Figure 2 - uploaded by Hidayet Mazi
Content may be subject to copyright.
Comparison of FT-IR spectra of maleic anhydride, decanol and the modified products MD-75 and MD-100.
Source publication
Maleic anhydride was modified with 1-decanol at two different ratios to obtain derivatives named MD-75 (75% modified) and MD-100 (100% modified). By using these derivatives and acrylamide (AAm), many hydrogels with different AAm/MD ratios were synthesized. Ammonium persulphate (APS), N,N,N′,N′-tetramethyl ethylenediamine (TMEDA) and N,N′-methylene...
Contexts in source publication
Context 1
... this study, FT-IR was used to elucidate the mechanism of the modification reaction. FT-IR spectra of maleic anhydride, decanol and the modified product were recorded and represented in Figure 2 for comparison. It can be seen from Figure 2 that weak C-H stretching at 3070 cm -1 , strong and broad symmetric C=O stretching at 1780 cm -1 and weak but sharp asymmetric C=O stretching bands at 1850 cm -1 are evident in MA. 40 The most prominent bands in decanol are OH stretching band between 3150 and 3450 cm -1 and C-H stretching bands at 2850 and 2920 cm -1 . ...
Context 2
... spectra of maleic anhydride, decanol and the modified product were recorded and represented in Figure 2 for comparison. It can be seen from Figure 2 that weak C-H stretching at 3070 cm -1 , strong and broad symmetric C=O stretching at 1780 cm -1 and weak but sharp asymmetric C=O stretching bands at 1850 cm -1 are evident in MA. 40 The most prominent bands in decanol are OH stretching band between 3150 and 3450 cm -1 and C-H stretching bands at 2850 and 2920 cm -1 . The observation of the OH stretching band in the MD-75 spectrum and being wider than decanol indicates the presence of the COOH group. ...
Similar publications
In this study, the effects of ultrasonic (US), ozone (O3), or ozone-ultrasonic (O3-US) pretreatments on the structural and functional properties of soluble dietary fibers (SDFs) obtained from lemon peel were investigated. Scanning electron microscopy observation showed that, US-SDF, O3-SDF, and O3-US-SDF showed more looser surface and porous charac...
Pharmaceutical tablet disintegration is a critical process for dissolving and enabling the absorption of the drug substance into the blood stream. The tablet disintegration process consists of multiple connected and interdependent mechanisms: liquid penetration, swelling, dissolution, and break-up. One key dependence is the dynamic change of the po...
Childhood malnutrition is one of the most persistent public health problems throughout developing countries including Nigeria. This study focused on the evaluation of complementary food produced by solid-state fermentation of Fonio and Soybean using Rhizopus oligosporus (2710) and Orange-fleshed sweet potatoes (OFSP) using Lactobacillus planterum,...
The freeze-thaw (F/T) method is commonly employed during the processing and handling of drug substances to enhance their chemical and physical stability and obtain pharmaceutical applications such as hydrogels, emulsions, and nanosystems (e.g., supramolecular complexes of cyclodextrins and liposomes). Using F/T in manufacturing hydrogels successful...
To improve the rough texture and hypoglycemic ability of sea buckthorn insoluble dietary fiber (IDF), a novel combined modification method was developed in this study. The IDF was treated with ball milling and cellulase treatment to obtain co-modified insoluble dietary fiber (CIDF). The physicochemical and functional properties of IDF, milled insol...
Citations
... BIS AQ solution (4% w/v) was added to each pectin and 2HEMA mixture. The following substances were added to the test tube at 60 • C: 10% w/v pluronic F127/poloxamer 407, 2% v/v TEMED, and 1% w/v APS AQ solution [23]. For efficient mixing, the polymerization process was operated for 10 min, and as substances were added to the test tube the reaction caused intensive shaking ( Figure S2) [24]. ...
