scholarly journals A Novel Hydrogel Based on Renewable Materials for Agricultural Application

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Silvie Durpekova ◽  
Kateryna Filatova ◽  
Jaroslav Cisar ◽  
Alena Ronzova ◽  
Erika Kutalkova ◽  
...  
Keyword(s):  
Citric Acid ◽  
Water Uptake ◽  
Agricultural Product ◽  
Cellulose Derivatives ◽  
Gravimetric Analysis ◽  
Renewable Materials ◽  
Swelling Properties ◽  
Arable Farming ◽  
Swelling Capacity ◽  
The Stability

This study details the design and characterization of a new, biodegradable, and renewable whey/cellulose-based hydrogel (i.e., agricultural hydrogel). This was formulated from cellulose derivatives (carboxymethylcellulose (CMC) and hydroxyethylcellulose (HEC)) and acid whey cross-linked with citric acid, with the aim to obtain an agricultural product with a high swelling capacity to uphold the quality of soil and conserve water resources. With regard to the swelling behaviour of the prepared hydrogels, the authors initially assessed the swelling ratio and capacity for water uptake. Evaluating the chemical structure of the hydrogel and its thermal and viscoelastic properties involved performing Fourier transform infrared spectroscopy, differential scanning colorimetry, thermal gravimetric analysis, and rheological measurement of the hydrogel films. According to preliminary results, sufficient swelling capacity and stiffness were observed in a hydrogel prepared with 3% CMC and HEC, cross-linked with 5% citric acid. Moreover, the kinetics of water uptake revealed a promising capacity that was sustainable after 5 drying and swelling cycles. The results confirmed that the stability of the hydrogel was enhanced by the presence of the citric acid. As a consequence, it is necessary to utilize an appropriate cross-linking concentration and abide by certain conditions to ensure the swelling properties of the prepared hydrogel are sufficient. Further investigation of the topic, especially in relation to applications in soil, could confirm if the whey-cellulose-based hydrogel is actually suitable for agricultural use, thereby contributing to the advancement of sustainable arable farming.

scholarly journals Swelling Properties and Permeability of GMZ Bentonite-Sand Mixtures during Different Solutions Infiltration

2021 ◽  
Vol 13 (4) ◽  
pp. 1622
Author(s):  
Yu-Ping Wang ◽  
Zhe Wang ◽  
Yu Zhao ◽  
Fa-Cheng Yi ◽  
Bao-Long Zhu
Keyword(s):  
Swelling Pressure ◽  
Development Stage ◽  
Gmz Bentonite ◽  
Test Results ◽  
X Ray Diffraction ◽  
Swelling Properties ◽  
Swelling Capacity ◽  
Slow Expansion ◽  
Expansion Stage ◽  
Chemical Solutions

In China, Gaomiaozi (GMZ) bentonite is recognized as a barrier material for isolating nuclear waste. Different chemical solutions may change the hydraulic conductivity and swelling capacity of bentonite. Consequently, a series of swelling pressure and permeability experiments was carried out on bentonite-sand mixtures with various dry densities and infiltrating solutions. X-ray diffraction (XRD) and the field emission scanning electron microscope (FESEM) were carried out on the samples experiencing the tests to identify the influence of chemistry pore solutions upon the mineralogical and microstructure changes. The results show that the swelling pressure experienced rapid swelling, slow expansion, and the stable expansion stage for the specimens of infiltrating solutions except for NaOH. For the specimens infiltrated with NaOH solutions, the swelling pressure experienced rapid increases, slow decreases, and a stable development stage. With hyper-alkaline and hyper-salinity infiltration, the swelling pressure decreased, and the permeability increased. In addition, swelling pressure attained stability more quickly on contact with hyper-alkaline and hyper-salinity solutions. Comparing the test results, the results indicate that the influence of NaOH on the expansion and permeability was higher than NaCl-Na2SO4 at the same concentration.

