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The aim of this thesis has been to provide the ground work for the electrochemical sensing of analytes in polymer-functionalized microchannels via gold-coated microfabricated microchannel electrodes and for the in-situ study of the adsorption of particles in polymer brushes through molecular dynamics simulations. Both these objectives encompass polymer systems that are out of equilibrium and reveal how particles interact with these polymers. The aim was accomplished via the successful fabrication of in-channel gold-coated electrodes within a microfluidic device. To these gold-coated electrodes a redox-active polymer, poly(ferrocenylsilane) (PFS), was attached, via which sodium ascorbate could be sensed. To further understand the effect of particles in polymer systems, molecular dynamics (MD) simulations were performed on the insertion of particles of various size, shape and orientation, into a polymer brush. The force-distance curves were successfully modelled by two different models, one using scaling arguments and one aided through MD. Furthermore, the effect of shaking the wall, to which the polymer brushes are attached, on the penetration depth of particles into the brush was simulated, to approximate biological microsystems. From these could be concluded that if the brush is oscillated at its resonance frequency at a complementary resonance amplitude, the increase in penetration depth is at its maximum.

In this thesis we tackle the synthesis, characterization and function of novel organometallic polyanions, polycations, and their corresponding hydrogels and explore the use of these redox-responsive water-soluble or water-swellable materials in applications where either their charge or their redox activity leads to new opportunities, such as in metal nanoparticle fabrication and transfection. In addition, crown ether-functionalized aromatic polymers and organometallic polymers will be explored for ion separation and – sensing.

In this Thesis, the development and the characterization of polymeric films with the ultimate goal of switching the properties of functionalized microchannel surfaces is presented. The coatings were mainly based on two types of stimulus responsive polymers, temperature responsive poly(N-isopropylacrylamide)(PNIPAM) and redox-responsive poly(ferrocenylsilane) (PFS). These polymers allow one to control wettability, adhesion force, and friction which are important variables for preparing designer microchannels. Surface switching was primarily studied by colloid probe AFM. The motivation for the choice of PNIPAM and PFS is rationalized by their responsiveness and by the opportunities for anchoring these polymers to solid substrates, allowing one to functionalize the inner walls of microfluidic devices and tune the surface properties of these walls to control flow. As a proof of concept, we present a study of PFS functionalized channels for switchable delay valves.

Organic thin layers, especially self-assembled monolayers (SAMs), on well-defined solid surfaces have attracted tremendous attention owing to their interesting physical and chemical behavior as well as potential applications. The aim of this PhD thesis was to study the structural properties, electronic properties and dynamical process of SAMs. The objective was achieved by using scanning probe microscopy techniques, like time-resolved scanning tunneling microscopy (TR STM) and electrochemical atomic force microscopy (EC-AFM), with high spatial resolution and time resolution. Employing a current-voltage (I-V) converter with a large bandwidth, current-time spectroscopy, while the feedback loop disabled, can be recorded (hereafter referred as I-t traces). In this way, a high temporal resolution for STM can be achieved. This makes STM a versatile tool for the characterization of the structure, electronic properties and dynamics of SAMs. Recently developed peak force tapping AFM enables one to measure soft biological samples with high special resolution and minimal damage for the sample. With the combination of peak force tapping mode in EC-AFM, morphological responsiveness of redox-active metalloprotein azurin molecular layers were investigated.

In this Thesis, we aimed at developing novel tailored architectures and exploring rationally designed systems as redox active platforms for specific functions with organometallic polymer poly(ferrocenylsilane)s (PFSs). The preparation and characterization of various PFSs are described, including virtually unexplored structures. PFSs are a fascinating class of processable materials with redox characteristics suitable for the modification of surfaces and electrodes and have significant potential in the electrochemical detection of biological analytes. First we embarked on the quest to enhance the range of applications of surface bound PFS for sensing. To this end, we developed new strategies to immobilize the polymer on electrodes by electrografting, layer-by-layer deposition in combination with covalent coupling and simple grafting to methods. These redox-active interfaces displayed excellent sensing abilities towards ascorbic acid and hydrogen peroxide. As we primarily aimed at biomedical applications, we mainly focused on water soluble PFS systems, including polyionic liquids and hydrogels. Inherent to the redox responsive behavior, PFS hydrogels have the ability to reduce metal ions that exhibit oxidation potentials exceeding the value typical for ferrocene. We tackled the question of making various PFS hydrogel structures, which could be swollen by electrolytes including the metal ions of interest. In the reduction process without the use of any external reducing agents, metal nanoparticles form upon exposing the salt solutions to the PFS hydrogel. These particles can be further used in sensing, in catalysis and for antimicrobial surfaces. This PFS hydrogel platform that we call “metal nanoparticle foundry” was established in bulk gels and gel films, and some applications were illustrated.

