Publication on AWSensors technology

Fouling of Reverse Osmosis Membrane with Effluent Organic Matter: Componential Role of Hydrophobicity

/in , , /by

Authors: Noa Stein, Revital Sharon-Gojman, Meagan S. Mauter, Roy Bernstein and Moshe Herzberg

Journal: ACS ES&T Water (2023)

 

Abstract

Organic matter dissolved in tertiary effluents (effluent organic matter, EfOM) is the predominant organic membrane foulant in tertiary wastewater reverse osmosis (RO) desalination, ultimately causing biofouling. The interrelated effects of EfOM fractions of different hydrophobicity and polarity on membrane performance were studied by (i) examining each fraction’s overall effect on membrane permeability; (ii) analyzing the intrinsic hydraulic resistance induced by each fraction; (iii) studying their adsorption on the active layer of an RO membrane using a quartz crystal microbalance with dissipation monitoring (QCM-D); (iv) assessing their “dry” molecular mass when adsorbed on polyamide using localized surface plasmon resonance (LSPR) sensing; (v) analyzing their hydrodynamic radii by dynamic light scattering (DLS); and (vi) characterization using excitation–emission matrix (EEM) analysis and parallel-factor (PARAFAC) modeling. Hydrophobic and transphilic neutral fractions (containing ∼12.5% total organic carbon) have the greatest effect on membrane flux reduction and the highest hydraulic resistance and adhere most strongly to polyamide surfaces, resulting in the highest adsorbed “dry” mass. Therefore, in terms of their effect on RO permeate flux reduction, these fractions are the most detrimental in the EfOM mix. EEM analysis and associated PARAFAC modeling indicate that the main components causing this effect are mixtures of protein-like compounds, together with humic-like substances. Novel LSPR-based analysis elucidated the role of the fractions most detrimental to membrane permeability through measurement of dry mass surface concentration on a polyamide mimetic sensor. This study provides valuable insights into the roles of different EfOM fractions in RO membrane fouling and enhances our understanding of fouling during tertiary wastewater desalination.

Fouling of Reverse Osmosis Membrane with Effluent Organic Matter: Componential Role of Hydrophobicity

 

You may read the full paper here.

European Flag

Sensobac, biosensores para detección de bacterias viables en agua potable

/in , , /by

Advanced Wave Sensors S.L. (AWSensors), en el marco del programa “Proyectos Estratégicos en Cooperación“, ha contado con el apoyo de la Agència Valenciana de la Innovació y con la cofinanciación del fondo europeo FEDER para el desarrollo de un proyecto de investigación industrial en el campo de los biosensores. El proyecto lo lidera AWSensors, junto con la Universitat de Politècnica de València y la Empresa Mixta Valenciana de Aguas, S.A., comenzando en mayo de 2022 y finalizando en septiembre de 2024. El proyecto cuenta con un presupuesto total de 297.531,75 € con una subvención de 178.519,05 €.

El objetivo principal de este proyecto es desarrollar una nueva técnica analítica de biosensores para la detección temprana de biomarcadores ligados a presencia de bacterias en la red de distribución de agua potable que funcione como un sistema de alerta y vigilancia constante. La tecnología propuesta, basada en la tecnología sensora QCMD de AWSensors, supone una ventaja respecto a las tecnologías disponibles por su robustez, sensibilidad, detección directa en tiempo real, capacidad de análisis multianualito, bajo coste por ensayo, bajo coste por sensor, modularidad y su facilidad de uso.

Durante el transcurso del proyecto, se trabajará en la selección de un conjunto de biomarcadores que permitan su cuantificación y relación con la presencia y viabilidad de bacterias en aguas, se desarrollaron protocolos analíticos de validación primero a nivel de laboratorio y, posteriormente, sobre la plataforma biosensora desarrollada a tal efecto.

