This study presents an outline of the 12 principles of green relevance in nanomaterial synthesis. The goal of using green renewable resources is to protect the environment from negative effects, ...which can be achieved
several main directions, including the choice of innocuous solvents, such as supercritical (SC) fluids or water, and/or additives (
stabilizers, capping, and reducing agents) such as polysaccharides, using alternative reaction circumstances, and the development of energy-efficient synthetic methods. This review shows how different green renewable resources routes are reducing the impact of chemical processes on the environment and how their benefit can be achieved in nanotechnology applications such as green energy.
The aim of this study was to increase both the rates of dissolution and bioavailability of the amlodipine (Amlo) drug. Due to the low cost, high solubility, and amorphous state, polyvinylpyrrolidone ...(PVP) has been used as a drug carrier in the solid dispersion process. Through applying an irradiation technique, powder of (PVP) is irradiated with six 0–50 kGy irradiation doses. The six irradiated (PVP) samples were characterized using gel permeation chromatography, electron spin resonance, and Fourier transform infrared (FT-IR) spectroscopy. The formulation of six (PVP/Amlo) samples at a ratio of 2:1 wt/wt were characterized using FT-IR spectroscopy and X-ray powder diffraction. In vitro dissolution of (Amlo) drug was assessed in a water solvent at pH 1.2 and pH 7. Results demonstrated that there is a change in the physicochemical properties of irradiated (PVP). FT-IR confirmed that there is an intermolecular H bond between the (Amlo) drug and (PVP) polymer. XRD confirmed that (PVP) changes the crystalline (Amlo) to amorphous amlodipine. Irradiated (PVP) at a dose of 20 kGy released approximately 89% from 40 mg of (Amlo) in 60 s. The in vitro rate of amlodipine dissolution depends on the drug–polymer intermolecular H bond. The rate of (Amlo) dissolution is increased due to the drug–drug intramolecular hydrogen bonding replaced with the drug–polymer intermolecular hydrogen bonding, which reduces the crystal packing. Irradiated (PVP) improved the rate of (Amlo) dissolution compared to unirradiated (PVP).
•Starch-based three hydrogels were prepared by gamma-radiation technique.•The swelling degree of the IPN hydrogels decreases with increased starch content.•The IPN hydrogels were evaluated as soil ...conditioner in heavy metals and alkaline soil pH > 9.
This article highlights the advance of the radiation synthesis of starch-based hydrogel to be used as a soil conditioner. The hydrogels samples have been prepared in weight ratios 1:3, 2:2 and 3:1 (wt:wt) for starch (St), polyvinylpyrrolidone (PVP) and acrylamide (Am), individually. At dose of 30 kGy, the polymerization reaction is occurred to produce IPN hydrogels using gamma irradiation technique. The impact of starch content on the behavior of swelling and water absorption from moisture soil for the (PAAm/PVP), (PAAm/St) and (PVP/St) INP hydrogels was investigated. The chemical composition and morphology of the (PVP/PAAm), (PAAm/St) and (PVP/St) IPN is described using Fourier Transform Infrared Spectroscopy (FTIR) and the Scanning Electron Microscope (SEM). X-ray diffraction (XRD) confirm the effect of starch on the crystanillity of (PAAm/St) and (PVP/St) INP hydrogels. The result indicated that, the degree of swelling of the IPN hydrogels decreases with increased starch content. This is attributing to the existence of intra- and inter-molecular H bonds in the IPN hydrogels are increased with increased starch content as performed by FT-IR. Three soil conditioners of ratio PVP/St, PAAm/St and PVP/PAAm INP hydrogels (3/1) were chosen to determine the effectiveness of heavy metals and alkaline soil pH > 9 for sunflower plating (Helianthusannuus). The treatments were irrigated weekly, the obtained result showed that the effectiveness of soil conditioner is in this order: PVP/PAAm > control > PVP/St > PAAm/St.
This review’s objectives are to provide an overview of the various kinds of biopolymer hydrogels that are currently used for bone tissue and periodontal tissue regeneration, to list the advantages ...and disadvantages of using them, to assess how well they might be used for nanoscale fabrication and biofunctionalization, and to describe their production processes and processes for functionalization with active biomolecules. They are applied in conjunction with other materials (such as microparticles (MPs) and nanoparticles (NPs)) and other novel techniques to replicate physiological bone generation more faithfully. Enhancing the biocompatibility of hydrogels created from blends of natural and synthetic biopolymers can result in the creation of the best scaffold match to the extracellular matrix (ECM) for bone and periodontal tissue regeneration. Additionally, adding various nanoparticles can increase the scaffold hydrogel stability and provide a number of biological effects. In this review, the research study of polysaccharide hydrogel as a scaffold will be critical in creating valuable materials for effective bone tissue regeneration, with a future impact predicted in repairing bone defects.
