Polyurethane foams doped with stable silver nanoparticles as bactericidal and catalytic materials for the effective treatment of water

Abstract

The development of reusable dual-purpose nanocomposite foams for catalytic and bactericidal water treatment is reported. Small non-aggregated silver nanoparticles were made using Intermatrix Synthesis inside a polyurethane foam, which was chosen as a suitable polymeric matrix due to its high chemical and mechanical stability and industrial applicability. The antibacterial activity of the obtained nanocomposites was evaluated against suspensions of Gram-negative bacteria (E. coli), showing ideal bactericidal features for being applied to water disinfection. The catalytic activity of nanocomposites was also evaluated through a model reaction carried out under flow conditions. The possibility of reusing the catalytic material was evaluated in 3 consecutive cycles and, for all of them, no significant loss of efficiency was found. Moreover, the leakage of the active species to the media was evaluated under accelerated ageing conditions (3 h in an ultrasonic bath) and a negligible amount of silver was found outside the matrix. The chemical stability of the as-prepared nanoparticles was also evaluated by XANES and any modification in the chemical structure of silver nanoparticles was detected, even after storing the samples for two years under dry conditionsPostprint (published version

3D Porous Polymeric-Foam-Supported Pd Nanocrystal as a Highly Efficient and Recyclable Catalyst for Organic Transformations

“…The peaks appearing at 2272, 2969, and 3272 cm −1 are ascribed to the presence of the −NCO, C−H, and N−H functional groups in PUF. 40 Interestingly, there is a significant red-shift of 54 cm −1 in the NCO peak upon loading of Pd NPs on PUF while all the other peaks remain unchanged (Figure 5h), suggesting that binding of Pd to the foam involves the NCO bond of polyurethane. The red-shift is attributed to partial donation of an oxygen lone pair to Pd, which weakens the NCO bond in the Pd-loaded PUF.…”

Quantitative Pore Characterization of Polyurethane Foam with Cost-Effective Imaging Tools and Image Analysis: A Proof-Of-Principle Study

“…They can be recycled or recovered after use to reduce production costs and increase material utilization efficiency [3]. Thermosetting polymers like PU foams are widely preferred due to their light weight, excellent biocompatibility, flexible mechanical properties, and the presence of a urethane linkage (–NH–CO–O–) that bonds easily with nanoparticles such as silver nanoparticles (AgNPs) [4,5,6,7,8,9,10]. Also, PU foams have the capability of delivering a wide range of cell structures, rigidity, strength, and durability.…”

“…Many publications [4,6,12,21,23,24,25] have demonstrated that PU foams exhibit high stability against chemical degradation, high mechanical durability, significant cushion properties, good swelling behavior, ease of separation from a solution, and are also some of the most inexpensive available polymer products. Several two-dimensional, relatively expensive, low-throughput, and complex imaging tools have been used for porous material characterization including optical microscopy, scanning electron microscopy (SEM), field emission SEM (FESEM), and transmission electron microscopy (TEM) [26].…”

Recent advance in antibacterial activity of nanoparticles contained polyurethane

“…These properties can be modified for specific applications just by changing the formulation and adjusting the reaction conditions during the preparation procedure and, interestingly, their physical and chemical characteristics can be improved through a combination of various additives during the synthesis (polymerization) process . Specifically, the incorporation of nanomaterials (i.e., metal nanoparticles, NPs) could significantly improve the properties of PU materials and their further applicability …”

“…However, their mechanism of action is not yet clearly understood, and a suggested mechanism of Ag NPs cytotoxicity toward the bacterial cell is presented in Figure . Silver is a noble metal with high biocompatibility, electrical and thermal conductivity, and excellent resistance to oxidation, which gives it various applications such as an antimicrobial filters, medical devices, protective cloths, chemical sensors, and water disinfectants …”