C0jm00355g 4213..4222
نویسندگان
چکیده
Fundamental reaction processes between vapor-phase chemical precursors and high molecular weight polymers are important for polymer coating, encapsulation and surface modification. Using trimethylaluminium and water in an atomic layer deposition (ALD) exposure sequence, reactions between vapor-phase trimethylaluminium and common polymers with different substituents are quantified using in situ infrared transmission analysis. Exposing polypropylene to trimethylaluminium results in reactant uptake with minimal precursor/polymer reaction, but the precursor/water ALD sequence leads to subsurface alumina nucleation. A similar treatment to polyvinyl alcohol and polyamide-6 results in rapid precursor diffusion and significant reaction observed by IR, and the extent of reaction is consistent with results from in situ quartz crystal microgravimetry and transmission electron microscopy. Reacting trimethylaluminium with polyamide-6 leads to methyl group insertion into the amide carbonyl group and interaction with the hydrogen-bonded amine units. Multiple ALD reaction cycles produce film coatings on all polymers studied, but the coating structure depends strongly on the starting polymer composition. For the weakly interacting polypropylene, crosssectional transmission electron microscopy demonstrates enhanced sub-surface growth at 90 C as compared to that at 60 C, while images of coated polyamide-6 fibers showed that growth is not strongly temperature dependent in that range. Micrograph images of polyamide-6 samples exposed to extended TMA doses revealed significant modification of the fiber surface region, demonstrating that the precursor could diffuse and react to depths in excess of 100 nm into the surface of the polymer at 90 C. Improved understanding of specific precursor/polymer reaction pathways can be important to optimize the performance of conformal inorganic thin film coatings on polymers.
منابع مشابه
The permutation class Av(4213, 2143)
We determine the structure of permutations avoiding the patterns 4213 and 2143. Each such permutation consists of the skew sum of a sequence of plane trees, together with an increasing sequence of points above and an increasing sequence of points to its left. We use this characterisation to establish the generating function enumerating these permutations. We also investigate the properties of a...
متن کاملIdentification and Characterization of a Dual-Acting Antinematodal Agent against the Pinewood Nematode, Bursaphelenchus xylophilus
The pinewood nematode (PWN), Bursaphelenchus xylophilus, is a mycophagous and phytophagous pathogen responsible for the current widespread epidemic of the pine wilt disease, which has become a major threat to pine forests throughout the world. Despite the availability of several preventive trunk-injection agents, no therapeutic trunk-injection agent for eradication of PWN currently exists. In t...
متن کاملGRANT NUMBER DAMD17-94-J-4213 TITLE: Role of Parathyroid Hormone-Related Protein in Breast Cancer Mediated Osteolysis PRINCIPAL INVESTIGATOR:
متن کامل
Conservation Benefits of Marine Reserves are Undiminished Near Coastal Rivers and Cities
1 Australian Rivers Institute – Coast & Estuaries and School of Environment, Griffith University, Gold Coast, QLD 4222, Australia 2 School of Science & Engineering, University of the Sunshine Coast, Maroochydore, DC, QLD 4558, Australia 3 School of Biological Sciences, University of Queensland, St Lucia, QLD 4072, Australia 4 Commonwealth Scientific and Industrial Research Organization, Marine ...
متن کاملQuantifying the conservation value of seascape connectivity: a global synthesis
Australian Rivers Institute – Coast and Estuaries, and School of Environment, Griffith University, Gold Coast, Qld 4222, Australia, School of Science and Engineering, University of the Sunshine Coast, Maroochydore, Qld 4558, Australia, Biogeography Branch, National Oceanic and Atmospheric Administration, Silver Spring, MD 20910, USA, Marine Institute, Plymouth University, Plymouth PL4 8AA, UK, ...
متن کامل