Pectin bionanocomposite films filled with various concentrations of two different types of halloysite nanotubes were prepared and characterized in this study as potential films for food packaging applications. The two types of halloysite nanotubes were long and thin (patch) (200-30 000 nm length) and short and stubby (Matauri Bay) (50-3000 nm length) with different morphological, physical, and dispersibility properties. Both matrix (pectin) and reinforcer (halloysite nanotubes) used in this study are considered as biocompatible, natural, and low-cost materials. Various characterization tests including Fourier transform infrared spectroscopy, field emission scanning electron microscopy, release kinetics, contact angle, and dynamic mechanical analysis were performed to evaluate the performance of the pectin films. Exceptional thermal, tensile, and contact angle properties have been achieved for films reinforced by patch halloysite nanotubes due to the patchy and lengthy nature of these tubes, which form a bird nest structure in the pectin matrix. Matauri Bay halloysite nanotubes were dispersed uniformly and individually in the matrix in low and even high halloysite nanotube concentrations. Furthermore, salicylic acid as a biocidal agent was encapsulated in the halloysite nanotubes lumen to control its release kinetics. On this basis, halloysite nanotubes/salicylic acid hybrids were dispersed into the pectin matrix to develop functional biofilms with antimicrobial properties that can be extended over time. Results revealed that shorter nanotubes (Matauri Bay) had better ability for the encapsulation of salicylic acid into their lumen, while patchy structure and longer tubes of patch halloysite nanotubes made the encapsulation process more difficult, as they might need more time and energy to be fully loaded by salicylic acid. Moreover, antimicrobial activity of the films against four different strains of Gram-positive and Gram-negative bacteria indicated the effective antimicrobial properties of pectin/halloysite functionalized films and their potential to be used for food packaging applications.

The necessity of benefiting a breakthrough in filtration technology has led to increasing attention in advanced functional nanosized materials such as nanofibers for filtering devices as a solution for providing water at lower energy costs. In this study, electrospun polyacrylonitrile (PAN) nanofibrous membranes were reinforced by 1, 2, and 3% w/w of halloysite nanotubes (HNTs) in order to improve their mechanical properties, thermal stability and water filtration performance for the possible application as water filtration membranes. Morphological analysis revealed the highly porous and nanofibrous structure of membranes which further confirmed by surface area analysis (BET). Incorporation of HNTs enhanced the mechanical properties of the membranes such as tensile strength and elongation at break (especially at 1% w/w HNTs) while resulted in significant improvement of their thermal properties. Moreover, PAN/HNTs membranes showed excellent oil/ water separation performance, while incorporation of HNTs led to increase in water flux rate, which is considered as a key point in water filtration membranes. Additionally, heavy metal ion adsorption performance of the membranes showed a significant increase by incorporation of 3% w/w HNTs. These results signified the potential of electrospun PAN/HNTs nanofibrous membranes to be used for water filtration applications.

Water scarcity has become a global systemic risk, prompting the development of more efficient filtration technologies. Recently, increasing attention has been given to low cost membrane materials such as polyacrylonitrile (PAN) nanofibers for water filtration. In this study, electrospun PAN nanofibrous membranes were functionalized with zinc oxide (ZnO) nanoparticles and coated with a layer of electrospun chitosan (Cs), in order to improve the mechanical properties, and anti-bacterial and water filtration performance of the membranes. Morphological analysis revealed that the PAN/ZnO-Cs membranes featured a structural hierarchy comprising a layer of highly porous nanofibrous PAN membranes and a less fibrous and thinner layer of a Cs coating. Addition of the Cs layer increases the tensile strength and elastic modulus of the membranes. Results acquired from a water permeability test indicated that the bi-layer membranes possessed adequate transport properties for typical membrane applications. Furthermore, the additional Cs layer and ZnO nanoparticles significantly improved the heavy metal ion adsorption performance of the PAN membranes. Moreover, the efficiency of the PAN/ ZnO-Cs membrane for bacteria filtration has a log reduction value 2 orders of magnitude higher than PAN membranes, while the efficiency of these membranes for antibacterial action (i.e. in terms of log reduction value) is 6 orders of magnitude higher than PAN membranes. These results indicate the PAN/ ZnO-Cs membranes are structurally more stable than PAN membranes, better at bacteria removal during the filtration process and better at self-cleaning (i.e. membrane biofouling resistance) than PAN membranes, signifying the potential of these membranes for water filtration applications. Fig. 7 Bacteria filtration performance of electrospun membranes. Error bars represented AE1SD from triplicate. 53890 | RSC Adv., 2016, 6, 53882-53893 This journal is

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Extensive usage of long-lasting petroleum based plastics for short-lived application such as packaging has raised concerns regarding their role in environmental pollution. In this research, we have developed active, healable, and safely dissolvable alginate-pectin based biocomposites that have potential applications in food packaging. The morphological study revealed the rough surface of these biocomposite films. Tensile properties indicated that the fabricated samples have mechanical properties in the range of commercially available packaging films while possessing excellent healing efficiency. Biocomposite films exhibited higher hydrophobicity properties compared to neat alginate films. Thermal analysis indicated that crosslinked biocomposite samples possess higher thermal stability in temperatures below 120 °C, while antibacterial analysis against E. coli and S. aureus revealed the antibacterial properties of the prepared samples against different bacteria. The fabricated biodegradable multi-functional biocomposite films possess various imperative properties, making them ideal for utilization as packaging material.