With increasing life expectancy, there is an constant demand for finding solutions to restore damaged or diseased tissues and organs. Regenerative medicine holds the promise to create continuous body-part replacements through the combination of cells, biological factors, and synthetic scaffolds. However, a better control over cell-material interactions needs to be achieved to fabricate better performing and long-lasting supports for tissue engineering (TE). In the human body chemical and physical gradients regulate cell migration and differentiation. It is thus crucial to control these processes in 3D artificial scaffolds used in regenerative medicine. In order to accomplish this, the modification of biomaterials’ interfaces represent a potentially successful approach. This includes the fabrication of synthetic extra-cellular matrices (ECMs) presenting interfacial gradients which can regulate the behavior of adhering cells. Inspired by these approaches I fabricated chemical gradients on polymer substrates in order to determine cell response on both 2D and 3D supports. A specific focus is placed on polymer brush coatings with controllable properties (adhesion, flexibility, bioactivity) synthesized by surface-initiated atom transfer radical polymerization (SI-ATRP). By this method poly(N-isopropyl acrylamide) (PNIPAM) and functionalizable poly(oligo(ethylene glycol) methacrylate (POEGMA) brushes were “grafted-from” 2D and 3D poly(e-caprolactone) (PCL) supports. These thermoresponsive PNIPAM layers were applied to thermally control cellular adhesion while POEGMA-coated supports were used to vary the bioactivity of the coating via conjugated with fibronectin (FN) and growth factors. The peculiar physical properties of POEGMA brushes such as wettability and high functionality were exploited to obtain multi-dimensional surface gradients of (bio)chemical signals for spatially controlling cell behavior.

In this thesis, hybrid methods for nanoscale characterization of heterogeneous thin polymer films were discussed. Essentially two ellipsometry based hybrid methods were established or further developed, respectively, namely electrochemical imaging ellipsometry (EC-IE) and scanning near field ellipsometry microscopy (SNEM). Ellipsometry was combined with electrochemical methods for the visualization of redox driven dynamic changes in thin polymer films. In particular, the redox responsive behaviour of an oligoethylene sulfide end-functionalized poly(ferrocenyldimethylsilane) (ES-PFS) film was investigated with this hybrid method against a passive (non-redoxactive) 11-mercapto-1- undecanol (MCU) layer. The thickness change of the PFS layer upon oxidation and the reduction was observed in situ in real time with EC-IE. This hybrid method provides vertical resolution at the sub nanometer scale while its lateral resolution is limited to the wavelength of the light source (λ=633 nm). In contrast, SNEM reveals lateral resolution below the diffraction limit of the light. The emphasis of the thesis was devoted to SNEM, including the introduction of the instrument, experimental case studies to enlighten its contrast formation and the optimization of the method. SNEM enables optical contrast imaging of thin transparent polymer films at the nanoscale due to the combination of the spatial tip-sample positioning capability of the atomic force microscopy (AFM) together with the high sensitivity of ellipsometry.

The aim of this thesis was the development of stimulus responsive polymer brush structures as micropore switches for molecular screening. This was achieved by grafting pH responsive poly(methacrylic acid) (PMAA) brushes from nanoporous platforms that were then integrated in functional assays for membrane proteins. Several properties of the smart PMAA brush contributed to the functionality of such protein assays. Controlled transport of ions and molecules through nanopores, support of pore spanning artificial lipid bilayers and positioning of membrane proteins over the pores were achieved with the explored PMAA brush functionalized platforms.

This thesis describes the preparation and characterization of addressable responsive polymer structures and their versatile applications. Stimuli responsive polymer chains including temperature responsive poly(N-isopropylacrylamide), PNIPAM, pH responsive poly(methacrylic acid), PMAA and redox responsive poly(ferrocenylsilane) PFS can be assembled into various functional polymer architectures such as polymer grafts on surfaces by “grafting to” and “grafting from” approaches and polymer networks in bulk including macroscopic hydrogels and microgels/nanogels systems.

