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Green synthesis of nanoparticles (NPs) provides economic and environmental benefits as an alternative to chemical or physical methods. Furthermore, the surface properties of such NPs can be modulated by means of the functionalization with different groups making them suitable for various advanced functional applications including water pollutants removal using adsorption technique. In the present work, an eco-friendly synthesis route for nano-adsorbent SiO 2 NPs and subsequent surface modifications for enhanced adsorption capacity in removal of Cr(VI) ions from aqueous solution are reported. The green synthesis of SiO 2 NPs was carried out using simple bamboo leaves followed by surface modification with amine (A-SiO 2 ) and carboxylic (C-SiO 2 ) functional groups with aim to study the effect of functionalization on adsorption capacity. These nano-adsorbents were characterized by FTIR, SEM, XPS, BET, and zeta potential. and adsorption of Cr(VI) was studied at varying parameters i.e. NPs mass, contact time, and solution pH. The investigation shows interesting results revealing the importance of interactions between the surface functional groups on SiO 2 NPs and Cr(VI) species as well as experimental conditions for the choice of surface modifier to achieve a maximum adsorption capacity. The adsorption mechanism has been studied using Langmuir, Freundlich and Temkin adsorption isotherms. The maximum adsorption capacity has been achieved in the case of A-SiO 2 NPs which was found to 174 mg/g and much higher than that of SiO 2 and C-SiO 2 NPs attributed to the selective adsorption and pH conditions. Additionally, A-SiO 2 NPs exhibit excellent recyclability indicating their suitability for promising and long term potential applications. This study provides a novel, simple and cost-effective synthesis/surface engineering technology for producing high performance recyclable nano-adsorbents for adsorptive removal of Cr(VI)., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Green synthesis of nanomaterials is a sustainable, biologically safe, reliable, and eco-friendly approach. Green synthesis is beneficial to reduce the devastating effects of the traditional chemical synthesis methods and particularly aims at decreasing the usage of toxic chemicals. This review deals with the green synthesis of silica nanoparticles (SiO 2 NPs) with emphasis on the engineering surface properties for enhanced adsorption capability and their applications as novel nano-adsorbents for water pollutants removal. Green synthesized SiO 2 NPs have shown excellent adsorption properties with higher adsorption capacity of 150-200 mg/g and more than 95% removal for various toxic water pollutants along with reusability for more than 5 cycles. These SiO 2 NPs show fascinating physical and chemical properties i.e. tunable size (5 nm to more than 100 nm), low toxicity, biocompatibility, high porosity, higher specific surface area (500--700 m 2 /g) making them attractive/suitable for several applications in biomedical, agriculture, catalysis, construction, water treatment, etc. Commonly, highly pure SiO 2 NPs are synthesized from organic chemicals (very expensive and highly toxic in nature) as a precursor that led to high production costs, high energy consumption, and environmental hazards. On the other hand, green synthesis of SiO 2 NPs from natural resources like biomass that includes rice husk, bamboo leaves/stem, sugarcane bagasse, corn cobs, wheat straw, etc. is cost-effective, less toxic, and eco-friendly which has been discussed in detail. Furthermore, the effect of key synthesis parameters (i.e., temperature, time, concentration, pH, etc.) on the morphology, size, purity, and specific surface area of SiO 2 NPs have been summarized. Finally, the applications of SiO 2 NPs as nano-adsorbents for the removal of toxic water pollutants (i.e., heavy metal cations, anions, dyes, etc.) including the adsorption mechanisms along with the future scope, challenges, and suggestions have been discussed., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Poor solubility of newly developed drug molecules is the main problem in recent drug discovery research, so novel drug delivery approaches are being used to deliver these molecular entities for pharmacological action. Colloidal carriers (emulsion, suspensions, liposomes, polymer nanoparticles and solid lipid nanoparticles) have been used to administer poorly soluble drugs, but solid lipid nanoparticles are found to be the most reliable carriers for this type of drugs due to its advantages over other carriers. Solid lipid nanoparticles have the potential to solve the drug delivery problems with safe excipients used in its formulation. In this review all the aspects of solid lipid nanoparticles production, stability, characterization, differentiation based on route, preservation and storage have been discussed., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Solid lipid nanoparticles were prepared and studied for the possibility of entrapment of Paliperidone (PPN) an antipsychotic drug that can be used for the treatment of schizophrenia. Here we report the preparation of Paliperidone loaded solid lipid particles (SLNs) with Capmul GMS 50 K as lipid vehicle. SLNs were stabilized by a surfactant namely sodium deoxycholate which can also act as permeability enhancer. Final size of SLNs produced were approximately 200 nm which was confirmed by dynamic light scattering (DLS), atomic force microscopy (AFM) and transmission electron microscopy (TEM). SLNs appeared spherical in TEM images while dough nut like shape was observed by AFM. The entrapment efficiency of this system was found to be 55% with 4.15% of drug loading in lipid matrix. Structural characterization of SLNs by Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (XRD) and differential scanning calorimetric (DSC) analysis revealed that, there was no interaction of PPN with lipid and PPN was well dispersed in the lipid matrix without any crystallization., (Copyright © 2012 Elsevier B.V. All rights reserved.)