Extraction Process of Amaranthine Pigment Keeping the Water Wax Fuit Biological Active

2013 ◽  
Vol 295-298 ◽  
pp. 150-154
Author(s):  
Feng Jie Wang ◽  
Xin Qiao Dong ◽  
Xiao Liu
Keyword(s):  
Citric Acid ◽  
Extraction Method ◽  
Raw Materials ◽  
Extraction Process ◽  
Extraction Yield ◽  
Extraction Temperature ◽  
Natural Pigment ◽  
Pigment Extraction ◽  
Acid Aqueous Solution ◽  
The Stability

Development natural pigment retained a variety of nutrition composition is extremely research value.Water Wax Trees Fruit was as raw materials,citric acid aqueous solution was as extracting agent.Amaranthine pigment extraction method were studied on fully grasping the stability of the natural amaranthine pigment and no damage to the water wax fruit biological activity.The effect of extraction yield were studied on Water Wax Trees Fruit natural amaranthine pigment.The results show that the better extraction conditions are extraction temperature at 70 °C, extraction time for 3h,citric acid concentration1.0 % , the material/liquid ration(g/ml) 1:5.The extraction yield is 2.95%.Ultraviolet absorption maximum wavelength is 280 nm.

scholarly journals Plastic composites made from glycerol, citric acid, and forest components

BioResources ◽  
2018 ◽  
Vol 13 (3) ◽  
pp. 6600-6612
Author(s):  
Rasika L. Kudahettige-Nilsson ◽  
Henrik Ullsten ◽  
Gunnar Henriksson
Keyword(s):  
Citric Acid ◽  
Maximum Stress ◽  
Plastic Material ◽  
Ash Content ◽  
Wood Powder ◽  
Renewable Materials ◽  
Amorphous Cellulose ◽  
Mechanical Pulp ◽  
3D Printers ◽  
Absorption Level

An ecofriendly approach for the synthesis of plastic biomaterials based on renewable materials suitable for 3D printing application or other applications has been developed. The material was prepared from native (microcrystalline) or amorphous cellulose, citric acid, and glycerol or ethylene glycol, by a pretreatment at 40 °C and a curing at 175 °C for 1 h. The results showed that tensile properties and the water absorption level of the material were acceptable. The highest strain at break (14%) was obtained from materials made of 10% amorphous cellulose with 90% glycerol/citric acid. It had a maximum stress at 37 MPa. Moreover, materials were without ash content. Possible applications of the material in 3D-printers were discussed. In addition, application of mechanical pulp and wood powder into novel plastic material production was discussed. Foaming during curing might be a problem for this type of material, but this can be avoided by using amorphous cellulose in the recipe.

scholarly journals Radiation-induced Grafting of Styrene onto Polyethylene Films for Preparation of Cation Exchange Membranes: Effect of Crosslinking+

2017 ◽  
Vol 2 (1) ◽  
Author(s):  
M. M. Nasef ◽  
H. Saidi ◽  
A. H. Yahaya
Keyword(s):  
Cation Exchange ◽  
Chemical Properties ◽  
Exchange Capacity ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Swelling Properties ◽  
Ion Exchange Capacity ◽  
Physico Chemical ◽  
Styrene Divinylbenzene ◽  
Radiation Induced

Crosslinked cation exchange membranes bearing sulfonic acid groups (PE-g-PSSA/DVB) were prepared by radiationinduced grafting of styrene/divinylbenzene (DVB) mixtures onto low density polyethylene (PE) films followed by sulfonation reactions. The effect of addition of DVB (2 and 4%) on the grafting behavior and the physico-chemical properties of the membranes such as ion exchange capacity, swelling and ionic conductivity were evaluated incorrelation with grafting yield (Y%). The structural and thermal properties of the membranes were also studied using differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA), respectively. Crosslinking with DVB was found to considerably affect the properties of the membranes in a way that reduces the swelling properties and enhances the chemical stability. The ion conductivity of the crosslinked membranes recorded a level of 10–2 S/cm at sufficient grafting yield (28%) despite the reduction caused by the formation of crosslinking structure. The results of this work suggest that membranes prepared in this study are potential alternatives for various electrochemical applications.

Synthesis, Applications and Swelling Properties of Poly (Sodium Acrylate-Coacrylamide) Based Superabsorbent Hydrogels

2019 ◽  
Vol 41 (4) ◽  
pp. 668-668
Author(s):  
Saud Hashmi Saud Hashmi ◽  
Saad Nadeem Saad Nadeem ◽  
Zahoor Awan Zahoor Awan ◽  
Adeel ur Rehman Adeel ur Rehman ◽  
Ahsan Abdul Ghani Ahsan Abdul Ghani
Keyword(s):  
Rate Constant ◽  
Polymeric Materials ◽  
Water Soluble ◽  
Ion Concentration ◽  
Copolymer Composition ◽  
Swelling Properties ◽  
Swelling Capacity ◽  
Swelling Rate ◽  
Crosslinker Concentration ◽  
Superabsorbent Hydrogels

