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The inhibition zones of the samples against (a) E. coli bacteria, (b) S. aureus bacteria
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HBPE of different generations were synthesized using 4-hydroxybenzoic acid and 2,2′,2″-nitrilotriethanol via the A2 + B3 method. The reaction was carried out in a dry nitrogen atmosphere using p-toluene sulfonic acid (p-TSA) as an acid catalyst. The chosen molar ratios of 2,2′,2″-nitrilotriethanol to 4-hydroxybenzoic acid were 1:3, 1:6, and 1:21 fo...
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Isothiazolinones methylisothiazolinone (MI) and methylchloroisothiazolinone (MCI), and parabens methylparaben (MP), ethylparaben (EP), propylparaben (PP) and butylparaben (BP) are the most common synthetic preservatives. They are all known to be potential skin allergens that lead to contact dermatitis. Thus, the identification of these unsafe chemi...
Citations
... The coating nanoparticles on textile materials such as cotton fiber, polyurethane foam, and polyester can provide antibacterial properties [3,4]. The antibacterial material can be developed using silver nanoparticles coated onto textile materials [6][7][8][9]. The antibacterial activity of nylon, polyester, cotton-coated nanoparticles is strongly influenced by the size, shape, chemical properties, and the surface roughness [5]. ...
... The cotton cloth coated with silver nanoparticles shows anti-bacterial activity against Escherichia coli and Staphylococcus aureus. Textiles coated silver nanoparticle shows antibacterial activity against Escherichia coli and S. aureus [1,3,[4][5][6][8][9], Pseudomonas aeruginosa, Enterobacter aerogenes, Proteus mirabilis, K. pneumoniae, Candida albicans yeasts, and micromycetes [32]. Presumably, under the impregnation of cotton with metal ions and ironing at 200 °C, the basis of cotton, cellulose, simultaneously reduces of ions and stabilizes the appearing nanoparticles [32]. ...
In this work, cotton fiber was fabricated using silver nanoparticles to produce hydrophobic and antibacterial material. The silver nanoparticle was prepared with chemical reduction method using trisodium citrate as reducing agent and PVA as stabilizer. Silver nanoparticle was deposited on cotton fibers as antibacterial agent and HDTMS 4% v/v was coated on those as hydrophobic agent. The cotton fibers before and after modification were characterized its functional groups, contact angles, and antibacterials activities. The functional groups of cottons were determined by using ATR-FTIR, hydrophobic properties of cottons were determined by measuring contact angle, and antibacterial activities of cottons were determined by measuring clear zone. The addition of HDTMS decreased the intensity of absorption bands of functional groups but increased contact angle of cotton cloth. The cotton cloth-silver nanoparticle shows the highest antibacterial properties. The antibacterial activity of cotton cloth without and with modification against Staphylococcus aureus ATCC 25923 and Eschericia coli 32518 were significantly different.
... The development of coatings with antimicrobial properties has led to great commercial demand. Inorganic nanoparticles with antimicrobial activity are emerging as a new class of additives to coating materials to fulfill the increasing general demands for hygiene in daily life [89]. Metallic silver and silver based compounds have been investigated by several researchers as an antibacterial and antifungal agent over several decades. ...
Epoxy resin GY250 representing diglycidyl ethers of bisphenol-A (DGEBA) was reinforced with 1, 3 and 5wt % of surface functionalized silver nanoparticles (F-AgNPs) which were synthesized using Couroupita guianensis leaves extract with a view of augmenting the corrosion control property of the epoxy resin and also imparting antimicrobial activity to epoxy coatings on mild steel. Corrosion resistance of the coatings was evaluated by EIS, potentiodynamic polarization studies and cross scratch tests. AFM, SEM, HRTEM and EDX were utilized to investigate the surface topography, morphology and elemental composition of the coatings on MS specimens. Results showed that the corrosion resistance, hardness and Tg of the DGEBA/F-AgNPs coatings increased at 1wt % of F- AgNPs. The DGEBA/F-AgNPs coatings also offered manifold antimicrobial protection to the MS surfaces by inhibiting the growth of biofilm forming bacteria like P. aeruginosa, B. subtilis, the most common human pathogen E. coli and the most virulent human pathogenic yeast C. albicans.
