Influence of solvent and molecular weight on thickness and surface topography of spin‐coated polymer films

Abstract

The influence of polymer molecular weight, molecular weight distribution, and polymer‐solvent interactions on the thickness and topography of spin‐coated polymer films was examined. For films prepared from dilute solutions, highly volatile solvents or fair or “poor” solvents for the polymer adversely affect film surfaces causing nonuniformities (waves) to appear. However, if the concentration of these solutions is increased to approximately the concentration at which entanglements are formed, nearly uniform films are produced even if the solvent employed is highly volatile, such as dichloromethane. When toluene is employed as the solvent, which has a relatively low volatility and therefore forms nearly flat film surfaces, films prepared from dilute solution were found to have thicknesses, h, proportional to η o0.34 Ω−0.49 for polystyrene and η o−0.39 Ω−0.49 for poly(methylmethacrylate) where ηo is the zero‐shear rate solution viscosity and Ω is the rotational speed at which the films were prepared. These results suggest that the exponents associated with ηo and Ω may be nearly independent of the type of polymer used as long as flat films are produced. Finally, the molecular weight parameter most important in controlling final film thickness for films made from dilute solutions is Mv, the viscosity‐average molecular weight.

Phospholipid Polymer Multilayered Hydrogels Containing Cells for Cancer Drug Screening

“…When increasing the spin speed between 1000 and 3000 rpm, the adsorbed amount of the polymer was decreased. This further caused the decrease of thickness, which was usually observed in the spin-assisted technique [8,9]. Although uniform multilayer hydrogels could be formed at spin speed of 2000 rpm and 3000 rpm, hydrogel layer was too thin to hold cells in the case of 3000 rpm (data not shown).…”

Efek Jenis Pelarut pada Sifat Optik, Morfologi Permukaan dan Koefisien Waveguide Loss dari Pandu Gelombang Planar Polimer Terkonjugasi MEH-PPV

“…Film tipis untuk pandu gelombang planar harus transparan, mempunyai indeks bias dan ketebalan yang homogen, mempunyai permukaan yang halus serta memiliki koefisien waveguide loss α gw < 1 dB/cm. Mendapatkan film tipis yang berkualitas baik merupakan kendala utama untuk aplikasi, sehingga banyak upaya yang dilakukan berkaitan dengan hal tersebut [9][10][11].…”

“…Film tipis untuk pandu gelombang planar harus transparan, mempunyai indeks bias dan ketebalan yang homogen, mempunyai permukaan yang halus serta memiliki koefisien waveguide loss α gw < 1 dB/cm. Mendapatkan film tipis yang berkualitas baik merupakan kendala utama untuk aplikasi, sehingga banyak upaya yang dilakukan berkaitan dengan hal tersebut [9][10][11].Salah satu metoda pembuatan film tipis polimer yang banyak dipakai adalah spin-coating [8]. Pada metoda tersebut terdapat beberapa parameter yang dapat dikontrol antara lain jenis pelarut, konsentrasi larutan, temperatur dan kecepatan serta waktu rotasi.…”

Estimating the thickness of hydrated ultrathin poly(o-phenylenediamine) film by atomic force microscopy

“…the infra-red spectrophotometer [20], the alpha-step profiler [21], the laser-ultrasound technique [22], the ellipsometry [23], the optical guided wave [16], the optical reflectance methodology [24], the electropolymerization charge (24 mC/cm 2 , ca. 0.1 m thick for polypyrrole) [25], etc.…”