The bio-molecules from various plant components and microbial species have been used as potential agents for the synthesis of silver nanoparticles (AgNPs). In spite of a wide range of bio-molecules assisting in the pr...The bio-molecules from various plant components and microbial species have been used as potential agents for the synthesis of silver nanoparticles (AgNPs). In spite of a wide range of bio-molecules assisting in the process, synthesizing stable and widely applicable AgNPs by many researchers still poses a considerable challenge to the researchers. The biological agents for synthesizing AgNPs cover compounds produced naturally in microbes and plants. More than 100 different biological sources for synthesizing AgNPs are reported in the past decade by various authors. Reaction parameters under which the AgNPs were being synthesized hold prominent impact on their size, shape and application. Available published information on AgNPs synthesis, effects of various parameters, characterization techniques, properties and their application are summarised and critically discussed in this review.展开更多
To render layered silicates miscible with polymer matrices, one must convert the normally hydrophilic silicate surface to an organophilic one, making the intercalation of polymeric chain between silicate layers possib...To render layered silicates miscible with polymer matrices, one must convert the normally hydrophilic silicate surface to an organophilic one, making the intercalation of polymeric chain between silicate layers possible. This can be done by ion-exchange reactions with cationic surfactants. Sodium montmorillonite (Na-MMT) was modified with several organic cationic surfactants. Organoclays with water soluble surfactants were prepared by the traditional cation exchange reaction. An alternative procedure was used to prepare organoclays with water insoluble salts. The basal spacing and thermal behavior of organoclays were characterized by X-ray diffraction, XRD and Thermogravimetric analysis, TGA respectively.展开更多
Light driven, photon mediated green synthesis of silver nano-particles (AgNPs) was carried out using aqueous silver nitrate solution (1 mM) and aqueous extract of almond (Prunus amygdalus). Experiments were carried ou...Light driven, photon mediated green synthesis of silver nano-particles (AgNPs) was carried out using aqueous silver nitrate solution (1 mM) and aqueous extract of almond (Prunus amygdalus). Experiments were carried out in dark, diffused sunlight and direct sunlight to study the influence of light intensity as well as by wrapping the reaction tubes with colored cellophane filters (violet, green, yellow and red) to investigate the effect of light color on AgNP synthesis. It was observed that the violet filter enhanced the AgNPs synthesis appreciably. The FTIR spectroscopic analysis confirmed participation of bio-molecules with hydroxyl and amide groups present in the almond extract as reducing and capping or stabilizing agents, respectively. Dynamic light scattering (DLS) studies revealed the particle size distribution of nano-particles as 2 – 400 nm, and scanning electron microscopy (SEM) confirmed their spherical shape with an average size of about 20 nm. Growth analysis of AgNPs revealed an increase in number of nano-particles with time, whereas their rate of growth decreased gradually. The AgNP suspension was stable even beyond 3 weeks.展开更多
文摘The bio-molecules from various plant components and microbial species have been used as potential agents for the synthesis of silver nanoparticles (AgNPs). In spite of a wide range of bio-molecules assisting in the process, synthesizing stable and widely applicable AgNPs by many researchers still poses a considerable challenge to the researchers. The biological agents for synthesizing AgNPs cover compounds produced naturally in microbes and plants. More than 100 different biological sources for synthesizing AgNPs are reported in the past decade by various authors. Reaction parameters under which the AgNPs were being synthesized hold prominent impact on their size, shape and application. Available published information on AgNPs synthesis, effects of various parameters, characterization techniques, properties and their application are summarised and critically discussed in this review.
文摘To render layered silicates miscible with polymer matrices, one must convert the normally hydrophilic silicate surface to an organophilic one, making the intercalation of polymeric chain between silicate layers possible. This can be done by ion-exchange reactions with cationic surfactants. Sodium montmorillonite (Na-MMT) was modified with several organic cationic surfactants. Organoclays with water soluble surfactants were prepared by the traditional cation exchange reaction. An alternative procedure was used to prepare organoclays with water insoluble salts. The basal spacing and thermal behavior of organoclays were characterized by X-ray diffraction, XRD and Thermogravimetric analysis, TGA respectively.
文摘Light driven, photon mediated green synthesis of silver nano-particles (AgNPs) was carried out using aqueous silver nitrate solution (1 mM) and aqueous extract of almond (Prunus amygdalus). Experiments were carried out in dark, diffused sunlight and direct sunlight to study the influence of light intensity as well as by wrapping the reaction tubes with colored cellophane filters (violet, green, yellow and red) to investigate the effect of light color on AgNP synthesis. It was observed that the violet filter enhanced the AgNPs synthesis appreciably. The FTIR spectroscopic analysis confirmed participation of bio-molecules with hydroxyl and amide groups present in the almond extract as reducing and capping or stabilizing agents, respectively. Dynamic light scattering (DLS) studies revealed the particle size distribution of nano-particles as 2 – 400 nm, and scanning electron microscopy (SEM) confirmed their spherical shape with an average size of about 20 nm. Growth analysis of AgNPs revealed an increase in number of nano-particles with time, whereas their rate of growth decreased gradually. The AgNP suspension was stable even beyond 3 weeks.
