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The aim of my Ph.D. project was the development and synthesis of new near infrared absorbers suitable to be used as near infrared absorbing additives in laser welding of plastics. Laser welding is a technique for joining polymers in which laser light is absorbed and converted to heat. The converted heat melts the plastic and joins the two pieces. The work related to this project is described in chapters 1 to 3 During this project I spent 3.5 months at Massachusetts Institute of Technology as part of the exchange program in my PhD. Here I worked at a project aiming to develop a new responsive nanoparticle, to be used in protective gear. The work related to this project is described in chapter 4. The thesis is divided into 4 chapters describing the following subjects: Chapter 1 gives an introduction to the main aspects of processing polymers, how a plastic is formed, and some common additives used to form plastic. This chapter also contains a brief introduction to the principles in laser transmission welding. Finally this chapter contains a description of some already available absorbing additives for transmission laser welding. This chapter aims to give the reader the insight into the requirements for an additive used in plastic processing. Chapter 2 provides an overview of the already known dyes derived from croconic acid. This chapter describes the attempts to synthesize novel croconium dyes, and the synthesis of three new croconium dyes. This chapter also contains the synthesis of and experiments leading to the development of a commercially viable synthesis strategy of the lead compound. Chapter 3 contains a description of the custom equipment assembled to have in-house test capabilities. This chapter also describes the analysis data for the 3 synthesized candidates. Chapter 4 contains the details of the project I worked on while visiting prof. T: Swager’s laboratory at Massachusetts Institute of Technology. This chapter describes the aim of the project along with

Food inspection is a widespread measure for ensuring food quality, contents, and safety. The food inspection industry has deployed cameras and computer vision for a long time since they allow for automatic inspection and evaluation of food quality at a large scale. However, they fail to capture internal defects, which can arise due to natural and unnatural effects. X-ray imaging allows us to inspect the internals of a subject, thus countering the problem. The Adaptive X-ray InSpection (AXIS) project collaborates with multiple partners targeting utilizing X-ray imaging for food inspection. This thesis presents the University of Copenhagen’s part of the AXIS project: software for automated AI learning for X-ray-based classification. The main research areas are computer vision, machine learning, and reconfigurable hardware. Computer vision can counter the side-effects of X-ray imaging, resulting in clean images ready for machine learning. In recent years, machine learning has seen a rise in image processing due to its strong predictive power in recognizing patterns in seemingly complex imagery. To keep up with the high-throughput demands of food inspection, we employ reconfigurable hardware, or Field-Programmable Gate Arrays (FPGAs), as these favor pipelines are great at online processing and have been shown to be suitable for machine learning inference. This thesis presents an FPGA-based solution for the preprocessing steps of the X-ray images, a CPU/GPU- based implementation for the machine learning model, along with an outline for an FPGA-based machine learning inference solution. The implementations have had automation in mind, minimizing the required amount of user interaction. This thesis has spawned many student projects that have been supervised throughout the thesis while contributing to the field of reconfigurable hardware through open-source projects seeking to lift the level of abstraction in hardware programming.

We introduce bis-aryl croconamides as a new member in the family of dual hydrogen bonding anion receptors. In this study a series of croconamides are synthesised, and the selectivity for anion binding is investigated (Cl− > Br− > I− in CH2Cl2). The croconamides exhibit different structures in the crystal phase depending on the substituents on the aromatic rings, and furthermore, the crystal structure revealed the presence of tautomers. DFT calculations elucidated the complex structures formed upon addition of anion to the croconamides, confirming the order of association constants towards the halogen anions. The use of croconamides as organocatalysts in a proof-of-concept study is demonstrated in the formation of THP ethers. In addition to this, construction of a Hammet plot further elucidates the mechanism in action on formation of THP ethers, We introduce bis-aryl croconamides as a new member in the family of dual hydrogen bonding anion receptors. In this study a series of croconamides are synthesised, and the selectivity for anion binding is investigated (Cl- > Br- > I- in CH2Cl2). The croconamides exhibit different structures in the crystal phase depending on the substituents on the aromatic rings, and furthermore, the crystal structure revealed the presence of tautomers. DFT calculations elucidated the complex structures formed upon addition of anion to the croconamides, confirming the order of association constants towards the halogen anions. The use of croconamides as organocatalysts in a proof-of-concept study is demonstrated in the formation of THP ethers. In addition to this, construction of a Hammet plot further elucidates the mechanism in action on formation of THP ethers.

In this contribution we show that the newly discovered 6 + 6 biotin-formaldehyde macrocycle Biotin[6]uril binds a variety of anionic guest molecules in water. We discuss how and why the anions are bound based on data obtained using NMR spectroscopy, mass spectrometry, isothermal titration calorimetry (ITC), computational calculations and single crystal X-ray crystallography.

The discovery of receptors using templated synthesis enables the selection of strong receptors from complex mixtures. In this contribution we describe a study of the condensation of d-biotin and formaldehyde in acidic water. We have discovered that halide anions template the formation of a single isomer of a 6 + 6 macrocycle. The macrocycle (biotin[6]uril) is water-soluble, chiral and binds halide anions (iodide, bromide and chloride) with selectivity for iodide in water, and it can be isolated on a gram scale in a one-pot reaction in 63% yield.

In this paper we describe a new class of antiaromatic planar cyclooctatetraenes: the diazadioxa[8]circulenes. The synthesis was achieved by means of a new acid-mediated oxidative dimerization of 3,6-dihydroxycarbazoles to yield the diazadioxa[8]circulenes in high yields. The synthetic protocol appears to be general, and is a one-pot transformation in which two CC bonds and two CO bonds are formed with the loss of two molecules of water. We also present a detailed characterization of the optical and electrochemical properties of this new class of stable planar cyclooctatetraenes. The properties of the diazadioxa[8]circulenes are compared with the properties of isoelectronic tetraoxa[8]circulenes and azatrioxa[8]circulenes. We discuss the antiaromatic nature of the planar central cyclooctatetraene moiety. The antiaromatic nature of the planar cyclooctatetraenes was studied by using computational methods (NICS calculations), and these calculations reveal that the central eight-membered ring has antiaromatic character.

The complexation of oxacillin to three generations of 1-(4-carbomethoxypyrrolidone)-terminated PAMAM dendrimers was studied with NMR in CD3OD and CDCl3. The stochiometries, which were determined from Job plots, were found to be both solvent- and generation-dependent. The dissociation constants (Kd) and Gibbs energies for complexation of oxacillin into the 1-(4-carbomethoxypyrrolidone)-terminated PAMAM dendrimer hosts were determined by (1)H NMR titrations and showed weaker binding of oxacillin upon increasing the size (generation) of the dendrimer.