Novolac resin based two polymer networks were synthesized for the effective removal of azo dye molecules from aqueous solution.

Synthesis of novolac resin based novel network polymer 1 based on the reaction between novolac epoxy resin and ethylenediamine has been achieved for the first time and its sorption characteristics toward methyl orange as azo dye source have been investigated.

Background: Hybrids, composed of silver nanoparticles (AgNPs) dispersed inside a polymer matrix thus combining properties of both the components offer antibacterial activity and several advantages. Nevertheless, the development of antibacterial hybrid material comprising both novolac type phenolic resin and AgNPs remains one of the untouched issues in human healthcare. Objective: We report herein the simple preparation of hybrid derived from functionalized novolac resin and AgNPs. The hybrid was tested for antibacterial activity towards Gram-positive and Gramnegative bacteria. Method and Results: Preparation and characterization of functionalized novolac resin and hybrid were achieved. Gram-positive bacteria (Staphylococcus aureus MTCC 3160, Staphylococcus epidermidis NCIM2493, Bacillus subtilis) and Gram-negative bacteria (Pseudomonas aeruginosa ATCC27853, Escherichia coli) were used to test the bactericidal efficiency of hybrid. The antibacterial effectiveness of hybrid was determined in terms of the minimum inhibitory concentration (MIC). In addition, treatment with hybrid caused cytoplasmic contents leakage evidencing membrane damage. Conclusion: The hybrid developed thus could provide opportunities to fabricate a wide range of antibacterial functional materials for different purposes in human health associated sectors.

The hazardous consequences of azo dye organics on the environment and human health motivate the development of new sorbent materials for their elimination from wastewater. The purpose of this work is to prepare pyridine‐rich novolac resin‐based network material 1 as effective adsorbent for the removal of azo dye pollutants, methyl orange (MO), orange‐II (OII) and orange‐G (OG) azo dyes from aqueous solution at a wide range of pH (acidic‐neutral‐basic conditions). Both electrostatic interaction and physical forces are suggested to be involved during adsorption of azo‐dyes onto tailored adsorbent. Besides, dye‐adsorbed 1 was effectively desorbed by dil H2SO4 and recycled, which is promising for its practical application in the treatment of dye contaminated water.

Iron(III) loaded novolac-based network adsorbents 1 and 2 were studied for efficient removal of azo-dye pollutants from aqueous solutions. The adsorption behavior was evaluated by using methyl orange and orange-G as model azo dyes. The effect of parameters such as contact time and initial dye concentration on the adsorption of azo dyes was studied. The results showed that loading of Fe(III) onto the sorbent networks has noticeable effect on azo-dye sorption capacity. The adsorption equilibrium data were fitted to Freundlich isotherm model. Besides, the reusability of the dye loaded sorbents was investigated on adjusting pH of solutions.