Green Synthesis of Antibacterial Cotton Nanocomposites with In Situ Generation of Copper Nanoparticles Using Senna auriculata Leaf Extract as Reductant

2020 ◽  
Vol 12 (5) ◽  
pp. 672-679
Author(s):  
Akepogu Prasad ◽  
Mallavarapu Umamahesh ◽  
Gopiredddy Venkata Subba Reddy ◽  
Seetha Jaswanth ◽  
Gollapudi Venkata Ramanamurthy ◽  
...  

Copper nanoparticles (CuNPs) were bio synthesized instantaneously in nanocomposite cotton fabrics (NCFs), utilizing aqueous Senna auriculata (SA) plant leaves solution as reductant. These NCFs with in situ generation of CuNPs were analyzed with different spectrophotometers such as Scanning Electron Microscope (SEM) combined with electron dispersive X-ray (EDX), Fourier transform infrared (FTIR), Thermogravimetric and Derivative thermogravimetric analysis (TGA and DTA), X-ray diffractometer (XRD) and Differential scanning calorimeter (DSC). The formed CuNPs were tested for their antibacterial and mechanical properties. The SEM results revealed that the bio synthesized CuNPs were spherical in shape and most of them with a mean size of 100 nm. The XRD studies explained the crystalline nature of CuNPs. These NCFs exhibited high thermal stability, good induced mechanical properties and acted as pathogenic killing agent against Gram positive and Gram negative bacteria. The Young's modulus value was found to be 65.81 MPa. The enhanced properties and immediate generation of CuNPs in NCFs can be utilized in medical applications such as antibacterial beds in hospitals, napkins and to make packing materials.

2020 ◽  
Vol 22 (1) ◽  
pp. 105
Author(s):  
Wanting Li ◽  
Zixuan Huang ◽  
Rui Cai ◽  
Wan Yang ◽  
Huawei He ◽  
...  

Silver-based hybrid nanomaterials are receiving increasing attention as potential alternatives for traditional antimicrobial agents. Here, we proposed a simple and eco-friendly strategy to efficiently assemble zinc oxide nanoparticles (ZnO) and silver nanoparticles (AgNPs) on sericin-agarose composite film to impart superior antimicrobial activity. Based on a layer-by-layer self-assembly strategy, AgNPs and ZnO were immobilized on sericin-agarose films using the adhesion property of polydopamine. Scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray powder diffraction spectroscopy were used to show the morphology of AgNPs and ZnO on the surface of the composite film and analyze the composition and structure of AgNPs and ZnO, respectively. Water contact angle, swelling ratio, and mechanical property were determined to characterize the hydrophilicity, water absorption ability, and mechanical properties of the composite films. In addition, the antibacterial activity of the composite film was evaluated against Gram-positive and Gram-negative bacteria. The results showed that the composite film not only has desirable hydrophilicity, high water absorption ability, and favorable mechanical properties but also exhibits excellent antimicrobial activity against both Gram-positive and Gram-negative bacteria. It has shown great potential as a novel antimicrobial biomaterial for wound dressing, artificial skin, and tissue engineering.


2016 ◽  
Vol 87 (19) ◽  
pp. 2407-2419 ◽  
Author(s):  
Qingqing Zhou ◽  
Jingchun Lv ◽  
Yu Ren ◽  
Jiayi Chen ◽  
Dawei Gao ◽  
...  

This study presented a simple and environmentally friendly method of in situ synthesis of silver nanoparticles (AgNPs) on cotton fabrics for durable ultraviolet (UV) protection and antibacterial activity using Aloe vera leaf extraction (AVE) as a reducing and stabilizing agent. Cotton fabrics were pretreated in water, and then immersed in AgNO3 and AVE, respectively. Cotton fabrics were characterized by small angle X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis, UV protection, antibacterial activity, and laundering durability. Comparing with the smooth surface of the control cotton fabric, SEM and energy dispersive X-ray spectrometry (EDX) results showed that there were a considerable number of Ag2O and AgNPs loading on the surface of the pretreated and Ag loaded cotton fabrics. The XRD pattern indicated, respectively, the existence of Ag2O and AgNPs, the structures of which were similar to JCPDS File No.65-3289 and JCPDS File No. 01-071-4613 on the pretreated and Ag loaded cotton fabrics. The pretreated and Ag loaded cotton fabrics showed excellent UV protection, antibacterial activity, and laundering durability, especially the Ag loaded cotton fabric, of which the UV protection factor value and transmission of UVA were 148 and 1.11%, respectively, after 20 washing cycles, and the clear zone width was more than 4 mm against E. coli or S. aureus. AgNPs facilitated the improvement of the thermal property of the cotton fabrics. Thus this facile in situ reduction of AgNPs with AVE may bring a promising and green strategy to produce functional textiles.


Author(s):  
Washington C.M. Gomes ◽  
Alcides de Oliveira Wanderley Neto ◽  
Patrícia Mendonça Pimentel ◽  
Dulce Maria de Araújo Melo ◽  
Fabiana Roberta Gonçalves e Silva

2014 ◽  
Vol 61 (5) ◽  
pp. 319-327 ◽  
Author(s):  
Mohamed Gobara ◽  
Mohamed Shamekh

Purpose – This paper aims to study both the mechanical properties and the corrosion behavior of the synthesized in situ (TiC-TiB2) particulates/AZ91 magnesium matrix composite and compare the results with that of the conventional AZ91D alloy. Design/methodology/approach – Scanning electron microscope (SEM) equipped with energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD) were used to study the surface morphology and crystalline structure. Mechanical compression tests were used to investigate the mechanical performance according to ASTM E9-89a. The corrosion behavior of the synthesized magnesium alloy was examined using both electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques in dilute Harrison solutions. Findings – The microstructure of the Mg composite showed a uniform distribution of reinforcing phases. Also, the reinforcing phases were formed without residual intermediate phases. The addition of titanium and boron carbides not only enhanced the mechanical properties of the matrix but also improve its corrosion behavior. Originality/value – This is the first time that magnesium matrix composite has been to synthesized with TiC and TiB2 particulates starting from starting from Ti and B carbides powder without adding aluminium using practical and low-cost technique (in situ reactive infiltration technique). This paper studies the corrosion behavior of synthesized Mg matrix in dilute Harrison solution and compares the results with that of conventional AZ91D.