The work described in this Thesis aimed at a better understanding of the structure-property relationships of supramolecular assemblies with a specific focus on hydrogen-bond dimers and polymers. The hydrogen-bond strength of (supra)molecular complexes in different solvents is usually determined by measuring the concentration dependent transition of dimers to monomers in the solvent of interest, e.g. with isothermal titration calorimetry (ITC) or nuclear magnetic resonance spectroscopy (NMR). However, these ensemble averaging methods may hide interesting effects, such as unresolved transition states or the influence of molecular aggregates in solution. They are also not applicable for complexes formed at low concentrations. Since supramolecular hydrogen-bonded systems are nowadays used and further developed as building blocks e.g. for self-healing polymers and molecular motors, single molecule measurements can provide new molecular level insight to support this development for future applications. Furthermore single molecule investigations are interesting from a fundamental point of view due to the disparity of theoretical calculations and bulk measurements of equilibrium dimerization constants Kdim observed in several of these systems. The experimental work described in this Thesis covers the synthesis and characterization of self-assembling supramolecular hydrogen-bonded arrays in the bulk as well as at surfaces. In particular atomic force microscopy-based single molecule force spectroscopy (AFM-SMFS) was used to investigate the energy landscape of the hydrogen-bonds in ureidopyrimidinone (UPy) and urea-aminotriazine (UAT) dimers and polymers in different solvents (2-propanol, 1-nonanol and hexadecane). Exploiting the Kramers-Bell-Evans approach, this technique directly yields equilibrium dimerization constants Kdim based on the measured bond strength values at different bond loading rates (stretching rates) of individual molecules, provided that an estimate for the on rate of the complex formation or the diffusive relaxation time is known. The formation and bond failure of supramolecular polymers of the two self-complementary quadruple hydrogen-bonded arrays is successfully studied as well. The rupture force observed as a function of the number of linkers N is in quantitative agreement with the theory on uncooperative bond rupture for supramolecular linkages switched in a series, which provides a new approach to determine the relevant kinetic parameters from SMFS measurements at one single loading rate.

The research described in this Thesis comprises the development of Scanning Thermal Lithography (SThL) as an alternative approach for the spatially controlled, highly localized thermal chemical surface modification of polymer films for the development of e.g. (bio)sensors. In the Thesis, the range of thermal transport from heated AFM probes in contact with polymer surfaces is assessed. Proximity effects of thermally conductive substrates for supported thin polymer films on the calibrated probe tip-sample interface temperature for heated AFM probes are elaborated. Having established the basic needs for the development of SThL in terms of heatable AFM probes, the well established polystyrene-block-poly(tert-butyl acrylate) (PS-b-PtBA) polymer film platform was explored for utilization in thermochemical surface activation reactions, starting with Reactive Imprint Lithography (RIL) at the macroscopic length scale. RIL comprises the topographical patterning and the simultaneous thermal deprotection of the tert-butyl ester protected carboxylic acid groups in the PtBA block. The successful thermal chemical functionalization followed by the wet chemical surface derivatization with e.g. poly(ethylene glycol), was followed by the introduction of SThL on the PS-b-PtBA film platforms to enable thermal chemical surface functionalization at the sub-micrometer length scale. Disadvantage of the block copolymer film platform were the observed thermomechanical surface deformations, exceeding 400 nm in diameter, after SThL. Therefore crosslinked tert-butyl (meth)acrylate polymer films were prepared and their thermal decomposition mechanism was analyzed in detail followed by their utilization in SThL. Overall SThL is shown to be a promising nanotechnology tool for the thermal chemical surface modification with sub 50 nm spatial resolution.

Quantum dots, QDs, receive growing attention from many research disciplines owing to their advantages as fluorescent probes including their nanoscale size (similar to biomolecules), high quantum yield and molar extinction coefficients, versatility in surface modification, broad excitation spectra (for multicolor imaging) and narrow band emission and tunable optical properties. Fabricating QD/polymer hybrid nanostructures enables realization of many potential applications as optoelectronic devices, biological sensors, and photonic structures because encaging QDs within polymer matrices not only enables the control over optical and spectroscopic properties of QDs but also introduces a strong resistance to chemical and photodegradation. The research described in this thesis aims at synthesis and characterization of CdSe/ZnS core/shell QDs, synthesis and characterization of temperature-responsive polymer matrices made of poly(N-isopropylacryl amide), PNIPAM, as carriers of QDs, and fabrication of QD/PNIPAM assemblies with potential applications as sensing devices to be used in bio-nanotechnology.

