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1.
J Mater Chem B ; 11(1): 10-32, 2022 12 22.
Article in English | MEDLINE | ID: mdl-36484467

ABSTRACT

The toxicity of metal nanoparticles has introduced promising research in the current scenario since an enormous number of people have been potentially facing this problem in the world. The extensive attention on green nanoparticle synthesis has been focussed on as a vital step in bio-nanotechnology to improve biocompatibility, biodegradability, eco-friendliness, and huge potential utilization in various environmental and clinical assessments. Inherent influence on the study of green nanoparticles plays a key role to synthesize the controlled and surface-influenced molecule by altering the physical, chemical, and biological assets with the provision of various precursors, templating/co-templating agents, and supporting solvents. However, in this article, the dominant characteristics of several kinds of lipopeptide biosurfactants are discussed to execute a critical study of factors affecting synthesis procedure and applications. The recent approaches of metal, metal oxide, and composite nanomaterial synthesis have been deliberated as well as the elucidation of the reaction mechanism. Furthermore, this approach shows remarkable boosts in the production of nanoparticles with the very less employed harsh and hazardous processes as compared to chemical or physical method-based nanoparticle synthesis. This study also shows that the advances in strain selection for green nanoparticle production could be a worthwhile and strong economical approach in futuristic medical science research.


Subject(s)
Environmental Science , Metal Nanoparticles , Humans , Green Chemistry Technology/methods , Metal Nanoparticles/toxicity , Metal Nanoparticles/chemistry , Metals , Oxides
2.
Molecules ; 25(24)2020 Dec 17.
Article in English | MEDLINE | ID: mdl-33348597

ABSTRACT

Epoxy resins (EP) have been used as a thermos-setting material in the field of coating, casting, bonding agent, and laminating. However, a major drawback associated with its use is the lack of good flaming properties, and it is responsible for heavy smoke along with hazardous gases considerably limiting its uses in various fields. In this study, N-ethanolamine triazine-piperizine, a melamine polymer (ETPMP), was established as a new charring-foaming agent and was successfully synthesized with ethanolamine, piperizine, cyanuric chloride, and melamine as precursor molecules via the nucleophilic substitution reaction method. Elemental analysis and Fourier transform infrared (FTIR) spectroscopy analysis were applied to approve the synthesis of ETPMP and confirmation of its structure and characterization. The epoxy coating of intumescent flame retardant (IFR) was equipped by introducing ETPMP, ammonium polyphosphate (APP), and copper oxide (CuO) in multiple composition ratios. CuO was loaded at various amounts into the IFR-coating system as a synergistic agent. The synergistic action of CuO on IFR coatings was scientifically examined by using different analytical tests such as vertical burning test (UL-94V), limited oxygen index (LOI), thermal gravimetric analysis (TGA), cone calorimeter, and scanning electron microscope (SEM). The results showed that small changes in the amount of CuO expressively amplified the LOI results and enhanced the V-0 ratings in the UL-94V test. The TGA data clearly demonstrate that the inclusion of CuO can transform the thermal deprivation behavior of coatings with a growing char slag proportion with elevated temperatures. Information from cone calorimeter data affirmed that CuO can decrease the burning factors by total heat release (THR) together with peak heat release rate (PHRR). The SEM images indicated that CuO can enrich the power and compression of the intumescent char that restricts the movement of heat and oxygen. Our results demonstrate a positive influence of CuO on the epoxy-headed intumescent flame retardant coatings.


Subject(s)
Copper/chemistry , Epoxy Resins/chemistry , Flame Retardants/chemical synthesis , Piperazines/chemical synthesis , Polymers/chemistry , Benzhydryl Compounds/chemistry , Calorimetry , Differential Thermal Analysis , Phenols/chemistry , Piperazines/chemistry , Spectroscopy, Fourier Transform Infrared , Triazines/chemistry
3.
Polymers (Basel) ; 12(11)2020 Nov 17.
Article in English | MEDLINE | ID: mdl-33212915

ABSTRACT

Ethylenediamine modified Ammonium polyphosphate (EDA-MAPP), and Charring-Foaming Agents (CFA) was prepared via a simple chemical approach and further utilizes for the preparation of Epoxy resin based intumescent flame retardation coatings. The ratio belongs to MAPP and CFA was fixed at 2:1 ratio. Comparative thermo gravimetric analysis TGA study of Modified Ammonium polyphosphate (MAPP) and Ammonium polyphosphate (APP) investigated. Sb2O3 was introduced into flame retardation coating formulation at various amounts to evaluate the synergistic action of Sb2O3 along with flame retardant coating system. The synergistic action of Sb2O3 on flame retardation coating formulation was studied by vertical burning test (UL-94V), thermo gravimetric analysis (TGA), Limited Oxygen Index (LOI), and Fourier Transform Infra-Red spectroscopy (FTIR). The UL-94V results indicated that adding Sb2O3 effectively increased flame retardancy and meets V-0 ratings at each concentration. The TGA results revealed that the amalgamation of Sb2O3 at each concentration effectively increased the thermal stability of the flame retardant coating system. Cone-calorimeter study results that Sb2O3 successfully minimized the combustion parameters like, Peak Heat Release Rate (PHRR), and Total Heat Release (THR). The FTIR result shows that Sb2O3 can react with MAPP and generates the dense-charred layer which prevents the transfer of heat and oxygen.

4.
J Environ Sci (China) ; 31: 104-23, 2015 May 01.
Article in English | MEDLINE | ID: mdl-25968265

ABSTRACT

The direct determination of toxic metal ions, in environmental samples, is difficult because of the latter's presence in trace concentration in association with complex matrices, thereby leading to insufficient sensitivity and selectivity of the methods used. The simultaneous removal of the matrix and preconcentration of the metal ions, through solid phase extraction, serves as the promising solution. The mechanism involved in solid phase extraction (SPE) depends on the nature of the sorbent and analyte. Thus, SPE is carried out by means of adsorption, ion exchange, chelation, ion pair formation, and so forth. As polymeric supports, the commercially available Amberlite resins have been found very promising for designing chelating matrices due to its good physical and chemical properties such as porosity, high surface area, durability and purity. This review presents an overview of the various works done on the modification of Amberlite XAD resins with the objective of making it an efficient sorbent. The methods of modifications which are generally based on simple impregnation, sorption as chelates and chemical bonding have been discussed. The reported results, including the preconcentration limit, the detection limit, sorption capacity, preconcentration factors etc., have been reproduced.


Subject(s)
Metals/chemistry , Polystyrenes/chemistry , Polyvinyls/chemistry , Water Pollutants, Chemical/chemistry , Adsorption , Polymers/chemistry
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