Superabsorbent hydrogels constitute a group of polymeric materials with three-dimensional network structure, which can swell to absorb an enormous amount of water or aqueous solutions. This property enables various commercial applications of hydrogels such as water holding capability in agriculture and superabsorbent material for baby diapers. Several novel superabsorbent hydrogels based on acrylic acid-co-acrylamide copolymers were synthesized under variation of copolymer compositions through free radical polymerization. N,N’methylenebisacrylamide (MBA) was used as a water soluble crosslinker and potassium persulphate (KPS) as an initiator. Effect of varying the copolymer composition, change in crosslinker concentration, and effect of environmental parameters (pH, temperature, and ion concentration) on both swelling capacity and swelling rate were examined. These gel shows maximum swelling at neutral pH-7, whereas increasing salt concentration in water decrease the swelling capacity. It was found interesting that an increase in crosslinker concentration from 0.020% to 0.16%, the swelling capacity decreases up to 70% while the swelling rate increases from 0.007g water/g dry hydrogel sec to 0.024g water/g dry hydrogel sec, respectively because there is a compromise exists between entropic spring forces between network connection points and the hydrostatic pressure of the water diffusing into the gels. Dynamic swelling curve obtained were fitted to the three different kinetic models namely Peleg’s kinetic model, pseudo 1st order as proposed by Lagergen and pseudo 2nd order kinetics. All these models provided a good agreement with the experimental data; However on the bases of statistical parameters (RMSE, R2 and X2) the Peleg’s model was selected as the most appropriate model for this study. Analyzing rate constant for Peleg’s models at different swelling temperatures disclosed that increasing temperature could only increase the swelling rate without affecting the swelling capacity of the hydrogels. Experimental values for rate constant k1 of Peleg’s model at different temperature shows a sharp decrease from 0.57545 at 30 oC to 0.1535 at 75 oC that contemplated the rate of swelling at 75 oC was 65% faster than that of 30 oC. The diffusion mechanisms in hydrogels were proven to be tailorable by increasing cross-linker concentration and temperature, leading towards the Fickian type diffusion behavior. The synthesized superabsorbent hydrogels were also tested for water retention applications in agriculture.

scholarly journals Phytochemical Molecules from the Decarboxylation of Gomphrenins in Violet Gomphrena globosa L.—Floral Infusions from Functional Food

2020 ◽  
Vol 21 (22) ◽  
pp. 8834
Author(s):  
Natalia Drobnicka ◽  
Katarzyna Sutor ◽  
Agnieszka Kumorkiewicz-Jamro ◽  
Aneta Spórna-Kucab ◽  
Michał Antonik ◽  
...  
Keyword(s):  
Citric Acid ◽  
High Resolution Mass Spectrometry ◽  
Potential Health ◽  
Gomphrena Globosa ◽  
Brewing Process ◽  
Health Promoting ◽  
The Stability ◽  
Kinetics Of ◽  
Derivatives Of

Herein, the generation of decarboxylated derivatives of gomphrenin pigments exhibiting potential health-promoting properties and the kinetics of their extraction during tea brewing from the purple flowers of Gomphrena globosa L. in aqueous and aqueous citric acid solutions were investigated. Time-dependent concentration monitoring of natural gomphrenins and their tentative identification was carried out by LC-DAD-ESI-MS/MS. The high content of acylated gomphrenins and their principal decarboxylation products, 2-, 15-, 17-decarboxy-gomphrenins, along with minor levels of their bidecarboxylated derivatives, were reported in the infusions. The identification was supported by the determination of molecular formulas of the extracted pigments by liquid chromatography coupled with high-resolution mass spectrometry (LCMS-IT-TOF). The influence of plant matrix on gomphrenins’ stability and generation of their derivatives, including the extraction kinetics, was determined by studying the concentration profiles in the primary and diluted infusions. Isolated and purified acylated gomphrenins from the same plant material were used for the preliminary determination of their decarboxylated derivatives. The acylated gomphrenins were found to be more stable than nonacylated ones. Citric acid addition had a degradative influence on natural gomphrenins mainly during the longer tea brewing process (above 15 min); however, the presence of plant matrix significantly increased the stability for betacyanins’ identification.