The main goal pursued in this thesis is to investigate the role of organometallic polymers in bottom-up and top-down nanofabrication techniques to provide patterned platforms. Poly(ferrocenylsilane)s (PFSs) were explored for their use in top-down fabrication since they show a high etch resistance to reactive ion etching (RIE). The PFS polymers synthesized were used as resists in top-down lithographic applications on the micro- and nanometer scales. Phase separation in block copolymers was used to create bottom-up patterns on a nanometer scale. Surface-initiated polymerization (SIP) was performed for the preparation of polymer brush patterns for use in biological applications. Different lithography techniques such as nanoimprint lithography (NIL), UV-nanoimprint lithography (UV-NIL) and nanosphere lithography (NSL) were employed to fabricate patterns of PFS. The patterns fabricated were further utilized to create structures on various polymer and silicon surfaces at different lengthscales. In addition, nanostructured polymer brushes were grafted from a patterned initiator obtained by the step-and-flash imprint lithography (SFIL) process. Block copolymer self-assembly was also used to generate nanoperiodic PFS patterns. Symmetry, pattern quality and correlation as a function of the primary structure of polystyrene-block-poly(ferrocenyldimethylsilane) (PS-b-PFS) is discussed.

This thesis demonstrates the power of chemical surface engineering in the design and fabrication of functional hybrid materials made of Quantum Dots. The small size of the QDs, in the range of 1 to 10 nm, and related stability in solution, require a careful consideration of a proper surface chemistry for the ligand shell. By a judicious choice of the coating one can remarkably influence the physicochemical and photophysical properties of the semiconductor nanocrystals as well as design and engineer new generations of advanced nanoscale materials. This work describes in detail the synthetic approaches to chemical surface functionalization of QDs with electroactive ligands, including ferrocenyl thiols and poly(ferrocenylsilanes), and with β-cyclodextrin (β-CD) ligands suitable for supramolecular host-guest assembly. These functional ligands are shown to be important components in the engineering of new types of QD hybrid materials. The influence of the electroactive ligands on the optical properties of QDs was investigated by spectroscopic and electrochemical methods. These investigations gave an important insight into the quenching mechanisms of QDs by ferrocene and to the fundamental electron transfer processes in hybrid materials composed of QDs and electro-active ligands. Additionally, ferrocene groups located on the QD surface were shown to be able to take part in host-guest complexation reactions with β-cyclodextrin in solution. This ability was useful in the phase transfer of hydrophobic nanoparticles between solvents of markedly different polarities. The complexation ability of β-CD-functionalized QDs and adamantyl dendrimers was exploited for the preparation of supramolecular multilayer structures on surfaces. Surface bound QDs were shown to be able to transduce optically the binding events to the β-CD cavity, a proof-of-principle for a sensor design. This thesis demonstrates that both FRET and ET can be used as the transduction mechanisms. Thus, proper surface design and engineering of QDs gives unique opportunities to obtain the new class of hybrid materials using numerous functionalization approaches and surface chemistries.

The research described in this Thesis is centered around the utilization of block copolymer (BCP) vesicles formed by the self-organization of amphiphilic block copolymers in solvents as nanocontainers to encapsulate enzymes and substrates, and the investigation of the influence of the container’s dimensions on the catalytic activity of the enzymes. In the Thesis, the phase behavior of PS-b-PAA in solution is described. The effect of preparation conditions on the size and morphology of the BCP aggregates is addressed in detail. The stiffness of the membranes of PS-b-PAA vesicles is assessed using an AFM based nano-indentation method. The relation between the rigidity and the thickness of the membranes was elucidated. The enzymatic reactions in nanocontainers and the confinement effect on the catalytic activity of different enzymes were subsequently investigated using two different enzyme-substrate systems. The kinetic parameters for the enzymatic reactions were obtained for the unrestricted reaction in solution as well as for the reaction confined to the interior of polymeric vesicles with different sizes, and the dependence of the rate constants of the reaction on the size of the containers was studied. The morphology and size of PS-b-PAA aggregates prepared at different temperatures were studied. The existence of a phase transition from vesicles to micelles as a result of temperature change was confirmed. A change in temperature was then utilized as an external stimulus to trigger the release and encapsulation of enzyme and substrates, initiating their reaction.

