fingerprints are a commonly exploited type of evidence and can be crucial in a criminal investigation. The process of individualization or exclusion of a donor relies on the comparison of ridge detail characteristics between a fingermark, found at a crime scene, and reference fingerprints, collected under controlled conditions (either or not stored in a database). Although this process has been successfully used for over a century, fingermarks found at a crime scene are of limited value for a criminal trial if the corresponding reference fingerprint is not available, or the found fingermark is of poor quality. Fingerprints consist of donor secretion, mainly eccrine and sebaceous, of which the exact composition is likely influenced by many (both endogenous and exogenous) factors, including donor traits, habits and activities. Analysis of the chemical composition could thus potentially lead to the retrieval of donor information from those fingerprints that yielded no information in the traditional comparison process. The main aim of this dissertation was to determine what donor information can reliably and validly be derived from the chemical analysis of the fingerprint composition, in order to be used in forensic investigations...@en

Self-assembly of amphiphilic block copolymers in aqueous solution provides a versatile tool to create complex and functional micelles with various nanostructures, such as spherical, cylindrical and bilayer structures. As an important class in these structures, nanofibrillar micelles have attracted growing interest due to their unique properties that can potentially mimic biological analogues. For example, a great number of nanofibrillar structures, such as actin filaments and collagen gels with filamentous structures, were found in nature systems and have greatly motivated researchers to mimic these systems with synthetic materials. Besides, precise spatiotemporal control and integration of these nanofibrillar structures will offer a powerful strategy for construction of new soft devices in the future. Therefore, in this thesis, we explore the ultra-long, stiff and quenched micelles of diblock copolymers and develop a hybrid approach combining self-assembly of block copolymers and micro-fabrication methods to manipulate these micelles for building soft devices.@en

This thesis describes the experimental development of new dynamic hydrogels based on reversible thiol conjugate additions. Redox-controlled hydrogels and self-healing injectable hydrogels have been achieved by introducing reversible thiol conjugate additions to crosslink polymers, leading to hydrogel formation. The overall objective in this thesis was to develop a new fuel-driven transient polymeric hydrogel formation system. Although this final aim was not entirely met, we developed several important concepts along the way, which are described in Chapters 2-5. Chapter 2 describes a new chemical reaction network for fuel-driven transient formation of covalent S-C bonds, based on redox-controlled conjugate addition and elimination. We found that the formation and breaking of covalent bonds in the reaction cycle can be realized in separate reactions, but side reactions hindered the operation in full cycle. If such problems would be solved, this CRN could have potential to be used to form fuel-driven polymer materials. Chapter 3 investigates the formation of a self-healing injectable hydrogel by introducing dynamic thiol-alkynone double addition crosslinks in a polymer network. Such dynamic hydrogels show self-healing and shear thinning properties, confirmed by rheological measurements, macroscopic self-healing, and injection tests. Good cytocompatibility of these hydrogels opens an opportunity for future biomedical applications such as tissue engineering and drug delivery. Chapter 4 describes a redox-controlled reversible thiol-alkynone double addition. First, we created a redox-responsive hydrogel by using such reversible addition for the formation of crosslinks in hydrogels. Second, based on this thiol-alkynone double addition, we developed a fuel-driven transient formation of thiol-alkynone double adduct on small molecules. Chapter 5 explores coupling and decoupling reactions of thiols to an azanorbornadiene bromo sulfone. A self-healing hydrogel can be formed by using azanorbornadiene bromo sulfone to couple two thiol groups together. Such hydrogels are also degradable, trigged by glutathione. Glutathione-triggered dye release experiments suggest this self-healing hydrogel is a potential carrier of drugs, cells or vaccines for biomedical applications. @en

Nature has inspired countless researchers in their quest to understand the phenomena we observe and utilise their findings to develop new technologies. This becomes especially apparent in systems chemistry, which heavily draws inspiration from natural systems in its pursuit for the understanding and development of chemical reaction networks (CRNs) with interesting properties. Today, CRNs play a big role in many sensors, amplification systems, transient materials, and more. Despite major advances in the field of CRNs, there is still a need for additional robust, versatile chemistries to allow for more diverse applications, both within systems chemistry and in other fields beyond, such as material science. This thesis aims to explore new applications of Dynamic Covalent Chemistry (DCvC)—typically utilised to make self-healing materials—in CRNs to allow for new applications drawing from the versatile chemistry used in DCv systems. @en

Nature is full of life, which is driven by the numerous biochemical processes that occur in living organisms. Many motifs are universal regardless of species, such as enzymatic networks, self-assembly and reaction-diffusion. This work examines the development of novel soft functional materials via self-assembly and reaction-diffusion approaches. The combination of these two principles from nature offers new possibilities for the development and structuring of soft matter. In our research, we investigated the application of the reaction-diffusion self-assembly approach to make patterned hydrogels and hydrogel objects. The dimensions of the patterns and objects that have been made range from centimeter scale to microscale. Also, we demonstrated various possibilities of chemical functionalization of patterns and objects. In another implementation, we showed that self-assembly combined with reaction-diffusion at the interface of two gels can be used to glue pieces of gel by forming a self-assembled fibrous network across the interface. This approach worked for different biological and polymeric gels and was supported with a numerical model. Finally, we developed a novel strategy to make an in vitro model of artificial plaque. An artificial plaque was made by loading gelatin/alginate polymeric film with liposomes. The prepared films showed similar liposomal distribution as porcine plaque. Also, the plaque was implantable as demonstrated in ex-vivo and in-vivo experiments. @en

Growing importance of hydrogels in various areas of human life has led to increasing need in controlling their properties, which is generally achieved by adjusting hydrogels shape and microstructure. Even though standard microfabrication and microstructuring techniques can be currently applied in hydrogel research, the variety of properties of hydrogel materials makes it difficult to employ any of these techniques universally. Furthermore, to produce hydrogel structures complex enough to mimic biological tissues, several structuring and microfabrication approaches on various length scales would need to be combined. The complexity and diversity of problems associated with such processes raises a whole set of multidisciplinary challenges. This doctoral dissertation explores novel approaches to structuring and fabrication of polymeric and supramolecular hydrogels by combining modern microfabrication techniques with molecular self-assembly and/or exploiting mutual incompatibility of certain hydrophilic polymers.@en

Smart materials are materials that are capable of responding in a programmable and predictive manner. Such materials respond to a broad variety of internal and external triggers and modulate one or more material properties accordingly. Common material responses are controlled release, color changes, morphological changes or changing the mechanical properties of the bulk material. Well known examples of smart materials in our life are chromoactive materials in sunglasses or windows that change color or transparency when subjected to (sun)light, self-healing concrete and plastics or shape memory materials being responsive to heat. Smart materials often reside in a stationary phase, where built-in molecular functionality can respond autonomously to a changing environment. A material’s response can be triggered by many different stimuli having a chemical nature (e.g. pH, salts and metals), biochemical nature (e.g. peptides, nucleic acids, metabolites and polysaccharides) or a physical nature (e.g. temperature, light, magnetic field and pressure). Materials constructed from polymers, particles or gels can be used for applications such as self-healing, sensing, tissue engineering and drug delivery. Smart materials described in this thesis are designed to respond to signaling molecules, UV light, gamma-radiation or mechanical force. In the following subsections these triggers will be discussed in detail.@en