Rapid, Efficient and Versatile Strategies for Functionally Sophisticated Polymers and Nanoparticles: Degradable Polyphosphoesters and Anisotropic Distribution of Chemical Functionalities

The overall emphasis of this dissertation research included two kinds of asymmetrically-functionalized nanoparticles with anisotropic distributions of chemical functionalities, three degradable polymers synthesized by organocatalyzed ring-opening polymerizations, and two polyphosphoester-based nanoparticle systems for various biomedical applications. Inspired by the many hierarchical assembly processes that afford complex materials in Nature, the construction of asymmetrically-functionalized nanoparticles with efficient surface chemistries and the directional organization of those building blocks into complex structures have attracted much attention. The first method generated a Janus-faced polymer nanoparticle that presented two orthogonally click-reactive surface chemistries, thiol and azido. This robust method involved reactive functional group transfer by templating against gold nanoparticle substrates. The second method produced nanoparticles with sandwich-like distribution of crown ether functionalities through a stepwise self-assembly process that utilized crown ether-ammonium supramolecular interactions to mediate inter-particle association and the local intra-particle phase separation of unlike hydrophobic polymers. With the goal to improve the efficiency of the production of degradable polymers with tunable chemical and physical properties, a new type of reactive polyphosphoester was synthesized bearing alkynyl groups by an organocatalyzed ring-opening polymerization, the chemical availability of the alkyne groups was investigated by employing click type azide-alkyne Huisgen cycloaddition and thiol-yne radical-mediated reactions. Based on this alkyne-functionalized polyphosphoester polymer and its two available click type reactions, two degradable nanoparticle systems were developed. To develop the first system, the well defined poly(ethylene oxide)-block-polyphosphester diblock copolymer was transformed into a multifunctional Paclitaxel drug conjugate by densely attaching the polyphosphoester block with azide-functionalized Paclitaxel by azide-alkyne Huisgen cycloaddition. This Paclitaxel drug conjugate provides a powerful platform for combinational cancer therapy and bioimaging due to its ultra-high Paclitaxel loading: \u3e 65 wt%), high water solubility: \u3e6.2 mg/mL for PTX) and easy functionalization. Another polyphosphoester-based nanoparticle system has been developed by a programmable process for the rapid and facile preparation of a family of nanoparticles with different surface charges and functionalities. The non-ionic, anionic, cationic and zwitterionic nanoparticles with hydrodynamic diameters between 13 nm to 21 nm and great size uniformity could be rapidly prepared from small molecules in 6 h or 2 days. The anionic and zwitterionic nanoparticles were designed to load silver ions to treat pulmonary infections, while the cationic nanoparticles are being applied to regulate lung injuries by serving as a degradable iNOS inhibitor conjugates. In addition, a direct synthesis of acid-labile polyphosphoramidate by organobase-catalyzed ring-opening polymerization and an improved two-step preparation of polyphosphoester ionomer by acid-assisted cleavage of phosphoramidate bonds on polyphosphoramidate were developed. Polyphosphoramidate and polyphosphoester ionomers may be applied to many applications, due to their unique chemical and physical properties

A Blockchain Framework for Preserving Music Intellectual Property Rights

The continuous strengthening of intellectual property protection has made the analysis of music intellectual property framework a research hotspot, and also promoted the integration of blockchain and intellectual property. The original IP protection framework could not solve the problem of music IP protection, and IP protection was ineffective. Therefore, this paper proposes a framework based on blockchain technology to analyze the protection of music intellectual property rights. Firstly, the blockchain server is used to store the music intellectual property rights, and the continuity judgment is made according to the characteristics of the intellectual property data to form the block data of the time series. Then, according to the intellectual property results stored in each server, the blockchain framework with different protection levels is compared with the intellectual property protection requirements. After simulation test and analysis, the framework based on blockchain technology can improve the security of music intellectual property data, reduce the tampering rate of property rights data, remove the centralization of intellectual property rights, and simplify the intellectual property protection process

Integrating Library Instruction into the Course Management System for a First Year Engineering Class: An Evidence-Based Study Measuring the Effectiveness of Blended Learning on Students’ Information Literacy Levels

This research examines students in a first-year engineering course who receive library instruction by using a newly developed online module and attending optional in-person tutorials. It aims to evaluate the outcomes of library information literacy instruction using this module combined with in-person help. Results show a significant improvement in information literacy skills from a pre-test to a post-test. Focus group and survey data indicate that most students preferred the self-paced learning style of the online module and that the content of the module helped them to conduct library research for the course. This study also considers best practices for online library instruction. A blended instruction approach provides students with the flexibility to learn from a variety of formats at their own pace and also reduces library staff workload, especially for a large course

Influence of Kaolinite Clay on the Chloride Diffusion Property of Cement-Based Materials

To constitute blended cement concrete with high chloride diffusion resistivity, the effects of kaolinite clay on the mechanical properties and chloride diffusivity of cement paste, mortar and concrete were investigated. Ordinary Portland cement was partially replaced by kaolinite clay at 0%, 1%, 3%, 5%, 7% and 9% by weight of cement. All blended cement-based samples were prepared using a w/c ratio of 0.5. The microstructure, workability, early-age and long-term flexural strength of pastes were tested. The chloride diffusivity of mortars was measured. And the compressive strength and chloride diffusivity of concrete were measured. Mercury Intrusion Porosimetry (MIP) was employed to evaluate porosity characteristics. Scanning Electron Microscopy (SEM) and Energy Dispersive Spectra (EDS) were applied to investigate the micro morphology and chemical element distribution inside the cement matrix, and the rapid chloride migration (RCM) method was applied to test chloride diffusivity. The MIP test results show that the addition of clay improves the micro-pore structure in the cement paste and limits the introduction of chloride ions. SEM imaging suggests that the kaolinite clay is acting as both filler and accelerator of cement hydration. It is found that the addition of clay alters the water requirement of normal consistency and the setting time of cement, whereas it has little influence on the soundness. Compared to the control, the flexural strength of cement paste with 1% kaolinite clay increased by 30.41%, 39.04%, 36.27% and 38.32% at 1, 3, 7 and 90 days, respectively. The 28-day flexural strength only increased slightly. It is observed that the cement mortar with clay has lower chloride diffusion coefficient values compared to the plain mortar, the 28-day diffusion coefficient of chloride ion View the MathML source(DCl-) of cement mortar is decreased by 53.03% with 5% clay. The increase in compressive strength of the cement concrete with clay is 12%, 13.5%, and 28.4% compared to the control at 1%, 3% and 5% addition, respectively. The chloride diffusion coefficient of cement concrete decreases exponentially with the clay addition. The reduction of chloride diffusion coefficient of cement concrete is 8.68% and 18.87% at 1% and 5% clay, respectively. The 28-day compressive strength increases linearly with the chloride diffusion coefficient of the concrete