Functional Thin Films Synthesized from Liquid Precursors by Combining Mist Chambers and Atmospheric-Pressure Plasma Polymerization

For the creation of thin films, the use of precursors in liquid phase offers a viable alternative when these chemicals are sensitive to high temperatures and phase changes. However, it requires appropriate liquid handling and deposition technologies capable of dispensing the fluid homogeneously to produce a uniform thin film. We report different tailor-made mist chamber designs integrated in an atmospheric-pressure plasma polymerization process for the synthesis of functional thin polymer films from liquid precursors. A systematic investigation, evaluated by performance indicators, is presented on the characteristics and suitability of metallic 3D-printed mist chambers depending on inner volume, geometry and surface post-treatment, for the deposition of a thin liquid monomer film. To assess the quality of the subsequently obtained plasma-polymerized (pp) films, their properties were characterized in terms of thickness, chemical composition, surface morphology and stability in aqueous environment. It was found that the specification of the mist chambers along with the plasma process parameters influences the pp film’s thickness, surface morphology and degree of monomer conversion. This study is one of the first demonstrations of a controllable process able to tune the cross-linked polymeric chains of plasma-polymers at atmospheric pressure, highlighting the opportunities of using mist chambers and plasma technology to discover tailored organic thin films to materials sciences and life sciences.

Sintesis Carbon Nanotube (CNT) Menggunakan Prekursor Bahan Alam Serta Modifikasi CNT Sebagai Komposit CNT/Resin Epoksi: Review

<p><em>Carbon Nanotube</em> (CNT) memiliki aplikasi potensial yang luas karena sifat kimia dan fisiknya yang sangat baik. CNT disintesis menggunakan prekursor cair dari bahan alam yang. Prekursor cair dari bahan alam dimungkinkan dapat mengganti prekursor berbasis minyak bumi. Minyak kamper, jarak, kayu putih, dan kelapa sawit digunakan sebagai reservoir karbon untuk menghasilkan CNT berdinding banyak (MWCNT). Berbagai metode telah digunakan untuk menghasilkan CNT, termasuk ablasi laser, <em>arc discharge</em> dan proses deposisi uap kimia (CVD). Ulasan ini menjelaskan pembuatan CNT menggunakan metode CVD dikarenakan metode ini adalah metode yang umum digunakan dan sederhana. MWCNT yang dihasilkan dimodifikasi untuk membentuk komposit dengan resin epoksi.</p><p><strong><em>Synthesis of Carbon Nanotubes (CNT) Using Natural Material Precursors and Modified CNTs as CNT/Epoxy Resin Composite: Review. </em></strong>Carbon Nanotubes (CNT) have wide potential applications due to their excellent chemical and physical properties. CNTs were synthesized using liquid precursors from natural materials possibly replacing petroleum-based precursors. Camphor, jatropha, eucalyptus oil, and palm oil are used as carbon reservoirs to produce multi-walled carbon nanotubes (MWCNT). A variety of methods have been used to produce CNTs, including laser ablation, arc discharge, and chemical vapor deposition (CVD) processes. This mini-review explained the manufacture of CNTs using the CVD method as a commonly used and simple method. The synthesized CNT is then modified to be applied to form a composite with epoxy resin</p>

In-Situ One-Step Direct Loading of Agents in Poly(acrylic acid) Coating Deposited by Aerosol-Assisted Open-Air Plasma

In biomaterials and biotechnology, coatings loaded with bioactive agents are used to trigger biological responses by acting as drug release platforms and modulating surface properties. In this work, direct deposition of poly(acrylic acid) coatings containing various agents, such as dyes, fluorescent molecules, was achieved by aerosol-assisted open-air plasma. Using an original precursors injection strategy, an acrylic acid aerosol was loaded with an aqueous aerosol and deposited on silicon wafers. Results clearly showed that agents dissolved in the aqueous aerosol were successfully entrapped in the final coating. The effect of aerosols concentration, flow rate, and treatment time, on the coating morphology and the amount of entrapped agents, was also investigated. It was demonstrated that this process has the potential to entrap a tunable amount of any sensible water-soluble agent without altering its activity. To the best of our knowledge, this is the first time that the loading of an aqueous aerosol in coatings deposited by plasma from a liquid aerosol precursor is reported. This innovative approach complements plasma deposition of coatings loaded with bioactive agents from aqueous aerosols with the use of non-volatile liquid precursors.

Plasma-molten Metal and/or Liquid Interactions for Materials/Chemical Processing

Several grand challenges in energy storage and conversion need the discovery of functional materials that many agree will be composed of complex compositions at nanoscale. In this regard, plasma based materials processing has been shown to be promising for combinatorial techniques and scalable processing. The use of plasma oxidation of liquid precursors allows for creation of metastable complex oxide particles with compositional control.1 A number of examples will be discussed in which the above two techniques are currently being used for accelerating the development of a variety of catalysts including electrocatalysts and materials for storage applications. This talk will highlight our efforts to understand the role of plasmas under two categories: (a) the synergistic effects hydrogen and nitrogen plasma interactions with molten metals;2 and (b) the oxygen plasma-liquid droplet interactions.3 To gain insights into these mechanisms we have studied the interaction of hydrogen and nitrogen plasmas with low melting point metals, primarily with gallium. Absorption/desorption experiments as well as theoretical-computational calculations were performed. Experiments have shown an increment of adsorbed gaseous species into the molten metal in the presence of plasmas. In the case of oxygen plasma-liquid droplet interactions for creating complex oxides, the role of solvated electrons, oxygen radicals and heating effects will be discussed. Finally, the use of plasmas for achieving liquid phase epitaxial growth of GaN and related materials will be discussed.4 Author acknowledge primary funding support from NSF Solar Project (DMS 1125909), and NSF EPSCoR (1355438). References 1. P. Ajayi, S. Kumari, D. Jaramillo-Cabanzo, J. Spurgeon, J. Jasinski and M.K. Sunkara, “A rapid and scalable method for making mixed metal oxide alloys for enabling accelerated materials discovery”, J. of Materials Research, 31 (11), 1596-1607(2016) 2. L. Carreon, D.F. Jaramillo-Cabanzo, I. Chaudhuri, M. Menon and M.K. Sunkara, “Synergistic interactions of H2 and N2 with molten gallium in the presence of plasma”, Journal of Vacuum Science and Technology A, 36, 021303 (2018). 3. P. Ajayi, M. Z. Akram, W. H. Paxton, J. B. Jasinski and M. K. Sunkara, “Nucleation and Growth Mechanisms During Complex Oxide Formation Using Plasma Oxidation of Liquid Precursors”, Submitted (2019) 4. Jaramillo, J. Jasinski and M. Sunkara, “Liquid Phase Epitaxial Growth of Gallium Nitride”, Crystal Growth and Design, 19, 11, 6577-6585(2019)

Statistical design of experiments for production and purification of vanillin and aminophenols from commercial lignin

Production and purification of vanillin from lignin using ion exchange, and subsequent conversion to aminophenol ionic liquid precursors.