«Actuación susceptible de ser cofinanciada por la Unión Europea»

Publication on AWSensors technology

Tuning the water interactions of cellulose nanofibril hydrogels using willow bark extract

/in , , /by

Authors: Ngoc Huynh, Juan José Valle-Delgado, Wenwen Fang, Suvi Arola, Monika Österberg

Journal: Carbohydrate Polymers (2023)

 

Abstract

Cellulose nanofibrils (CNFs) are increasingly used as precursors for foams, films and composites, where water interactions are of great importance. In this study, we used willow bark extract (WBE), an underrated natural source of bioactive phenolic compounds, as a plant-based modifier for CNF hydrogels, without compromising their mechanical properties. We found that the introduction of WBE into both native, mechanically fibrillated CNFs and TEMPO-oxidized CNFs increased considerably the storage modulus of the hydrogels and reduced their swelling ratio in water up to 5–7 times. A detailed chemical analysis revealed that WBE is composed of several phenolic compounds in addition to potassium salts. Whereas the salt ions reduced the repulsion between fibrils and created denser CNF networks, the phenolic compounds – which adsorbed readily on the cellulose surfaces – played an important role in assisting the flowability of the hydrogels at high shear strains by reducing the flocculation tendency, often observed in pure and salt-containing CNFs, and contributed to the structural integrity of the CNF network in aqueous environment. Surprisingly, the willow bark extract exhibited hemolysis activity, which highlights the importance of more thorough investigations of biocompatibility of natural materials. WBE shows great potential for managing the water interactions of CNF-based products.

 

Cellulose nanofibrils (CNFs) are increasingly used as precursors for foams, films and composites, where water interactions are of great importance. In this study, we used willow bark extract (WBE), an underrated natural source of bioactive phenolic compounds, as a plant-based modifier for CNF hydrogels, without compromising their mechanical properties. We found that the introduction of WBE into both native, mechanically fibrillated CNFs and TEMPO-oxidized CNFs increased considerably the storage modulus of the hydrogels and reduced their swelling ratio in water up to 5–7 times. A detailed chemical analysis revealed that WBE is composed of several phenolic compounds in addition to potassium salts. Whereas the salt ions reduced the repulsion between fibrils and created denser CNF networks, the phenolic compounds - which adsorbed readily on the cellulose surfaces - played an important role in assisting the flowability of the hydrogels at high shear strains by reducing the flocculation tendency, often observed in pure and salt-containing CNFs, and contributed to the structural integrity of the CNF network in aqueous environment. Surprisingly, the willow bark extract exhibited hemolysis activity, which highlights the importance of more thorough investigations of biocompatibility of natural materials. WBE shows great potential for managing the water interactions of CNF-based products.

 

You may read the full paper here.

Publication on AWSensors technology

Tailoring Interactions of Random Copolymer Polyelectrolyte Complexes to Remove Nanoplastic Contaminants from Water

/in , , /by
Authors: Jeremy Wang, Curt Waltmann, Caroline Harms, Sumeng Hu, John Hegarty, Benjamin Shindel, Qifeng Wang, Vinayak Dravid, Kenneth Shull, John M. Torkelson, and Monica Olvera de la Cruz

Journal: Langmuir (2023)

 

Abstract

We investigate the usage of polyelectrolyte complex materials for water remediation purposes, specifically their ability to remove nanoplastics from water, on which there is currently little to no prior research. We demonstrate that oppositely charged random copolymers are effective at quantitatively removing nanoplastic contamination from aqueous solution. The mechanisms underlying this remediation ability are explored through computational simulations, with corroborating quartz crystal microbalance adsorption experiments. We find that hydrophobic nanostructures and interactions likely play an important role.

 

Tailoring Interactions of Random Copolymer Polyelectrolyte Complexes to Remove Nanoplastic Contaminants from Water

 

You may read the full paper here.

Publication on AWSensors technology

Trace Water Effects on Crystalline 1-Ethyl-3-methylimidazolium Acetate

/in , , /by

Authors: Ashlee Aiello, John R. Hoffman, Anthony P. Kotula, Lucas Q. Flagg, Ruipeng Li, and Jeremiah W. Woodcock

Journal: J. Phys. Chem. B (2023)

 

Abstract

Spontaneous room-temperature crystallization of 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]) was observed upon removal of trace water. Sample purity was confirmed using analytical nuclear magnetic resonance spectroscopy to ensure that trace water or other contaminants did not produce this observation. Raman spectroscopy and simultaneous quartz crystal microbalance/infrared spectroscopy measurements were used to study molecular reorganization during crystallization and decrystallization using trace water in the form of atmospheric moisture. These experimental results were supplemented with density functional theory calculations that indicate imidazolium cation ring stacking and side chain clustering with an exclusive arrangement of the acetate anion in the cation ring plane upon water removal. Crystal structure formation was confirmed using two-dimensional wide-angle X-ray scattering. This natural crystallization is attributed to the removal of trace water over extended periods of time and calls attention to the molecular-level role of water in the structure of hygroscopic ionic liquid systems.