The aim of the work described in this Thesis was to develop new fabrication techniques based on surface-initiated controlled polymerization (SIP) for the preparation of functional polymeric platforms across the lengthscales. Several synthetic processes based on controlled radical SIP were employed for the preparation of polymer brush platforms which presented tunable characteristics and, in some instances, a stimulus-responsive behavior. The SIP methods employed were furthermore coupled with atomic force microscopy (AFM)-assisted nanolithographic approaches in order to accomplish the preparation of polymer grafts constituted by a limited number of macromolecules grown on pre-determined positions on surfaces.

The understanding of biointerfaces in contact with seawater is crucially important in tackling the problems of marine biofouling. Such biointerfaces involve the bioadhesives used by marine organisms to attach temporary or permanently to the surfaces immersed in water. The aim of this Thesis is to address a particular problem, i.e. barnacle adhesion, to the biointerface and the corresponding fouling process. We try to understand the first steps of the fouling process of this species, and help to set up design criteria for surfaces to suppress, or prevent, corresponding biofouling. The focus in this Thesis is on AFM-based nanoscale characterization of marine bio-interfaces created by barnacle cyprid larva during surface exploration. The application of AFM has the advantages of first visualizing the fouling interface (also in situ), and to measure its nano-scale properties featuring bioadhesives and adhesives in native environments. The morphology and nanomechanical properties of the cyprid temporary adhesive - “footprints” deposited on the surfaces were extensively studied. In addition, bio-interfaces created on surfaces with different wettabilities were used to investigate the settlement behavior of cyprid larvae in laboratory settlement assays and marine field tests. In-depth investigations of barnacle adhesive properties were performed by in situ monitoring of the enzymatic proteolysis degradation of footprint and the in situ curing process of cyprid permanent cement.

This thesis describes the synthesis and electrostatic assembly of organometallic poly(ferrocenylsilane) (PFS) strong polyelectrolytes. The distinctive structural features of poly(ferrocenylsilanes) come from the silicon and iron atoms in the main chain. The presence of redox-active ferrocene units in the polymer backbone provides unique redox-responsive properties to PFS. The charged nature and redox-responsiveness of these organometallic polyelectrolytes makes them particularly useful in the electrostatic self-assembly process for the fabrication of novel functional supramolecular nanostructures. A major part of the research described in the thesis (Chapter 4-6) is focused on the electrostatic layer-by-layer assembly featuring poly(ferrocenylsilane) polyelectrolytes.

The aim of the present Thesis is to enhance characterization and surface engineering approaches to test and control physico-chemical changes on modified hydrophobic (LDPE and PDMS) and stimulus-responsive (PFS) polymers across different length scales. [Here LDPE denotes low density polyethylene, PDMS stands for poly(dimethylsiloxane), and PFS for poly (ferrocenyldimethylsilanes)]. Efforts have been made to design and engineer desired surface properties of selected polymers and to characterize the chemical composition, electrokinetic and mechanical properties by various experimental techniques from the nano to the meso scale. Furthermore, a comparison of these techniques has been carried out in order to understand the aforementioned issues.

The work described in this thesis aimed at gaining a better understanding of factors involved in directed self-assembly of block copolymer microdomains. For many possible applications of block copolymers, such as high density data storage, the positional control of microdomains is crucial. Understanding the mechanisms governing the ordering in phase separated block copolymers is therefore fundamental for designing usable systems. In this study, organicorganometallic block copolymers were used, in which the organometallic block was poly(ferrocenylsilane) (PFS). The presence of iron in the backbone of these polymers imparts properties such as etch resistance or catalytic activity to the polymers. Therefore, PFS containing block copolymers can directly be used as nanolithographic templates or for the fabrication of a catalytic platform of nanosized domains. Two different approaches were explored and are described in this thesis. The first approach involved the study of the effect of chemical and topographical modifications of a substrate on the morphology of one particular type of diblock copolymer. The second method involved the study of polymersubstrate interactions in diblock copolymers with different chemistry.