Different nanostructure shapes of polyaniline (PAni) particles such as rod and spherical shapes were prepared using gamma radiation. Gamma radiation is advantageous over other conventional methods ...because it provides a pure nanoparticle without by-products or any additives. The four solutions of aniline monomer Ani were dissolved in aprotic polar solvent
N
,
N
-dimethyl formamide (DMF) in different pH values and exposed to gamma radiation at a dosage of 50 kGy. The pH effect in terms of size and structure of PAni was investigated with four values 1, 5, 8 and 13 adjusted by adding HCl. A common polymerization mechanism induced by radiation is proposed as a radical cation polymerization, which is an environment friendly and cost effective mechanism without any side products or contaminants. The size and size distribution of PAni NPs suspension in DMF solvent were investigated by TEM and DLS. The results clearly showed that the ionizing radiation is an effective tool to produce a shape-controllable size. The changes of the spectrum with the pH of the polymerization solution obtained from UV–visible spectroscopy revealed that the smallest particles of PAni NPs can easily be obtained at low pH. The PAni particles are obtained with two morphologies (such as rod and spherical shapes).
A copolymer hydrogel consisting of Polyacrylic Acid (PAAc) combined with an irradiated solution of carboxymethyl cellulose (CMC, 1 wt%) was prepared. The focus was on controlling the radiation ...degradation of CMC by exposing it to different six doses of γ‐irradiation from 0 up to 3 kGy. After the irradiation process, the six CMC solution samples were mixed with 10 vol% of Acrylic Acid (AAc) monomer and re‐irradiated at a dose of 25 kGy to begin the polymerization process. A scanning electron microscope (SEM) was used to image the macroporous structure of the obtained (CMC/PAAc) hydrogel. Moreover, the SEM image confirmed the interpenetrating and semi‐interpenetrating polymer network structure based on the irradiation process. The controlled release of urea is achieved due to the binding between urea and the functional groups of the investigated hydrogel by hydrogen bonds. The growth of common bean plant (Phaseolus vulgaris L.) and chlorophyll contents were increased when soils were treated with (CMC/PAAc) compared with soils with free hydrogel in water‐stress conditions.
In response to the pandemic of COVID-19, various unexpected environmental impacts in many countries have been rising. Millions of gloves and masks are used and thrown away daily around the globe. ...Incorrect disposal of COVID-19 waste without disinfection preparation could expose people and healthcare personnel to the possibility of spreading the infection of coronaviruses. This article finds an appropriate way to disinfect the waste of coronavirus-infected items by involving various physical factors, chemical and biological or physiological factors. Policymakers must immediately adopt disinfection technology to achieve green recovery of covid-19 waste that encourages development and sustains climate change. Regarding previously published papers and research results, this article intends to investigate the plastic pollution research status before and during the COVID-19 pandemic and outline safely disinfecting COVID-19 plastic waste.
Pyrimidinethione nucleosides are effective compounds and have significant and pivotal effects in several fields. New synthetic strategies for many pyrimidinethione nucleosides including acyclic and ...cyclic derivatives have been reported.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
A superabsorbent hydrogel (SAH) composite from starch and polyacrylic acid p(St/AAc) was prepared by free radical polymerization in the presence of potassium persulfate initiator. The effects of two ...polymer composition on gel fraction, swelling, and water retention have been investigated. It was found that swelling was extremely sensitive to the acrylic acid contents; it increased with the decrease of acrylic acid content. Moreover, the hydrogel samples showed an excellent water retention capability. The swelling kinetics and water diffusion mechanism in distilled water were also discussed in order to choose appropriate SAH functioning as soil conditioner of sunflower under drought stress. A pot experiment was carried out to study the ameliorative role of SAH application on sunflower (
Helianthus annuus
L. Var Sakha) plants grown under drought stress. Growth parameters, content of photosynthetic pigments, total proline and phenol, and antioxidant enzymes were determined. The shoot and root length increased up to 49.84% and 5.35% rather than in the absence of SAH. Growth parameters and photosynthetic pigments of sunflower plants grown under drought in the absence of SAH were reduced. Hydrogel application enriched the photosynthetic pigment. Besides, it also decreased the harmful impacts of drought on sunflower plants. The results herein demonstrated that the hydrogel decreased the proline, total phenols, catalase, peroxidase, and polyphenol oxidase content. The findings of this study indicate that the use of hydrogel can be considered as an unconventional and novel tool in the mitigation of drought stress.
Since the corrosion protection of mild steel samples in corrosive media (1 M of hydrochloric acid HCl) was cheap and successful, the ethanol extract of
leaves based on polyvinylpyrrolidone (
/PVP) ...was analyzed using the weight reduction, the open circuit potential, and the potentiodynamic polarization methods. The obtained results explained that the productivity of hindrance increments had the greatest restraint efficiency of ∼81% at 1,000 ppm, as the concentration of the extract increased. Liable for adsorption as a thin layer on the surface of mild steel to protect it, the creation of kaolin-traced phenolic and polysaccharide compounds was confirmed by the Fourier transform infrared spectroscopy analysis. A scanning electron microscope was used to evaluate the inhibitive action of
/PVP against steel in corrosive media and the change in surface morphology was considered. It is presumed that the ethanol removed from the
leaves can fill in as a compelling consumption inhibitor for gentle steel in HCL solution (1 M).
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