal stability of GG and its modified product GGTCS; subsequently, the modified product GGTCS is used as the primary raw material, which is mixed with certain wetting and water retention agents so as to develop an environmentally-friendly degradable dust suppressant with decent dust suppression performance. The optimal formula for preparing this environmentally-friendly dust suppressant is determined as: 0.8% GGTCS +1.5% glycerol (GLY) + 0.1% sodium dodecyl benzene sulfonate (SDBS) + 0.02% fatty alcohol polyoxyethylene ether (AEO); the high-resolution Scanning Electron Microscopy (SEM) is employed to observe the solidified film on the coal powder surface before and after the treatment of dust suppressant. A digital display electronic universal testing machine is adopted to measure the maximum pressure the solidified film can withstand before being crushed (29 kPa), and a test is run to assess the degradability of the newly developed degradable dust suppressant. The test results indicate that the newly developed hybrid dust suppressant has decent water retention, hardening, cementing, anti-compression, and degradability characteristics, which can offer significant economic, environmental, and social benefits to the dust control field.