... The plates were examined for possible clear zone formation after overnight incubation at 37 • C. The presence of clear zone around the steel samples on the plates was recorded as an inhibition against the test microbial species. The entire experiments were conducted in a laminar hood to prevent any contamination [38]. ...
Herein we report the synthesis of ibuprofen-based hyperbranched polyester ranging from morphological, thermal and fluorescent behaviour. The proposed synthesis of ibuprofen-based hyperbranched polyester was achieved by a simple acid chloride approach. The formation of aromatic ester linkage in the product was confirmed using Fourier transform infrared and nuclear magnetic resonance spectroscopy. The morphology of ibuprofen-based hyperbranched polyester was investigated by using the X-ray diffraction, scanning electron microscopy and differential scanning calorimetry (DSC) analyses. The glass transition temperature (~78°C) and double melting peaks of ibuprofen-based hyperbranched polyester were observed using DSC. The liquid chromatography-mass spectrometry analysis confirmed the chemical structure and the molecular weight of the ibuprofen-based hyperbranched polyester. The presence of broad absorption peak at 301 nm in UV region indicated the fluorescent property of ibuprofen-based hyperbranched polyester. The antimicrobial tests of ibuprofen-based hyperbranched polyester were carried against Gram-negative organisms such as Escherichia coli MCIM 2065 and Salmonella paratyphi MCIM 2501, Gram-positive organisms such as Bacillus subtilis NCIM 2063 and Staphylococcus aureus NCIM 2079 and fungi such as Aspergillus niger MTCC 1344 and Candida albicans MTCC 3100. The result of agar disc diffusion method showed that the polymer had higher antimicrobial potential towards fungi than bacteria.
A series of new nickel complexes based on hyperbranched salicylaldimine ligands have been prepared in good yields and characterized by FT-IR, ¹H NMR, UV, ESI-MS and TGA. Upon activation with methylaluminoxane (MAO) or diethylaluminum chloride (DEAC), these new precatalysts showed high activity in ethylene oligomerization, and notably remarkably high selectivity of high carbon olefins in the presence of DEAC. The catalytic performance was substantially affected by the solvent type, reaction conditions and the structure of catalyst. Under optimized conditions, precatalyst C1 led to TOF = 13.65 × 10⁵ g/mol Ni·h and 21.53% selectivity for high carbon olefins. The result of thermal analysis revealed that the complex C1 was stable up to 298.4 °C. The research result of the kinetics of ethylene oligomerization found that the pressure drop of ethylene consumption sharply increased in the initial stage, however with the prolonged reaction time, the pressure drop of ethylene consumption varied a little.
A waterborne polymer is a greener alternative than a solvent borne one because of its nontoxicity and nonflammability nature as well as it does not need any organic solvent. Thus, three biodegradable waterborne hyperbranched aliphatic polyesters were synthesized from citric acid, poly(ethylene glycol), glycerol and 2,2-bis(hydroxyl methyl) propionic acid, by a polycondensation reaction without using any additional catalyst or neutralizing agent. The structures of these polyesters were elucidated from spectroscopic analyses. Degrees of branching of the polymers were evaluated from C-13 NMR spectra and found to vary from 0.59 to 0.70. Thermoset of these polyesters was obtained by curing of a formulation composed of waterborne hyperbranched polyester (57.1%), hyperbranched epoxy (28.87%) and poly(amidoamine) (14.28%) using water as a solvent with a little amount of THF as a cosolvent. The performance characteristics such as tensile strength (4.0-7.8 MPa), elongation at break (175-245%), toughness (655-1742 MPa), impact resistance (>1 m), gloss (89-96), scratch resistance (3-4 kg) and chemical resistance (good) of the thermosets were evaluated. The results clearly revealed the profound influence of citric acid content on performance of such polyester thermosets. These polyester thermosets were found to be highly biodegradable by Pseudomonas aeruginosa and Bacillus subtilis bacterial strains and also exhibited hemocompatibilty. Therefore, the citric acid based sustainable tough hyperbranched polyester thermosets with acceptable performance were obtained through a facile and environmentally benign route.