Super-porous hydrogels are considered a potential drug delivery network for the sedation of gastric mechanisms with retention windows in the abdomen and upper part of the gastrointestinal tract (GIT). In this study, a novel pH-responsive super-porous hybrid hydrogels (SPHHs) was synthesized from pectin, poly 2-hydroxyethyl methacrylate (2HEMA), and N, N methylene-bis-acrylamide (BIS) via the gas-blowing technique, and then loaded with a selected drug (amoxicillin trihydrate, AT) at pH 5 via an aqueous loading method. The drug-loaded SPHHs-AT carrier demonstrated outstanding (in vitro) gastroretentive drug delivery capability. The study attributed excellent swelling and delayed drug release to acidic conditions at pH 1.2. Moreover, in vitro controlled-release drug delivery systems at different pH values, namely, 1.2 (97.99%) and 7.4 (88%), were studied. These exceptional features of SPHHs—improved elasticity, pH responsivity, and high swelling performance—should be investigated for broader drug delivery applications in the future.
Superabsorbents (SAs) are magic materials that became a point of interest in the research community over a long period. Several studies related to these materials are conducted to manufacture diverse types of superabsorbents to meet the needs of the industrial sector. Superabsorbents are materials capable of absorbing water or fluids about 1000 times in comparison to their weight in dry form and release them in a consistent and slow manner. Due to this property of huge water/fluids absorption, these materials have great applications in the production of hygiene products and the medical field. In 2019, only in the hygiene market, SAs contributes about USD 9.58 billion. SAs are synthetic and generate huge environmental issues; as a consequence of this, bio-based SAs draw the attention of the research community due to their biodegradable, renewable, and biocompatible nature. This chapter focuses on the classification, methods of synthesis, and characterization of SAs. It also provides an overview of their applications in different fields including agriculture, wastewater treatment, agriculture, biomedical, and hygiene. This Chapter also performed an analysis of research trends in SAs during the last decade (2011–2021) to visualize major research progress in this field. The task is served by title analysis, abstract analysis, keyword analysis, and publication year’s analysis in the number of publications on SAs.KeywordsSuperabsorbentsWater absorptionHygiene marketMedical fieldWastewater treatmentSwellingBio-based
Superabsorbent polymers are 3-dimensional hydrophilic polymeric materials with the capacity to hold large amounts of fluids i.e. can be 1000 times their original mass by maintaining their dimensional stability. These water-absorbing hydrogels when mixed with an aqueous solution absorb and retain fluids by forming hydrogen bonds with the water molecules. The absorbance and swelling capacity can be modified by changing the concentration of crosslinking polymers. To meet the desirable property for various applications, a considerable number of studies are conducted to develop some polymers with special chemical properties termed “Smart superabsorbents”. These are the class of advanced polymers with the ability to change their physical properties in response to environmental stimuli such as a change in Temperature, Pressure, pH, Light, etc. Smart superabsorbent hydrogels have tremendous applications in bio-medical, water purification, forming actuators, and conductive hydrogels due to their fast macroscopic changes in structure and reversible transition properties. These are synthetic polymers derived from petroleum products such as acrylates and acrylamides with high production costs and toxicity. To minimize the toxicity researchers are moving their interest towards bio-friendly hydrogels derived from living organisms or chemically produced from biological materials. There are different polysaccharides-based SAPs such as alginate, cellulose, chitosan, etc. used to form hydrogels, which pose less water absorption capacity and poor life span in comparison with the synthetic one. So the focus is shifted towards making semi-synthetic SAP to target the interest of specialized applications where external stimuli are used to create fine-tuned SAP properties. This chapter covers approaches adopted from the literature to study semi-synthetic smart superabsorbents with minimal toxicity.KeywordsSmart superabsorbentsHydrogelSwellabilityToxicityBio-based superabsorbents
Novel thermal/pH‐sensitive quaternary chitosan‐based semi‐interpenetrating network hydrogels were facilely fabricated via an amino‐anhydride click reaction in aqueous solutions and used for water treatment. First, a series of terpolymers (PNAM) of acrylamide, N‐isopropylacrylamide, and maleic anhydride was prepared via free radical copolymerization. Next, PNAM, poly(allylaminehydrochloride), and quaternary chitosan were dissolved in water, rapid gelation was observed after the pH of the solution was adjusted to alkaline. Then, single‐factor experiments were applied to optimize the preparation parameters. The hydrogel was found to be thermal/pH sensitive. Finally, choosing Eosin Y as a model dye, the effect of the initial concentration, temperature, contact time, adsorbent dosage, ionic strength, and pH on the adsorption behavior was studied. The adsorption capacity could reach 1799 mg/g under optimized conditions. The adsorption performance of the hydrogels can be well described by the pseudo‐second‐order kinetic model and the Langmuir model. The thermodynamic study suggests that the adsorption of Eosin Y is a spontaneous, endothermic, and entropy‐increasing process. In view of its adsorption performance and facile preparation process, the hydrogel is expected to be used as a promising adsorbent. The preparation and application of thermal/pH‐sensitive semi‐IPN hydrogels.
