This project deals with the design, synthesis and evaluation of ink jet dyes to bind to inorganic oxide surfaces particularly that of aluminium oxide. Alumina is applied as a coating on ink jet paper for use in the high added value markets. Chapter 1 provides an overview on the ink jet printing industry but focusing mainly on printing on paper, ink development, papers required for printing, dyes, and absorption isotherms. ‘Simple’ azo dyes are considered in Chapter 2, and binding of these dyes to aluminium trihydroxide [A1(OH)₃] is examined. Synthetic routes to novel phosphonic acid azo dyes were developed. Iostherm studies demonstrated that phosphonic acid dyes bind much more strongly to A1(OH)₃ when compared against sulfonic, carboxylic, boronic, arsenic and phosphinic acid analogues. Dyes with different acidic functional groups were applied to different papers via ink jet method, and the prints were analysed for their light, ozone and humidity fastness properties. It was found that on changing the functional group of the dye, the humidity fastness was greatly affected. Other ink jet properties such as ozone and light fastness were more dependent on factors such paper type, and the percentage of inorganic oxide coated on the paper. In chapter 3, more complex phosphonic acid azo dyes were designed and synthesised to analyse both binding properties and ink jet properties. In chapter 4, absorption isotherms are reported on dyes in the presence of cyclodextrin to examine the effect of cyclodextrin on binding strength and surface coverage of the dyes. ROESY NMR studies were undertaken to provide conclusive evidence of the inclusion complex, dye-cyclodextrin and UV/vis and NMR studies were performed to determine the strength of these complexes.

The overall aims of this thesis were the preparation, using inkjet printing and robotics, of libraries of multi-component formulations for the design of new materials (pigment based inks, polymer blends and lipoplexes) applied to inkjet printer, cell binding and cell transfection, respectively. This was followed by their screening and the assessment of their suitability for its design, looking at which main variables (factors) and settings (range) influenced the properties of the formulations. A key component of the preparation of these libraries, was the application of a design of experimental methods, which directed the preparation of the formulations and allowed the development of mathematical models for material prediction and optimisation, as follows: (1). Formulations of pigment based inks, which were prepared and analysed for determination of which components provided a suitable viscosity for good jet performance and printing quality. Model development showed that diethyleneglycol was the main mixture factor that controlled viscosity, while voltage and pulse width were the main process factors that provided an increase of drop velocity and spread on substrate. (2). Formulations of polymer blends were assessed for cell binding. The best blends were poly(DL-lactide-co-glycolide) and chitosan. Rheological analysis showed that blends containing 50 % w/w of chitosan gave the highest values of viscosity and shear thinning behaviour, showing their loss moduli(G”) greater than their storage moduli (G’). (3). Lipoplexes are combinations of DNA and cationic lipids that are used to transfect cells. Formulation libraries of cationic lipids were prepared, with model development, showing that the ratios of cationic lipid/DNA and co-lipid/cationic lipid were the most important factors, and were inversely proportional to transfection.

Over the past twenty years there has been increasing interest in the surface topography of sheet steel. Four processes are currently in commercial use to texture the rollers used in the production of the sheet and have been the subject of many studies. The aim of this project was to research the combination of ink jet printing technology and chemical and/or electro-chemical machining as an alternative process for the texturing of rollers for sheet steel production. This has resulted in a new process, termed <I>ink-jet texturing. </I>Ink-jet texturing is a subtractive process where a printer is used to deposit an ink mask onto the surface of the roller. This is followed by a chemical or electrochemical machining process which etches those areas not masked to a depth of several micro-metres. Chemical and electro-chemical processes have both been investigated. During the course of the study four pairs of roller were treated for a commercial pilot rolling mill. Sheet samples produced by these rollers have been measured, analysed and discussed in the context of other technologies. The main challenges in the research concerned the accuracy and integrity of the ink mask, the reduction of waviness in the machined surfaces and the interaction between them. The thesis starts with a technological proof of concept using a chemical machining process. The chemical process was subsequently replaced by an electro-chemical one for reasons of speed, cost and environmental responsibility. The majority of the research was concentrated on the electro-chemical texturing (ECT) which culminated with the production of samples of rolled sheet for analysis. Issues of texturing time, cost, wear and reliability have also been investigated to enable the commercial viability to be assessed. Apparatus has been designed, constructed and tested for both chemical and electro-chemical texturing and the results appraised in the context of existing processes. Finally, the potential of the process to work in a commercial environment is examined. The ink jet method offers significant economic savings over competing technologies but real improvements would be required in the repeatability of both masking and machining operations.

