A firm knowledge about the interaction between the metal surface and adsorbed molecules is imperative for formulating procedures to synthesize nanoparticles (NPs) with predetermined shape and size. The ligand‐metal interaction during NP formation can be mimicked on an electrode surface by electrosorbing ligand molecules on a charged metal surface. Electrochemical methods can provide an ideal platform to study the adsorption behaviour of molecules at the solid‐liquid interface. In addition to classical electrochemical techniques, the combination of spectroscopy with electrochemical methods amplifies mechanistic insights about the surface adsorption processes. The adsorption behaviour of pyridine and one of its derivatives, 4‐dimethylamino pyridine (DMAP) have been well studied due to their potential application in nanoparticle synthesis. However, prior to this work, there has been very limited and conflicting literature available about the adsorption of of pyridine derivatives analogous to DMAP. Among the pyridine derivatives that were studied, some reports indicate that, other than DMAP, only 4‐methoxy pyridine (MOP) can stabilize gold nanoparticles. However, very little is known about the possible differences in the adsorption energy and general behaviour of MOP compared to DMAP. Resolving this knowledge gap is imperative to resolving the conflicting information about pyridine‐based stabilizers for metal nanoparticle applications. The adsorption behaviour of MOP on different crystallographic Au surfaces as a function of pH and surface potential has been investigated in this project. These studied were carried out using classical electrochemical methods including chronocoulometry and differential capacity, as well as modern spectroscopic techniques like Surface Enhanced Infrared Absorption Spectroscopy (SEIRAS). The thermodynamic parameters obtained from electrochemical data shows that adsorption features of MOP is similar to that of DMAP. However, there is a significant difference in the adsorption strength of MOP and DMAP at positive potentials. The SEIRAS data provides much more detailed information about the potential depended orientation of MOP on polycrystalline Au. Cumulative analysis of electrochemical and spectroscopic data provides strong evidence that MOP can stabilize Au(111) facets over wide pH ranges. Moreover, this work provides convincing evidence that the basic nature of substituted pyridine alters the metal to ligand adsorption strength.

京都大学 / 新制・課程博士 / 博士(工学) / 甲第23913号 / 工博第5000号 / 新制||工||1780(附属図書館) / 京都大学大学院工学研究科物質エネルギー化学専攻 / (主査)教授 作花 哲夫, 教授 安部 武志, 教授 阿部 竜 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM

Hardware Security Modules (HSMs) are embedded systems that provide a physically secure data storage and handling environment. This master thesis evaluates an HSM method incorporating cryptographic key generation, key management, and tamper protection. The HSM concept involves a sensing mesh structured Physical Unclonable Function (PUF), where the cryptographic key is derived from the sum of cross-sectional area capacitance between conductors on adjacent layers of a flex PCB forming a grid. This sensing mesh PUF that stores a digital fingerprint in its microstructure is used to enclose an internal system extracting and managing the keys. This ensures that accessing the internal structure is unmanageable without modifying the enclosure. Since the cryptographic key is derived from the intrinsic properties within the sensing mesh, modifying it will change its intrinsic properties and change the cryptographic key and make it unusable. The Master thesis contains PCB design and development of a prototype of the PUF system and an associated capacitance measurement system, which can handle and extract unique keys from each copy of the PUFs. A hardware assembling, experimenting, and evaluation procedure were performed regarding the robustness of the PUF and its susceptibility to environmental impacts such as temperature changes, invasive attacks, and agitation. Additionally, an performance evaluation is made by estimating a set of quality factors often associated with PUFs, such as uniqueness, reliability, uniformity, and bit-aliasing on the extracted cryptographic keys. The cryptographic keys provide good reliability in stable conditions for each PUF copy of the population. The cryptographic keys also provide gooduniqueness, uniformity, and bit-aliasing estimations with the quality factors. Moreover, an invasive attack experiment indicates that the PUF enclosure prototype provides tamper detection possibilities together with distinct structure modifications when an intrusion attempt is performed. As stated in theory, PUFs are sensitive to environmental changes, which is also observable in the results when the PUF enclosure prototype is exposed to various environmental conditions. / <p>Examensarbetet är utfört vid Institutionen för teknik och naturvetenskap (ITN) vid Tekniska fakulteten, Linköpings universitet</p>