Effect of Block Copolymer Adsorption on Thin Film Dewetting Kinetics

Abstract

The stability of polystyrene (PS) films on silicon oxide is improved by blending with poly(styrene-block-methyl methacrylate) (PS-b-PMMA) having a short, adsorbing MMA block and long, dangling PS block (degree of polymerization N). Relative to PS (degree of polymerization P), hole growth velocity decreases by 5 and 17 times upon adding 0.05 volume fraction of PS-b-PMMA (φ) for N ∼ P and N ∼ 4P, respectively. In contrast to PS, holes approach a constant value and do not coalesce. The N ∼ 4P system provides better stabilization because of its broader interfacial width. For N ∼ P, hole velocity decreases as φ increases and then becomes constant for φ > 0.03. Relative to blends, holes grow faster in bilayers and eventually coalesce. AFM analysis shows that the PS hole floor is smooth whereas the blend floor contains patches. The film stabilizing effect of block copolymers can be attributed to a decrease in capillary driving force, entanglements at the matrix/copolymer interface, and brush grafting density.

Adsorption of Block Copolymers from Selective Solvents on Curved Surfaces

“…In order to provide additional degrees of freedom that would enable the control of structural properties of the adsorbed layer, recent work utilized systems that include block copolymers having blocks with dissimilar chemical features. [26][27][28] In these systems, polymer adsorption will be governed by the specific interfacial interactions of each block with each other, with the surface, and with the solvent.…”

Synthesis and Modified of Poly(Vinyl chloride) Contains Triazole Moieties and Studying the Optical Properties of New Polymers

“…Chlorinated polyethyleneadapt well with PVC where a high degree diffusion inpolymer which increases the impact properties [6,7]. Optical properties of polymer films are very important for many technological applications [8], ranging from protective coatings to paintings, microelectronic, semiconductors, and optoelectronic devices depending on the reflectance and transmittance properties of the films during their preparation [9,10].…”

Influences of chain heterogeneity on instability of polymeric thin films: Dewetting of polystyrenes, polychloromethylstyrenes and its copolymers

“…The dimension and position of the holes formed via this mechanism are random. Since many applications require continuous films, scientific community has explored the procedures to suppress the dewetting of polymeric thin films [20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36]. There are various factors that affect the stability of thin film, including polymer-substrate and interchain interactions [20,28,29,34], surface morphology of substrate [14] and the presence of nanoparticles [21,22,24,25].…”

“…It has been demonstrated that the difference between surface energy of substrate and polymers can be tuned by modifying the surface layer, achieved by utilizing polymer brushes [26,36] and other approaches [20,23,32,37]. Adding trace amount of diblock copolymers [27,33], dendrimer [30], hyperbranched [31] and long chain polymers [35] into system has also been shown to be an effective method to retard the dewetting.…”