Over the last decade the multilayer perceptron (MLP) artificial neural network (ANN) has been applied increasingly to nonlinear modelling problems in fields such as process control and machine vision. Nonlinear modelling is also a problem which has been studied extensively by statisticians for several decades, and in recent years several people have pointed out that standard MLP and statistical regression methods are in fact very closely related. This is a useful observation because MLP modelling has traditionally been a somewhat trial and error empirical process. Identifying the similarity between MLP and regression methods thus offers the possibility that the large body of existing statistical theory and practice may be used to improve our understanding and use of the MLP. This thesis adopts this approach to examining two important practical problems in MLP regression. These are: the use of robust estimators to improve the fit, particularly when the training data contains outliers, and prediction error estimation for MLP model complexity selection. The investigations into robust MLP regression discovered that only simple robust estimators are likely to be useful in most MLP regression problems. Though more sophisticated estimators have previously been suggested for this task, it is shown why these are in fact unsuited to this. Estimating prediction error is a particularly important problem in MLP regression. The investigations into estimating prediction error yielded a fast method for estimating prediction error by cross-validation and also examined its limitations. This method is particularly useful when the amount of training data is limited. The primary motivation for investigating these two issues was the desire to use the MLP to model a phenomenon known as curl in papermaking, and to use this model to improve the yield of a papercoating process. Only a limited amount of data was available for this task, and it was suspected that the data included several gross errors. Since these are general problems in MLP regression, the techniques devised here have wide applicability and importance.

Pigments are widely used materials in inkjet inks and their surface properties are an important factor in their performance. The aim of this project was to devise methodologies for covalently modifying the surfaces of pigments in order to modulate their properties. This was achieved by activating the surface of pigments with either gamma or plasma irradiation and then covalently grafting polymers onto their surfaces. The four pigments used were: Pigment red 122, Pigment blue 15:3, Pigment yellow 155 and Carbon black, which are already used in Kodak inks. It was demonstrated that dispersability in water or DMF could be greatly improved by grafting polymers onto pigments. After dispersion tests over two weeks, poly(<i>N,N-</i>dimethylacrylamide) was found to be the best polymer to graft onto pigments in order to improve pigment dispersability in water, while polystyrene allowed dispersion of pigments in DMF. Further modifications were attempted by copolymerisation, cross-liking and esterification reactions. The optimised pigments were analysed using filtration, UV/Vis measurement, contact angle and SEM to determine their particle sizes and properties. They were used in basic ink formations, printed onto paper and tested against light and ozone fading.

Modern papermaking methods and paper user requirements place severe pressure on the converter in terms of paper cut quality and quantity. The future trends indicate continued and increasing use-of paper and allied products, hence there is considerable advantage in securing a reliable and acceptable method for reducing paper from real to more usuable form. Paper waking and conversion methods are outlined. An attempt is made to illustrate the complexity of cut quality and to formulate some broad concept of the term. The local strain of paper subjected to tensile and shear loading is examined and a mechanism is put forward for the formation of dust and structural damage during and in association with cutting. Shear cutting is examined in some detail; the relevant literature summarised and a series of practical experiments are described which illustrate how wear occurs and its effect on the cutting process. Razor, liquid jet and laser methods are examined as alternative techniques. It is concluded that their use is restricted to special applications where particular characteristics can be utilized. The literature concerning abrasive wear and paper as a wear medium is reviewed. It is concluded that significant improvements to slitter life can be made by changes in material specification and basic system design. The techniques used in the work could readily be used design. The techniques used in the work could readily be used in further practical experiments to examine paper and tool surfaces continuously in the field.

An examination of worn paper slitting blades from various paper mills showed that the predominant wear mechanism is abrasion with fatigue damage as a minor factor. A laboratory wear rig was designed and constructed to simulate an industrial paper slitting machine and which incorporated an instrument designed to measure accurately the change in profile of slitter blades during wear. Blades manufactured from BS 970 535A99 steel were worn with and without additions of paper dust and it is shown conclusively that three-body abrasion by hard particles in paper dust is the principal wear mechanism. An analysis was developed to give open cut distance at the point of slitting as a function of wear. A critical open cut distance was found when shear slitting changed to tensile slitting and an unsatisfactory cut was obtained; the critical open cut distance for various grades of paper was determined. A mill trial was performed which supported the validity of open cut distance as a measure of useful life of blades. The results were analysed using conventional wear theory and a linear relation between volumetric wear and running distance was obtained. The wear resistance was assessed of blades coated by the following surface treatments: - boridising, carburising, cermet plating and plasma are spraying. A cermet plating comprising diamond particles dispersed in an electroless nickel matrix produced the best wear resistance. Comparisons of the coated blades with the conventional steel blades lead to conclusions about surface structure and properties required to give good wear resistance in paper slitting blades.

