Application of Microgels for Optical Tagging

In this paper we present results from our research into the use of microgel-based photonic crystals in an optical tagging application. The basis for this research is the phenomena of self-assembly of hydrogel nano- and microparticles (i.e., microgels) into colloidal crystal Bragg reflectors. Previous research has demonstrated the assembly of Bragg structures that are sensitive in the visible spectral region. This current research focuses on the extension of this process into the infrared regime and the use of these infrared-sensitive structures in the creation of an optical tag. In particular, the research effort emphasizes two primary areas: the development of nanoparticles that are infrared-sensitive and the casting of thin films comprised of these particles. We will also present theoretical data on the optical and physical characteristics of thin films comprised of these particles. This paper will present an overview of the program, outline the processes and issues addressed during our initial efforts in creating these infrared sensitive structures and present a summary of the computational results based on the theoretical analyses.https://digitalcommons.chapman.edu/sees_books/1003/thumbnail.jp

Synthesis of Discotic Columnar Side-Chain Liquid Crystalline Polymers by Ring-Opening Metathesis Polymerization (ROMP)

Discotic liquid crystalline polymers bearing alkoxy-substituted triphenylene moieties in the side-chain were synthesized by ring-opening metathesis polymerization using a well-defined ruthenium initiator. To elucidate the effect of backbone flexibility on the mesomorphism, norbornene and cyclobutene monomers containing triphenylene moieties were synthesized, which yielded the relatively rigid poly(norbornene)s and the more flexible poly(butadiene)s, respectively, after polymerization. To further increase the backbone flexibility, the poly(butadiene)s were hydrogenated using Crabtree's catalyst to yield triphenylene-substituted poly(butane)s. The mesomorphic behavior of the polymers has been investigated by differential scanning calorimetry (DSC) and powder diffraction X-ray scattering (wide angle X-ray scattering, WAXS). All polymers bearing a 2,3,6,7,19-pentakis(decyloxy)triphenylene-based mesogenic unit exhibit enantiotropic discotic hexagonal mesophases, while the pentoxy analogues do not display liquid crystalline behavior. No effect of backbone rigidity on the mesomorphism could be detected

Patterning electro-osmotic flow with patterned surface charge

This Letter reports the measurement of electro-osmotic flows (EOF) in microchannels with surface charge patterned on the 200 mu m scale. We have investigated two classes of patterns: (1) Those in which the surface charge varies along a direction perpendicular to the electric field used to drive the EOF; this type of pattern generates multidirectional flow along the direction of the field. (2) Those in which the surface charge pattern varies parallel to the field; this pattern generates recirculating cellular flew, and thus causes motion both parallel and perpendicular to the external field. Measurements of both of these flours agree well with theory in the Limit of thin double layers and low surface potential

Development and initial validation of a measure of metacognitive beliefs in health anxiety: The MCQ-HA

Metacognitive beliefs have been shown to correlate with emotional disorders and more recently have been implicated in health anxiety. Research exploring these beliefs have tended to use the Metacognition Questionnaire (MCQ), which is a general measure. To facilitate research on the metacognitive model applied to health anxiety the present study reports on the development and initial evaluation of a new specific metacognitive measure of health anxiety, the Metacognitions Questionnaire-Health Anxiety (MCQ-HA). Principal components analysis identified 14 suitable items to be explored. Subsequent exploratory factor analysis of the MCQ-HA identified three factors: “Beliefs that Thoughts can cause Illness”, “Beliefs about Biased thinking”, and “Beliefs that Thoughts are Uncontrollable”. Confirmatory factor analysis supported the three factor model with all selected goodness-of-fit statistics equivalent to or better than recommended values. Preliminary evidence suggests good internal-consistency, incremental, convergent and discriminant validity in relation to associated measures. The MCQ-HA appears to be a potentially useful predictor of health anxiet

Polymer backbone optimization of Alq3 functionalized polymers

Issued as final reportAlbemarle Corporatio