The aim of the work described in this Thesis was to develop the necessary platform for quantitative nanotribology by atomic force microscopy at relevant length and time scales and thereby to contribute to bridge the gap between complementary nano- and microtribology. The primary focus was centered on the development of a nanotribology platform that included reliable quantification procedures for friction force measurements and the extension of the range of scanning velocities to 2 mm/s with full environmental control, as well as on the investigation of relevant tribological phenomena on the nanometer scale. The effects of nanostructure, environment and velocity on friction were revealed for different types of samples, ranging from ceramics to polymers, that are important for various types of applications, e.g. advanced coatings.

A brief introduction to the topics that are relevant for this thesis is presented, Attention was given to various colloidal crystallization methods, such as colloidal crystallization on flat, chemically and lithographically modified substrates as well as under applied external fields. Special emphasis was placed on reviewing the current status in the area of colloidal crystallization on topologically patterned substrates.

Molecular level visualization, sensing (by force), manipulation, and control of supramolecular assemblies and polymeric materials have been explored in this Thesis on the nanoscale using self-assembled monolayers (SAMs) and atomic force microscopy (AFM)-based platforms.

This thesis presents developments in the field of nanoscale probing of polymers. New experimental methods based on single molecule fluorescence detection were developed and applied to polymer studies. Localization of, and communication with individual fluorescent molecules embedded in a glassy polymer or immersed in a polymer melt have been realized by using various, optical techniques e.g. Scanning Confocal Microscopy and Wide-Field Microscopy. Location of single molecules as well as their orientation, emission spectra or fluorescence lifetime have been followed in time. This allowed us to perform dynamical studies in the time domain. Since full distributions of single molecule behavior (e.g. rotational diffusion constants, fluorescence lifetimes) were obtained, systems with heterogeneous dynamics could be clearly identified and sub-ensembles, which could be characterized with different dynamic properties, were separated and investigated. Besides polymer probing studies, it was also shown how relatively simple structures can be prepared and used to engineer the emission properties of single molecules. In particular, the fluorescence emission of single molecules in thin polymer films and in electrospun polymer fibers was shown to depend on the size of the structures.

This thesis is the result of a project initiated by the Dutch Polymer Institute (DPI). The general theme involves "molecular characterization and morphology development in polypropylene obtained by metallocene polymerization". Throughout this investigation, the general theme was shaped and filled in by a variety of studies on structure-property relationships in polypropylene.