The primary aim of this thesis is to study existing CM methods and assess their practicability and performance in harsh real-world environments. The motivation for this work was a real industrial application - the development of a paper curl prediction system. Curl is an important paper quality parameter that can only be measured after production. The available data were sparse and were known to be corrupted by gross errors. Moreover, it was suspected that data noise was not constant over input space. Three approaches were identified as suitable for use in real-world applications: maximum likelihood (ML), the approximate Bayesian approach and the bootstrap technique. These methods were initially compared using a standard CM performance evaluation method, based on estimating the prediction interval coverage probability (PI CP). It was found that the PI CP metric can only gauge CM performance as an average over the input space. However, local CM performance is crucial because a CM must associate low confidence with high data noise/low data density regions and high confidence with low noise/high data density regions. Moreover, evaluating local performance could be used to gauge the input-dependency of the noise in the data. For this reason, a new CM evaluation technique was developed to study local CM performance. The new approach, called classification of local uncertainty estimates (CLUES), was then used for a new comparison study, this time in the light of local performance. Three main conclusions were reached: the noise in the curl data was found to have input-dependent variance, the approximate Bayesian approach outperformed the other two in most cases, and the bootstrap technique was found to be inferior to both ML and Bayesian methods for data sets of input-dependent data noise variance.

A series of magenta azo dyes for use in inkjet printers have been synthesised in order to study the effects of substituted arylhydrazide substituents on their light and ozone fastness. Large-scale syntheses were successfully adapted to the laboratory and arylhydrazides were coupled to an existing azo dye <i>via</i> a cyanuric chloride coupling reaction in good yield and purity. Improved methodologies were developed for the synthesis of a series <i>N</i>-methylhydrazides, <i>N,N</i>’-dimethylhydrazides and <i>N’</i>-isopropylhydrazides. <i>N</i>-methylhydrazides were synthesised by reaction of methylhydrazine with an appropriate acid chloride. <i>N.N’</i>-dimethylhydrazides were synthesised from <i>N</i>-methylhydrazides, avoiding the use of the carcinogenic dimethylhydrazine employed in previous syntheses. Synthesis was <i>via</i> a reductive amination strategy employing previously unreported <i>N</i>-methyl, <i>N</i>’-methylidene arylhydrazides, followed by reduction with sodium cyanoborohydride. <i>N</i>’-isopropylhydrazides were also prepared <i>via</i> reductive amination, following condensation of commercially available hydrazides with propanone, again followed by reduction with sodium borohydride. The newly synthesised dyes were tested at Avecia (Blackley) for light and ozone fastness according to standard protocols. The <i>N</i>-methylhydrazides series of dyes showed slightly improved ozone fastness, light fastness was essentially unchanged across the range of dyes. Solution ozonolysis experiments were carried out on simple dye systems, such as 1-phenylazo-2-napthol and 1-phenylazo-4-napthol. In order to study the effects of azo / hydrazone tautomerism, some of the “locked” tautomers of these compounds were synthesised by methylation of the appropriate functional group. The main intermediate formed was napthoquinone. Solution ozonolysis was also performed on some of the more complex hydrazide substituted dyes previously synthesised and the rates of ozonolysis determined.

Inkjet printing was used for the fabrication and optimization of polymer microarrays for high-throughput screening of small molecule polymorphisms. In particular, inkjet printing was used for polymer deposition in a microarray format and for the dispensing of small molecules in solution. Crystals formed on polymer spots were screened for recording of the polymorphism. Moreover, inkjet printing was used for performing high-throughput polymerization. In the <i>in situ</i> nL scale polymerization the homo and copolymers were fabricated directly in microarray format. Prepared polymer microarrays were screened to identify polymers suitable for mouse embryonic stem cell adhesion and growth. To advance cell patterning in various non-microarray formats the strategy based on preferential cell binding on collagen was applied. Collagen was dispensed by inkjet printing in patterns laid-down by a bitmap converter. The second strategy for advance cell patterning was based on a simple masking process. A laser printer was used to generate a non-binding surface on glass. This simple concept delivered excellent results. Finally, polymer microarray screening was used to develop a platform for human cornea epithelial cell transfer. In this case, 252 polymers (polyurethanes and polyacrylates) were screened in a culture of cells. A transfer experiment was performed to prove the ability of cells to migrate from the cultivation surface to the target surface. The best polymer was then used to construct a platform suitable for medical use.