Study on Alkylation of Catechol with Ethanol by Al-P-Ti-O Oxides

2012 ◽  
Vol 599 ◽  
pp. 114-117 ◽  
Author(s):  
Xiao Mei Zhu ◽  
Bing Sun ◽  
Cheng Huo
Keyword(s):  
Citric Acid ◽  
Surface Area ◽  
Vapour Phase ◽  
Cane Sugar ◽  
Precipitation Method ◽  
Title Reaction ◽  
Catalytic Activities ◽  
P Content ◽  
The Stability ◽  
Ti Content

Vapour-phase alkylation of catechol with ethanol has been investigated over Al-P-Ti-O oxides prepared by non-uniform precipitation method. The catalytic activities decrease with the increase of P content. The catalytic activities increase with increasing Ti content, while the selectivity to guathol decreases. The results of XRD characterization demonstrate that the increase of titanium and the addition of additive affects the structure of the catalysts. The addition of additive (cane sugar or citric acid) decrease the catalytic activities of the catalysts, while increase the stability of the catalyst. Both the conversion of catechol and the selectivity to guathol decrease by the addition of additive, and the C-alkylation products increase obviously. The results indicate that the appropriate pores and surface area are enough for the title reaction, lager pore and higher surface area are favorable to C-alkylation products and stability of catalyst.

scholarly journals Organic/Inorganic Superabsorbent Hydrogels Based on Xylan and Montmorillonite

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Shuang Zhang ◽  
Ying Guan ◽  
Gen-Que Fu ◽  
Bo-Yang Chen ◽  
Feng Peng ◽  
...  
Keyword(s):  
Compressive Modulus ◽  
Cross Linking ◽  
Swelling Properties ◽  
Ph Values ◽  
Swelling Capacity ◽  
Wide Ph Range ◽  
Grafting Copolymerization ◽  
Ph Range ◽  
Influence Of Ph ◽  
Superabsorbent Hydrogels

The unique organic/inorganic superabsorbent hydrogels based on xylan and inorganic clay montmorillonite (MMT) were prepared via grafting copolymerization of acrylic acid (AA) and 2-acrylamido-2-methylpropanesulfonic acid (AMPS) withN,N-methylenebisacrylamide (MBA) as a cross-linking agent and potassium persulfate (KPS) as an initiator. The effect of variables on the swelling capacity of the hydrogels, such as the weight ratios of MMT/xylan, MBA/xylan, and AMPS/AA, was systematically optimized. The results indicated that the superabsorbent hydrogels comprised a porous cross-linking structure of MMT and xylan with side chains that carry carboxylate, carboxamide, and sulfate. The hydrogels exhibit the high compressive modulus (E), about 35–55 KPa, and the compression strength of the hydrogels increased with an increment of the MMT content. The effect of various cationic salt solutions (LiCl, CaCl2, and FeCl3) on the swelling has the following order: Li+> Ca2+> Fe3+. Furthermore, the influence of pH values on swelling behaviors showed that the superabsorbent composites retained around 1000 g g−1over a wide pH range of 6.0–10.0. The xylan-based hydrogels with the high mechanical and swelling properties are promising for the applications in the biomaterials area.

scholarly journals Journal of Food Quality Thermal Degradation of Plum Anthocyanins: Comparison of Kinetics from Simple to Natural Systems

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Mihaela Turturică ◽  
Nicoleta Stănciuc ◽  
Claudia Mureșan ◽  
Gabriela Râpeanu ◽  
Constantin Croitoru
Keyword(s):  
Antioxidant Activity ◽  
Citric Acid ◽  
Thermal Degradation ◽  
Fluorescence Spectra ◽  
Degradation Rate ◽  
Natural Systems ◽  
Degradation Rate Constant ◽  
Higher Temperature ◽  
Lower Temperature ◽  
The Stability

The stability of anthocyanin was assessed over a temperature range of 50–120°C in different simulated plum juices in order to compare the thermal behavior in the presence of certain compounds. The results were correlated with the antioxidant activity and intrinsic fluorescence spectra. The results suggested significant changes, especially at higher temperature; hence, increase in the fluorescence intensity and some bathochromic and hypsochromic shifts were observed. Anthocyanins in natural matrices presented the highest rate for degradation, followed by the anthocyanins in juices with sugars. Values of the activation energies were 42.40 ± 6.87 kJ/mol for the degradation in water, 40.70 ± 4.25 kJ/mol for the juices with citric acid, 23.03 ± 3.53 kJ/mol for the juices containing sugars, 35.99 ± 3.60 kJ/mol for simulated juices with mixture, and 14.19 ± 2.39 kJ/mol for natural juices. A protective effect of sugars was evidenced, whereas in natural matrices, the degradation rate constant showed lower temperature dependence.

Sign in / Sign up

Export Citation Format

Share Document