2010 ◽  
Vol 113-116 ◽  
pp. 1712-1715
Author(s):  
Cheng Yu Wang ◽  
Chang Yu Liu ◽  
Jian Li

The preparation of hydrophobic CaCO3-wood composite through a double-diffusive method using dodecanoic acid as organic substrate is demonstrated. The product was characterized by the contact angle analysis, X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR) and scanning electron microscope (SEM). The mechanical properties of the product were measured. The results show that the synthesized CaCO3 fills in the wood cell and covers the surface of wood. The CaCO3-wood composite is hydrophobic. The mechanical properties of wood composite have significantly increased.


1969 ◽  
Vol 39 (6) ◽  
pp. 560-567 ◽  
Author(s):  
D. Meimoun ◽  
A. Parisot

The introduction of elastomeric substances between the cellulose fibrils and/or histological elements of cotton fibers could lead to wrinkle-resistant cottons. Such substances, polyenes obtained by polymerization in situ after inclusion within the structure, are unable to penetrate the intermolecular structure, but are able to link together the elements of the fiber. This might result in a fiber with greater delayed elastic recovery and reduced permanent set, permitting wrinkle recovery of cotton fabrics to be increased. The study of optimum reaction parameters resulted in a reproducible process for including the polymer. The location of the polymer has been determined through the development of a new method for revealing the structure of cellulose. The desired mechanical properties of woven treated fabrics are improved, as indicated by various measurements. The first results concerning single fibers seem to corroborate the preceding.


2020 ◽  
Vol 39 (19-20) ◽  
pp. 703-720
Author(s):  
Diego Saenz-Castillo ◽  
María I Martín ◽  
Vanessa García-Martínez ◽  
Abhiram Ramesh ◽  
Mark Battley ◽  
...  

Three different out-of-autoclave manufacturing processes of CF/poly-ether-ether-ketone thermoplastic composites were characterized, including innovative laser-assisted automated fibre placement with in situ consolidation. Characterization techniques included differential scanning calorimetry, ultrasonic non-destructive testing and matrix digestion, in addition to 3D X-ray microcomputed tomography to investigate the void distribution, size and shape. The results revealed that in situ consolidation process can lead to the accumulation of large voids between the upper layers. Interlaminar shear, in-plane shear, tensile and flexure testing were used for mechanical evaluation. A reduction in the mechanical properties was observed for in situ consolidation laminates when compared to the other out-of-autoclave methods. The drop in mechanical properties of in situ consolidation laminates was mainly attributed to the differences found in void distribution and size. Optimization of processing parameters along with higher quality prepreg raw material could be of assistance for the improvement of mechanical properties of in situ consolidation structures.


2020 ◽  
Vol 1 (1) ◽  
pp. 51-58
Author(s):  
Sharmila Pradhan ◽  
Rajeswori Shrestha ◽  
Khuma Bhandari

This research is focused on bio-synthesis of Copper nanoparticles (CuNPs) using lemon extract to study the effect of various parameters on synthesis and to explore antibacterial activity. The biomolecules present in lemon extract act as self reducing and stabilizing agent. The synthesis of CuNPs was found to be affected by various parameters like volume of the lemon extract, concentration of the precursor and the temperature etc. Preliminary characterization of formation of nanoparticles were done by color change and UV-visible (UV-vis) spectroscopy. Elemental composition of the prepared sample was determined via Energy Dispersive X-ray (EDX) Spectroscopy. Presence of important functional groups associated with biomolecules is well characterized by Fourier Transform Infrared spectroscopy (FTIR). Scanning Electron Microscopy (SEM ) revealed the formation agglomerated CuNPs of different shape and sizes and the X-ray diffraction pattern showed the formation of purely crystalline nature of CuNPs. Finally, agar well diffusion method showed that CuNPs have potential antibacterial activity against Gram-ve bacteria compared to Gram +ve bacteria.


2015 ◽  
Vol 88 (1) ◽  
pp. 138-146 ◽  
Author(s):  
Rouhollah Bagheri ◽  
Reza Darvishi

ABSTRACT In this study, polyurethane (PU)/organomodified montmorillonite (cloisite®30B) is synthesized via in situ polymerization by reaction of an ether-based prepolymer with the isocyanate end groups and adiamine chain extender (4, 4-methylene-bis(2-chloroaniline)) in the presence of different amounts of nanoparticles dispersed in the prepolymer matrix by an ultrasonic mixer for 1 h. The synthesized polymers are cast on a pretreated carbon steel sheet and cured at 120 °C in an oven. The PU and its composites have been characterized by using Fourier transform infrared spectroscopy, X-ray diffraction (XRD), and mechanical testing. The XRD analysis of the cured samples containing 1 to 3 wt% cloisite30B showed intercalation segments in the silicate layers and exfoliation for 0.5 wt% nanoparticles. The highest mechanical properties were obtained using the cured exfoliated silicate layer sample. A twofold increase in the ultimate tensile strength and a 2.3 times increase in the adhesion strength were found for 0.5 wt% organoclay/PU as compared with that of pure PU. In addition, the exfoliated structure sample exhibited a 16% reduction in abrasion compared with that of pure PU.


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