You may read the full paper here.

Publication on AWSensors technology

Polyelectrolyte Complexes of Random Copolymers and their Applications in Environmental Remediation

/in , , /by

Author: Jeremy Wang

PhD Thesis: Northwestern University (March 2023)

 

Abstract

As polymer science has advanced as a field, so too have the uses for polymeric materials. We encounter polymers and plastics on a daily basis, and while their presence has greatly improved our quality of life, they have also had a profound and often negative impact on our environment. Plastic waste and pollution are currently problems of great concern, and recent trends in terms of micro– and nanoplastic pollution, and chemical pollution of water continue to exacerbate such worries. In this thesis, we explore how polyelectrolyte complexes of random copolymers can be used to effectively address some of these environmental concerns. The combination of charged interactions and disorder of polymer sequence can provide a novel combination of interactions which are well suited for removing contaminants from water, and even promoting the enzymatic degradation of plastic. The results obtained demonstrate that this research into new polymeric materials not only advances our understanding of fundamental polymer properties but yields relevant applications to the issues we encounter in the present day.

 

You may read the full text here.

Publication on AWSensors technology

Multispecies biofilms on reverse osmosis membrane dictate the function and characteristics of the bacterial communities rather than their structure

/in , , /by

Authors: Noya Ran, Gil Sorek, Noa Stein, Revital Sharon-Gojman, Moshe Herzberg, and Osnat Gillor

Journal: Environmental Research (2023)

 

Abstract

The main reason for the deterioration of membrane operation during water purification processes is biofouling, which has therefore been extensively studied. Biofouling was shown to reduce membrane performance reflected by permeate flux decline, reduced selectivity, membrane biodegradation, and consequently, an increase in energy consumption. Studies of biofouling focused on the identification of the assembled microbial communities, the excretion of extracellular polymeric substances (EPS), and their combined role in reduced membrane performance and lifetime. However, the link between the structure and function of biofouling communities has not been elucidated to date. Here, we provide a novel insight, suggesting that bacterial functions rather than composition control biofouling traits on reverse osmosis (RO) membranes. We studied the potential activity of RO biofilms at metatranscriptome resolution, accompanied by the morphology and function of the biofouling layer over time, including microscopy and EPS composition, adhesion, and viscoelastic properties. To that end, we cultivated natural multispecies biofilms in RO membranes under treated wastewater flow and extracted RNA to study their taxonomies and gene expression profiles. Concomitantly, the biofilm structure was visualized using both scanning electron microscopy and laser scanning confocal microscopy. We also used quartz crystal microbalance with dissipation to characterize the affinity of EPS to membrane-mimetic sensors and evaluated the viscoelasticity of the Ex-Situ EPS layer formed on the sensor. Our results showed that different active bacterial taxa across five taxonomic classes were assembled on the RO membrane, while the composition shifted between 48 and 96 h. However, regardless of the composition, the maturation of the biofilm resulted in the expression of similar gene families tightly associated with the temporal kinetics of the EPS composition, adhesion, and viscoelasticity. Our findings highlight the temporal selection of specific microbial functions rather than composition, featuring the adhesion kinetics and viscoelastic properties of the RO biofilm.

 

You may read the full paper here.

European Flag

AWSensors participa en el programa INVEST IN SPAIN

/in , /by

Advanced Wave Sensors S.L. (AWSensors) en el marco del Programa INVEST IN SPAIN, ha contado con el apoyo de ICEX y con la cofinanciación del fondo europeo FEDER para el desarrollo de su proyecto de investigación industrial en el campo de la funcionalización bioquímica de superficies. El objetivo de este proyecto era el desarrollo de protocolos de modificación de la superficie de los sensores QCMD comercializados por la empresa que limiten la adsorción inespecífica a la vez que maximicen las interacciones moleculares específicas.