The applications of hydrogels in industry and academia are numerous and well known. However, the use of these cross-linked polymer materials is presented in this article with a particular purpose that is unexplored in the literature: to reduce water content from diesel aiming at meeting commercial specifications for turbidity in a continuous process. Currently, there are different processes in the industry to reduce water content in fuels, such as coalescing filters (for non-soluble water) and distillation (with high energy demand). However, this work showed the potential application of hydrogel as an alternative technology, being able to remove soluble water with ease of installation and low energy consumption. Sodium polyacrylate (SPA) hydrogel was chosen among others - polyacrylamide (PAAm) and poly(acrylic acid) (PAA) hydrogels - to treat cloudy diesel in a fixed bed. This polymer was characterized in terms of morphology and chemical composition and the swelling degree kinetics was studied considering different lyophilisation conditions and particle diameters. Also, the effect of type of external media and temperature on the equilibrium swelling degree were assessed. The lyophilized SPA hydrogel reduced the water content of diesel from around 630 ppm to near 100 ppm and the turbidity from Haze 6 down to Haze 1. These results demonstrate that the new technology has a potential use in petroleum refineries, storage and distribution facilities and also in small scale applications, such as in gas stations.
A superabsorbent resin (SAR) is a functional polymer with a high water absorption capacity, which has been widely used in many fields. In this study, a modified aqueous solution polymerization process was adopted to synthesize a SAR. The optimum synthetical mass ratios of starch, bentonite, potassium persulfate (K2S2O8), and N,N′-methylene-bis-acrylamide to acrylic acid (AA) were 7.14%, 3.57%, 0.29%, and 0.057%, respectively, and the neutralization degree of AA was 50%. The molecular structure and the surface morphologies of the SAR were confirmed using Fourier transform infrared spectroscopy and scanning electron microscopy. The SAR had a water absorbency of 1300 mL/g in distilled water and 56 mL/g in 0.9 wt.% NaCl solution. The water absorption rate reached 72.65% of the maximum water absorption in 1 hour and swelled to equilibrium in 4 hours. The water retention rate was 45.86% after heating and evaporation at 150°C for 1 hour. The moisture absorption rate reached 28.2% after 10 days of placement. The modified technology provides a new synthetic method for production of SARs, which is characterized by a lack of nitrogen protection, the direct use of raw AA and potato starch, a simplified synthesis process, substantially improved efficiency, and lower production costs.
Clean and safe water resources play a key role in environmental safety and human health. Recently, hydrogels have attracted extensive attention due to their non-toxicity, controllable performance, and high adsorption. Herein, a semi- interpenetrating network hydrogel (semi-IPN-Gel) adsorbent based on quaternary cellulose (QC) was prepared by the amino-anhydride click reaction between maleic anhydride copolymer and polyacrylamine hydrochloride (PAH), and its adsorption properties for Eosin Y were studied. First, a binary copolymer (PAM) of acrylamide and maleic anhydride was synthesized by free radical polymerization. Then, the PAM, QC and PAH were dissolved in water, and the pH of the solution was adjusted to alkaline. Semi-IPN-Gel was successfully prepared by fast anhydride-amino click reaction. The preparation conditions of hydrogels were optimized by single-factor experiments. Finally, taking Eosin Y as a model pollutant, the adsorption performance of Eosin Y was studied. The factors influencing the adsorption capacity of the absorbents such as initial concentration of the Eosin Y, temperature, the amount of absorbent, ionic strength and pH of the Eosin Y solutions were investigated. And adsorption data were analyzed via the kinetic model and the isothermal model, indicating that the adsorption process of the hydrogel is a single layer chemisorption process.
