Biopolymer nanocomposites: lessons from structure-property relationships

The urgent need to address sustainability within material science, driven by global environmental concerns over pollution, climate change, and resource scarcity, has led to a growing interest in bio-based materials. This thesis explores the potential of biopolymers as alternatives to non-renewable resources, specifically the ones derived from...

Enhancement of fire resistance and mechanical performance of polypropylene composites containing cellulose fibres and extracellular biopolymers from wastewater sludge

In the present research, a bio-based flame retardant (FR) was prepared using a biopolymer derived from wastewater sludge to improve the fire performance of polypropylene (PP). Extracellular polymeric substances (EPS), which were extracted from wastewater aerobic granular sludge, were absorbed into cellulose-based fibres, such as flax and...

Influence of environmental conditions on accumulated polyhydroxybutyrate in municipal activated sludge

Poly(3-hydroxybutyrate) (PHB) was accumulated in full-scale municipal waste activated sludge at pilot scale. After accumulation, the fate of the PHB-rich biomass was evaluated over two weeks as a function of initial pH (5.5, 7.0 and 10), and incubation temperature (25, 37 and 55 °C), with or without aeration. PHB became consumed under aerobic...

Polyhydroxyalkanoate production by municipal waste activated sludge: Tackling scaling-up process challenges

Microbes are the gears that sustain all forms of life in planet Earth and are expected to become key players in the transition towards a more sustainable society. In this thesis, microbes from sewage sludge are used for the production of polyhydroxyalkanoates, biodegradable polymers that have the potential to replace<br/>many of the petroleum...

Tuning the rheological properties of kaolin suspensions using biopolymers

Kaolin based suspensions have wide range of applications such as slurry wall, drilling fluids, adhesives, cosmetics, refractories and pharmaceuticals, due to their abundance in nature, low cost and non-swelling nature. On the other hand, the unique properties (i.e., biodegradability) of biopolymers make them suitable candidate for variety of...

A review on recovery of extracellular biopolymers from flocculent and granular activated sludges: Cognition, key influencing factors, applications, and challenges

A reasonable recovery of excess sludge may shift the waste into wealth. Recently an increasing attention has been paid to the recycling of extracellular biopolymers from conventional and advanced biological wastewater treatment systems such as flocculent activated sludge (AS), bacterial aerobic granular sludge (AGS), and algal-bacterial AGS...

Quantification of polyhydroxyalkanoate accumulated in waste activated sludge

Polyhydroxyalkanoate accumulation experiments at pilot scale were performed with fullscale municipal waste activated sludge. Development of biomass PHA content was quantified by thermogravimetric analysis. Over 48 h the biomass reached up to 0.49 ± 0.03 gPHA/gVSS (n=4). Samples were processed in parallel to characterise the distribution of...

Systematic solvent screening and selection for polyhydroxyalkanoates (PHBV) recovery from biomass

The biotechnological production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) derived from organic waste streams by mixed microbial communities is well established at the pilot-level. However, there is limited research on the recovery of the biopolymer from the microbial biomass, while its impact on product quality and product costs...

Exploring the Limits of Polyhydroxyalkanoate Production by Municipal Activated Sludge

Municipal activated sludge can be used for polyhydroxyalkanoate (PHA) production, when supplied with volatile fatty acids. In this work, standardized PHA accumulation assays were performed with different activated sludge to determine (1) the maximum biomass PHA content, (2) the degree of enrichment (or volume-to-volume ratio of PHA...

Translocation of DNA through Ultrathin Nanoslits

2D nanoslit devices, where two crystals with atomically flat surfaces are separated by only a few nanometers, have attracted considerable attention because their tunable control over the confinement allows for the discovery of unusual transport behavior of gas, water, and ions. Here, the passage of double-stranded DNA molecules is studied...

Scaling-up microbial community-based polyhydroxyalkanoate production: status and challenges

Conversion of organic waste and wastewater to polyhydroxyalkanoates (PHAs) offers a potential to recover valuable resources from organic waste. Microbial community-based PHA production systems have been successfully applied in the last decade at lab- and pilot-scales, with a total of 19 pilot installations reported in the scientific...

Cellular Solids Based on Biopolymer Nanocomposites: For Hypersonic Heat Shields Aboard Sounding Rockets

The society of Delft Aerospace Rocket Engineering (DARE) aims at launching the Stratos IV sounding rocket to an apogee of 100km; thus cementing their place as one of the few student teams that have had the unique opportunity to design and build a rocket that is capable of reaching the frontiers of space. In doing so, DARE has entered flight...

A minimal-length approach unifies rigidity in underconstrained materials

We present an approach to understand geometric-incompatibility–induced rigidity in underconstrained materials, including subisostatic 2D spring networks and 2D and 3D vertex models for dense biological tissues. We show that in all these models a geometric criterion, represented by a minimal length ℓ¯min, determines the onset of prestresses and...

Biopolymer scleroglucan as an emulsion stabilizer

In this study, we investigated the Stabilization of bitumen emulsions by scleroglucan, a rigid triple-helix forming biopolymer, in combination with a pH-sensitive cationic surfactant. Various aspects of the emulsification process and the final composition influence the Stabilization. We examined two different methods to add scleroglucan to...

CoRncrete: A corn starch based building material

Starch is a natural polymer which is commonly used as a cooking ingredient. The renewability and bio-degradability of starch has made it an interesting material for industrial applications, such as production of bioplastic. This paper introduces the application of corn starch in the production of a novel construction material, named CoRncrete...

The Real-time City: life in a fully adaptable environment

The Real-time City is a city on demand, shaped by customization over time. Inhabitants can shape the content of the city and their personal spaces according to their desires. As situations are continuously changing, the city has to update itself in real-time; analysing the given input, applying parameters and act upon these changing situations....

Analysis of Alginate-like Exopolysaccharides for the Application in Enhanced Oil Recovery

Alginate-like exopolysaccharides (ALE) can be extracted from granular sludge, which is produced during aerobic granular sludge waste water treatment as a waste product. Processing the waste is a costly operation. It is believed that ALE consist mostly of alginates. The chemical and mechanical properties of alginates are potential for the...

Biopolymer Production by Bacterial Enrichment Cultures Using Non-Fermented Substrates

Polyhydroxyalkanotes (PHAs) are naturally occurring polymers synthesized by a wide range of microorganisms. Their physiological role is to act as carbon and energy reserves, and their mechanical and physical properties are similar to those of petrochemical plastics. PHAs can be synthesized from renewable materials and they are biodegradable....