Durante el transcurso del proyecto, se seleccionó un conjunto de reactivos potenciales en base a la investigación bibliográfica, se desarrollaron protocolos para modificar las superficies de los sensores y evaluar el desempeño de los sensores modificados; Se diseñaron y fabricaron herramientas dedicadas para ayudar en el proceso de superficie. La evaluación del rendimiento de los sensores QCMD modificados en su superficie condujo a la selección de un reactivo específico para el bloqueo de la adsorción no específica. Adicionalmente, estas modificaciones de la superficie se caracterizaron mediante ensayos de tipo inmunológicos (unión antígeno y anticuerpo modelo) para evaluar su utilidad.

Los protocolos desarrollados durante el transcurso del proyecto nos han permitido el desarrollo de un producto comercial, el sensor QCMD con superficie biotinilada, que esperamos introducirlo en el mercado a fines del verano de 2023. Este producto ofrecerá a los usuarios de nuestra tecnología mayores facilidades a la hora de adaptar la superficie del sensor al ensayo y moléculas necesarias para el desarrollo de los mismos.

   

Publication on AWSensors technology

Modifying last layer in polyelectrolyte multilayer coatings for capillary electrophoresis of proteins

/in , , /by

Authors: Sébastien Roca, Laurent Leclercq, Philippe Gonzalez, Laura Dhellemmes, Laurent Boiteau, Gaulthier Rydzek, and Hervé Cottet

Journal: Journal of Chromatography A (2023)

 

Abstract

Protein adsorption on the inner wall of the fused silica capillary wall is an important concern for capillary electrophoresis (CE) analysis since it is mainly responsible for separation efficiency reduction. Successive Multiple Ionic-polymer Layers (SMIL) are used as capillary coatings to limit protein adsorption, but even low residual adsorption strongly impacts the separation efficiency, especially at high separation voltages. In this work, the influence of the chemical nature and the PEGylation of the polyelectrolyte deposited in the last layer of the SMIL coating was investigated on the separation performances of a mixture of four model intact proteins (myoglobin (Myo), trypsin inhibitor (TI), ribonuclease a (RNAse A) and lysozyme (Lyz)). Poly(allylamine hydrochloride) (PAH), polyethyleneimine (PEI), ε-poly(L-lysine) (εPLL) and α-poly(L-lysine) (αPLL) were compared before and after chemical modification with polyethyleneglycol (PEG) of different chain lengths. The experimental results obtained by performing electrophoretic separations at different separation voltages allowed determining the residual retention factor of the proteins onto the capillary wall via the determination of the plate height at different solute velocities and demonstrated a strong impact of the polycationic last layer on the electroosmotic mobility, the separation efficiency and the overall resolution. Properties of SMIL coatings were also characterized by quartz microbalance and atomic force microscopy, demonstrating a glassy structure of the films.

 

You may read the full paper here.

Publication on AWSensors technology

Effect of Noise on Determining Ultrathin-Film Parameters from QCM-D Data with the Viscoelastic Model

/in , , /by

Authors: Diethelm Johannsmann, Arne Langhoff, Christian Leppin, Ilya Reviakine, and Anna M. C. Maan

Journal: Sensors (2023)

 

Abstract

Quartz crystal microbalance with dissipation monitoring (QCMD) is a well-established technique for studying soft films. It can provide gravimetric as well as nongravimetric information about a film, such as its thickness and mechanical properties. The interpretation of sets of overtone-normalized frequency shifts, Δf/n, and overtone-normalized shifts in half-bandwidth, ΔΓ/n, provided by QCMD relies on a model that, in general, contains five independent parameters that are needed to describe film thickness and frequency-dependent viscoelastic properties. Here, we examine how noise inherent in experimental data affects the determination of these parameters. There are certain conditions where noise prevents the reliable determination of film thickness and the loss tangent. On the other hand, we show that there are conditions where it is possible to determine all five parameters. We relate these conditions to the mathematical properties of the model in terms of simple conceptual diagrams that can help users understand the model’s behavior. Finally, we present new open source software for QCMD data analysis written in Python, PyQTM.

 

You may read the full paper here.