Clay Nanoparticles Composite Membranes Prepared with Three Different Polymers: Performance Evaluation

Abstract

This paper presents the results obtained from the evaluation of clay nanoparticles as an additive for improving the characteristics and performance of composite membranes cast with polysulfone (PS), polyethersulfone (PES), and polyvinylidene fluoride (PVDF). Different concentrations of clay nanoparticles, ranging from 1 to 10% based on the polymer mass, were used to prepare all dope solutions. The addition of clay nanoparticles changed the internal pore morphology of membranes, which resulted in significant changes on their performance, regarding its water permeability, and fouling potential. The optimum nanoclay concentration for permeability enhancement was different for each polymer, 1.5%, 2.0%, and 6.0% for PS, PES, and PVDF, respectively. This difference can be attributed to the differences of polymer's hydrophobicity, based on the contact angle of a sessile water drop, which is higher for PVDF (PVDF is more hydrophobic than PS and PES). The flow improvement changed based on the main polymer. Significant changes in internal pore structure were observed for all membranes. The proportion of macrovoids was decreased and pores had a better connectivity across the cross section for PES and PS membranes. For PVDF membranes, the addition of nanoclay had a different effect on their microstructure. In this case, internal pores were 20% wider, factor that increased the average membrane porosity. The simultaneous evaluation of the clay nanoparticles used as an additive have clearly demonstrated its potential application for composite membrane production. It is also worth to note that the best way for identifying and evaluating the potential for an additive for membrane casting is considering its effects for different polymers, under the same casting conditions.

Comparison between two Polyethersulfone concentrations in hollow fiber ultrafiltration membranes. Is it worth to use more polymer?

“…The data obtained for MWCO were recorded up to PEG 150 kDa MW and the membranes were not able to remove 90% of this substance, which is the concept of MWCO. Thus, to estimate this important characteristic of membranes and knowing that the typical rejection curve is sigmoidal 31,32 , an extrapolation was made with the results (Fig. 5 and 6).…”

Using Taguchi Experimental Design to Calculate and Analyze Thermal Conductivity for (Polyacrylamide – Kaolin) Composite

“…The addition of nano-filler particles to polymer systems can have a significant effect in improving their mechanical and electrical properties as well as chemical and thermal resistance. These improvements are based on the surface chemistry of polymer, nano filter and dispersion quality of nanofillers because of the strong polymer and clay interactions [3,4]. There are scientific studies that dealt with the thermal properties of composite materials, including the temperature influence on the time period for formation of polyacrylamide graft starch/clay at pH = 8.…”

Síntese e modificação de membranas poliméricas condutivas com polianilina e nanopartículas de argila.

“…CARLOS MIERZWA et al, 2012a;DO NASCIMENTO et al, 2004;NARAYANAN et al, 2010;RODRIGUES et al, 2018;SOUNDARARAJAH;KARUNARATNE;RAJAPAKSE, 2009;WANG et al, 2019b).…”

“…Paralelamente, diversos estudos conduzidos pelo Centro Internacional de Referência em Reúso de Água (CIRRA) revelaram melhorias nas propriedades mecânicas, de fluxo e condutividade de membranas modificadas com nanoargila (MIERZWA et al, 2013;MORIHAMA et al, 2014;RODRIGUES et al, 2018), e polianilina (PIAIA, 2017), quando ambos os aditivos foram incorporados separadamente. Diante desses benefícios observados pelos autores, surgiu a proposta de investigar a interação sinérgica da PANI/CN em membranas de poli(éter sulfona), (PES).…”