Adsorption characteristics and mechanisms of water-soluble polymers (PVP and PEG) on kaolin and montmorillonite minerals

The excessive use and accumulation of water-soluble polymers (WSPs, known as “liquid plastics”) in the environment can pose potential risks to both ecosystems and human health, but the environmental fate of WSPs remains unclear. Here, the adsorption behavior of WSPs with different molecular weight on kaolinite (Kaol) and montmorillonite (Mt)...

Tuning Nanopores in Tubular Ceramic Nanofiltration Membranes with Atmospheric-Pressure Atomic Layer Deposition: Prospects for Pressure-Based In-Line Monitoring of Pore Narrowing

Atomic layer deposition (ALD) is known for its unparalleled control over layer thickness and 3D conformality and could be the future technique of choice to tailor the pore size of ceramic nanofiltration membranes. However, a major challenge in tuning and functionalizing a multichannel ceramic membrane is posed by its large internal pore...

Thermal pre-processing before extraction of polyhydroxyalkanoates for molecular weight quality control

Past studies have repeatedly demonstrated the technical feasibility to produce polyhydroxyalkanoate (PHA) using bacterial biomass of mixed microbial cultures (MMCs). Commercial quality grades of poly(3-hydroxybutyrate-co-3-hydroxyvalerate), PHBV, can be produced with control of average monomer composition. However, demonstration of PHBV...

Diffusion of Soluble Organic Substrates in Aerobic Granular Sludge: Effect of Molecular Weight

Aerobic granular sludge (AGS) is an advanced biofilm-based technology for wastewater treatment. Diffusion of substrates into the granules is a key aspect of this technology. Domestic wastewater contains soluble organic substrates of different sizes that could potentially diffuse into the granules. In this study, the relation between the...

Adsorption of humic acid fractions by a magnetic ion exchange resin

Natural organic matter in waters varies in different fractions. To better understand the removal of different fractions by a magnetic ion exchange (MIEX) resin and the mechanism behind it, this study investigated adsorption kinetics, equilibrium and thermodynamics of humic acid (HA) fractions with different hydrophilic-hydrophobic properties...

Extraction of low molecular weight polyhydroxyalkanoates from mixed microbial cultures using bio-based solvents

(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) obtained from waste/wastewater using a mixed microbial culture (MMC) usually varies in its properties due to daily variation in the waste/wastewater composition applied as feedstock. In the current study, the average molecular weight (MW) of PHBV was purposely reduced from about 1 MDa to about...

Modeling the antifouling properties of atomic layer deposition surface-modified ceramic nanofiltration membranes

This work investigates the enhancement of antifouling properties of ceramic nanofiltration membranes by surface modification via atomic layer deposition (ALD) of TiO₂. Feed solutions containing bovine serum albumin (BSA), humic acid (HA) and sodium alginate (SA) were used as model foulants. The classic fouling mechanism models and...

Process conditions affect properties and outcomes of polyhydroxyalkanoate accumulation in municipal activated sludge

The developments of mixed culture polyhydroxyalkanoate production has been directed to maximize the biomass PHA content with limited attention to polymer quality. Direct comparison of PHA accumulation literature is challenging, and even regularly contradicting in reported results, due to underlying differences that are not well expressed. A...

The photostability and peel strength of ethylene butyl acrylate copolymer blends for use in conservation of cultural heritage

Materials, both natural and synthetic, are used as adhesives or consolidants during the conservation of cultural objects. However, few adhesives have been formulated specifically for the needs of cultural heritage. This article describes a study of the stability of ethylene butyl acrylate copolymers as well as blends of these polymers with low...

Nano-indentation response of ultrahighmolecular weight polyethylene (UHMWPE): A detailed analysis

Nano-indentation, a depth sensing technique, is a useful and exciting tool to investigate the surface mechanical properties of a wide range of materials, particularly polymers. Knowledge of the influence of experimental conditions employed during nano-indentation on the resultant nano-mechanical response is very important for the successful...

Biomimetic Strain-Stiffening Self-Assembled Hydrogels

Supramolecular structures with strain-stiffening properties are ubiquitous in nature but remain rare in the lab. Herein, we report on strain-stiffening supramolecular hydrogels that are entirely produced through the self-assembly of synthetic molecular gelators. The involved gelators self-assemble into semi-flexible fibers, which thereby...

Ceramic nanofiltration for direct filtration of municipal sewage

Worldwide population growth, water scarcity, and climate change contribute to an urgent need for alternative water sources for irrigation water, industry water, and, in some countries even, drinking water. The implementation of municipal sewage reclamation is an upcoming trend in water treatment. The use of municipal sewage has the advantage of...

Material Driven Design: Designing a product from residual Dyneema® production fibres.

This master’s thesis is a collaboration between DSM Dyneema and the Circular Design Lab, a part of the Faculty of Industrial Design Engineering at the Delft University of Technology. DSM Dyneema is a business group within the large Dutch multinational DSM N.V. They looking into means of making their business practice more suited to a future in a...

The photo-stability of acrylic tri-block copolymer blends for the consolidation of cultural heritage

A variety of adhesives are used for the conservation of paintings. These materials include natural adhesives such as animal glues, waxes, and gums which may chemically degrade over time resulting in unwanted discoloration and mechanical failure. Synthetic adhesives have been introduced to address these concerns. However, most consolidating...

Quantifying defects in ceramic tight ultra- and nanofiltration membranes and investigating their robustness

One of the perceived benefits of ceramic membranes is their robustness, which makes them suitable for treating high organic load waste streams. In particular, ceramic tight ultrafiltration (tUF) and nanofiltration (NF) form an important barrier against small colloids and organic molecules. In order to achieve this barrier, the quality of the...

Effect of homogeneous acidic catalyst on mechanical strength of trishydrazone hydrogels: Characterization and optimization studies

Characterization utilizing X-ray photoelectron spectroscopy (XPS) revealed the presence of all the expected elements found in trishydrazone hydrogels (3). Morphological study on confocal laser scanning microscopy (CLSM) and atomic force microscopy (AFM) revealed the branching and bundling of fibers that led hydrogels network as well as the...

Drawing behavior of UHMWPE films made from solution casting: Influence of solvent quality

Ultra-High Molecular Weight Polyethylene (UHMwPE) fibers are well known for their very high specific mechanical properties such as tensile strength and Young’s modulus. The solution spinning/solid state drawing process invented in the late 70s at DSM enables the production of these UHMwPE fibers with outstanding mechanical properties. The...