The purpose of this research was to explore two ways of the application of chitosan, a biopolymer, for ink jet printing of textiles. 1) To apply chitosan as a post-treatment on the fabric ink jet printed with pigment based inks for the fixation of pigments on the fabric. 2) To incorporate chitosan as a binder in pigment based ink jet ink formulations. The incorporation of chitosan was carried out in two ways. 1) Direct addition of chitosan into the ink formulations containing surface modified pigments. 2) Preparation of chitosan encapsulated pigment nanoparticles using complex coacervation technique and using these nanoparticles for the formulation of ink jet ink. The degree of deacetylation (DD) was determined using FTIR spectroscopy. Various protocols proposed by researchers were used to determine the DD of chitosan samples used in the present study. The protocol proposed by Raut was found to be fairly accurate in determining the DD of chitosan samples. The molecular weight of chitosan was estimated using dilute solution viscometry method. The characterisation of the film forming ability of chitosan was evaluated using scanning electron microscopy (SEM). The colour strength (K/S), colour difference, colour characteristics and colour fastness to laundering and rubbing of ink jet printed fabrics post treated with chitosan were evaluated using standard methods. Post-treatment (pad-dry-cure method) of cotton fabric ink jet printed with pigment based inks revealed that chitosan could effectively fix the pigments on cotton compared to the commercial textile binders and the water-soluble derivative of chitosan. The chemical interaction between chitosan and cotton fabric was illustrated by FTIR-ATR analysis and through determination of carboxyl group content. The ink jet printed cotton fabric post treated with 3gpl chitosan (MW 156,156) maintained almost 86% of bacterial reduction against Klebsiella Pneumoniae even after 50 launderings. Inks containing chitosan were formulated and were found to be stable in terms of mean particle size and viscosity over a period of one month and for 4 freeze/thaw cycles. A magenta ink containing chitosan was selected for ink jet printing of cotton fabric. It was found that the DF was around 97% for magenta ink containing chitosan compared to around 53% fixation for magenta ink without chitosan on cotton fabric. Surface modified carbon black pigment with carboxylated (COO-) surface functionality was selected to prepare chitosan encapsulated pigment nanoparticles by complex coacervation technique. Chitosan encapsulated pigment nanoparticles with mean particle size diameter of 876 nm and 742 nm were formed when 5 ml of 0.1% w/v pigment was mixed with 2ml and 3ml of 0.1% w/v chitosan, respectively. However, no correlation was found between the particle size of the nanoparticles formed and the concentration of chitosan. The DF with ink containing chitosan encapsulated pigment nanoparticles was found to be around 98% while the blank ink with only surface modified carbon black pigment showed 44% fixation.

A numerical model has been developed to simulate the firing of an inkjet printhead. The model evaluates the heat generation and diffusion within the thin film structure, the phase change and vapor bubble growth in the ink, and the subsequent flow of ink from the orifice. The heat transfer is modeled numerically throughout the printhead's thin film structure and ink through an asymptotic integration algorithm. The bubble growth and fluid flow are coupled and modeled through conservation of momentum, conservation of energy, and state equations. The heat transfer model has been validated with simple theoretical solutions and ink drop weight and velocity have been compared to empirical data. To test the usefulness of the model as a design tool, parametric studies have been made which characterize pen performance as a function of several system parameters. The results show that although the model does not reflect every detail in the firing process, it is useful for predicting trends and investigating new design concepts. / Graduation date: 1997

Additive manufacturing processes, which utilize selective deposition of material rather than traditional subtractive methods, are very promising due to their ability to build complex, highly specific geometries in short periods of time. Three-dimensional direct inkjet printing is a relatively new additive process that promises to be more efficient, scalable, and financially feasible than others. Due to its novelty, however, numerous technical challenges remain to be overcome before it can attain widespread use. This thesis identifies those challenges and finds that material limitations are the most critical at this point. In the case of deposition of high viscosity polymers, for example, it is found that droplet formation is a limiting factor. Acoustic resonance jetting, a technology recently developed at Georgia Institute of Technology, may have the potential to address this limitation because it generates droplets using a physical mechanism different from those currently in use. This process focuses ultrasonic waves using cavity resonances to form a standing wave with high pressure gradients near the orifice of the nozzle, thereby ejecting droplets periodically. This thesis reports initial exploratory testing of this technologys performance with various material and process parameters. In addition, analytical and numerical analyses of the physical phenomena are presented. Results show that, while the pressures generated by the system are significant, energy losses due to viscous friction within the nozzle may prove to be prohibitive. This thesis identifies and begins evaluation of many of the process variables, providing a strong basis for continued investigation of this technology.

No description available.

No description available.

Thesis (M.S. in mechanical engineering)--Washington State University, May 2008. / Includes bibliographical references (p. 54-55).

Thesis--Lund Institute of Technology, 1993.

Thesis--Lund Institute of Technology, 1993.

Thesis (M. S.)--Mechanical Engineering, Georgia Institute of Technology, 2007. / Rosen, David, Committee Chair ; O'Connor, Jerry, Committee Member ; Fedorov, Andrei, Committee Member.

abstract: This thesis elaborates the application of carbon nanotubes (CNTs) and it is discussed in two parts. In the first part of the thesis, two types of CNTs inks for inkjet materials printer are prepared. They are both chemical stable and printable, effective and easily made. The sheet resistance of printed films decreases exponentially as the number of layers increases. In the second part of this study, CNTs/ZnO composite structures are fabricated to understand the electronic and optical properties. The materials were deposited by two different methods: drop-drying and RF magnetic sputtering system on flexible polymer substrates. To further increase the conductivity of the various layers of deposited CNTs films, electrical and optical characterizations are also done. This study establishes CNTs as a multi-functional semitransparent conductor, which can be deposited at room-temperature with other transparent conductive oxide (TCO) composites for application in flexible electronics and printed circuit and sensors. / Dissertation/Thesis / M.S. Materials Science and Engineering 2012