Facile synthesis of novel tough and highly flexible biodegradable membranes for water microfiltration

Abstract

Microporous polymeric membranes have found great applications in the area of water desalination and wastewater treatment, tissue engineering, drug delivery, and bone regeneration. The ability to create micro-size pores within a polymeric membrane allows for cavity formation that could form channels through which substances may permeate or percolate easily. The majority of these applications though, require micro-size porous membranes with small pore size and narrow pore-size distribution as to allow the control of the permeating substances or tissues. In the current work, an intricate and precise method was developed to generate micro-size porogen salt crystals with controlled micro-size distribution, which is then mixed with a specific biodegradable polymeric blend designed to offer both toughness and high flexibility for the production of microfiltration biodegradable membranes that can withstand the high pressures of large volumes of industrial wastewater undergoing filtration treatment. After casting, the porogen crystals are washed away rendering membranes with well-distributed micro-scale cavities. Using salt porogens offers a great advantage of no contamination to the environment since all salt particles are simply washed away. The ingenuity of this technique is that it allows the filtration of the wastewater at low or no pressures.

Three-dimensionally printed polylactic acid/cellulose acetate scaffolds with antimicrobial effect

“…According to previous reports, 28 the existence of hydrogen bonding between the –OH of CA and the –C O of PLA was attributed to limited extensibility of PLA chains. It was believed here that the increase of magnitude of modulus could be the consequence that the presence of 30% CA restrained the mobility of PLA chains via interface interaction of hydrogen bonds.…”

“…It was related to the repulsive forces between the two slightly hydrophobic polymers that further led to the decline of the G ′ and G ′′ of the polymeric blend. 28 Therefore, the excessive addition of CA had a negative effect on the printability of the ink. Hence, the results clearly demonstrated that the ink of PLA/CA at 70 : 30 weight ratio was the most desirable material for extrusion.…”

“… 27 Nevertheless, the cost associated with obtaining CA might be somehow expensive, although cellulose, as the raw material of CA, is considered the most abundant polymer on the earth. We find that PLA can possess a unique versatility after blending with CA, 28 and the formation of hydrogen bonding 3D network between PLA and CA lead the enhanced interface interaction, which signifies the stable 3D architecture without collapsing. 28,29 Therefore, in this study, we investigate the printability of the different compositions of PLA/CA pasted in DIW, and the effect of CA on the rheological behavior of the inks was discussed.…”

“…We find that PLA can possess a unique versatility after blending with CA, 28 and the formation of hydrogen bonding 3D network between PLA and CA lead the enhanced interface interaction, which signifies the stable 3D architecture without collapsing. 28,29 Therefore, in this study, we investigate the printability of the different compositions of PLA/CA pasted in DIW, and the effect of CA on the rheological behavior of the inks was discussed. The fabrication process of the antibacterial 3D objects was given in Scheme 1 .…”

Deploying Nanoparticle-Doped Polymeric Membranes in Treating Water Contaminated with Ciprofloxacin

“…The nanoporous membranes were prepared using the solvent casting technique with a mixture of PLA and PU as described in [15], with 10% cellulose acetate (CA) and 50% NaCl crystals (pore formers). They were then soaked in 0.1 M of the metal salt solution for three days on an orbital shaker, then added to a 0.5 M NaBH4 aqueous solution and was shaken for 24 h on an orbital shaker at room temperature to allow all the metal salt ions to be reduced to metal nanoparticles.…”