This thesis is concerned with new approaches to measuring the interfacial mechanical properties of amorphous polymers on the micrometer and nanometer scale. In order to achieve this goal, several innovative instrumental techniques were developed during this work. Polymer adhesion was characterized on the mesoscale with a home-built, highly automated adhesion-testing device. Nanoscale characterization of polymer surfaces was investigated with a customized atomic force microscope. Chapter One gives a general introduction to polymer adhesion and outlines the scope and nature of this thesis. Chapter Two provides an overview of some of the most important concepts relevant to this thesis. Surface energy and polymer mechanical properties are introduced. These properties are then linked through contact mechanics theory. The Johnson-Kendall Roberts (JKR) and Hertizan contact mechanics theories for elastic solids are discussed and compared. Furthermore, some of the limitations of these theories are discussed, with particular emphasis placed on the effects of viscoelasticity. Chapter Three introduces an adhesion-testing device built as a part of this research project. This device is shown to be capable of providing an estimate of the work of adhesion between two solid substrates. The work of adhesion was determined for a polydimethylsiloxane (PDMS) lens and several end-functionalized thiol substrates and was shown to depend on the end-functionality of the monolayer. The adhesive performance measured by this device of two pressure sensitive adhesives is shown to compare favorably with conventional adhesion tests. Lastly, the presence of a capillary neck between the sample substrates is shown to influence the shape of the adhesion curves obtained by this device. Using the instrumentation described in the previous chapter, the dynamic adhesive characteristics of polydimethylsiloxane is further explored in Chapter Four. The adhesion hysteresis of PDMS is shown to be a complicated function of the substrate surface roughness and hydrophobicity, ambient humidity, and the time of interfacial contact. The dynamic adhesive performance of PDMS is postulated to result from the formation of favorable interfacial bonds, both mechanical and physicochemical in nature. From Chapter Five onwards, the focus of the thesis is shifted towards interfacial mechanical properties of polymers on the nanometer scale. In this chapter, a mechanism for the surface modification of glassy polymers is offered. A semiquantitative analysis based on the JKR theory shows that stresses exerted by the AFM tip can easily exceed the critical yield strength of the polymer. A mechanism is offered to explain the nanometer scale deformation of a glassy polymer under repeated scanning by an AFM tip. Chapter Six explores the influence of instrumental parameters on tapping-mode AFM images of phase-separated polystyrene-b-polyisoprene-b-polystyrene thin films. The discussion is begun with a simulation of a dynamic force curves on both of the homopolymers. Because polyisoprene is very compliant at room temperature compared to polystyrene, less damping of the cantilever occurs as the tip penetrates further into the material. Both height and phase-mode contrast are shown to vary locally depending on excitation frequency and averaged damping of the cantilever. The contrast variations are reconciled by considering the local interactions experienced by the tip. The dynamic adhesional character of polydimethylsiloxane is described in Chapter Seven. Two model crosslinked networks were characterized by bulk rheology, which revealed that the network with added free chains was more viscoelastic than the polymer without added free chains. Custom software and hardware were developed to process AFM force curve data in real time. The adhesion hysteresis of AFM force curve experiments is shown to increase on two time scales for the sample with added free chains. At longer times, the increase in adherence is postulated to result from viscoelastic creep. At shorter times, the increase of the adhesion hysteresis is attributed to increased energy dissipation that occurs at the receding crack tip due to viscoelastic effects. Furthermore, the effect of the adherence is shown to increase as a function of the maximum applied load. Finally, the adherence is shown to depend on the molecular weight of the added free chains. No such effects were observed for the sample without added free chains. The results are discussed in terms of the viscoelastic response of the polymer under the applied stress of the AFM tip. Using the instrumentation developed in the previous chapter, the adherence of poly(2-ethyl hexyl methacrylate) was investigated over a range of temperatures and strain rates in Chapter Eight. In AFM force curve experiments, the slope of adherence-indentation curves is shown to scale with the storage modulus, except near the glass transition temperature where a strong peak is observed. The creep compliance of the material could be directly visualized at different temperatures by allowing the tip to interact for a period of time while recording the cantilever deflection. The increase of adherence is reconciled in terms of an increase in the interfacial contact area due to viscoelastic deformation by the AFM tip. In summary, this work has examined the interfacial mechanical properties of polymer interfaces on the micrometer and nanometer scale. On both length scales, the adherence is believed to increase due to an enhancement of the interfacial contact area, the time scale and magnitude of which is determined by the viscoelastic properties of the polymer. Even on the nanometer scale, the interface appeared to behave in accordance with bulk mechanical properties and predictions grounded in contemporary contact mechanics theory of viscoelastic solids. However, truly quantitative confirmation of the theoretical predictions will remain elusive on both length scales until a method is developed in which the true interfacial contact area can be measured.

The work described in this thesis concerns the surface modification of materials by thin film deposition in a plasma reactor. In particular, thin polymeric films bearing amine functionalities were synthesized by plasma polymerization of amino group containing monomers. In addition to the synthesis, attention was directed towards the characterization of these films, and the tailoring of their surface properties on a molecular level. Finally, the amino groups introduced by plasma polymerization were used for the subsequent immobilization of graft polymers and biomolecules.

Surfaces in supramolecular and polymeric systems were characterized by scanning force microscopy (SFM) using probe tips functionalized with self-assembled monolayers (SAMs). This approach allows one to control the forces between tip and surface by immobilizing suitable molecules, which expose selected functional groups, onto gold-coated probes. The objective of this Thesis work was the extension of SFM with SAM-functionalized probes (so-called "chemical force microscopy", CFM) to technologically relevant surfacetreated polymers and elastomers with the ultimate aim of laterally resolved detection of functional group distributions on a sub-100 nm level. In measurements of interaction forces between a few or even individual molecules in supramolecular systems the transition from studying continuum to studying non-continuum properties was also attempted. In situ measurements of reaction kinetics using "inverted CFM" on a scale of 10 - 100 molecules were achieved. Furthermore, interactions between ensembles of functional groups and individual molecules were studied and provided fundamental insight into functional group distributions on polymer surfaces as well as rupture forces of individual host-guest complexes.