Growth of monolayered poly(l — lactide) lamellar crystals on a substrate

Abstract

Hydroxyl groups were introduced onto the surface of a silicon wafer by O 2 plasma treatment. Poly(l -lactide) (l -PLA) was attached onto the surface-modified silicon wafer by the ring-opening polymerization of l -lactide using the hydroxyl group as an initiator. Lamellar single crystals of l -PLA were grown directly on the l-PLA-attached silicon wafer from a 0.025% solution in acetonitrile at 5 o C. A well-separated, lozenge-shaped, monolayered lamellar single crystal was prepared because the l -PLA-attached silicon wafer acts as an initial nucleus.

Morphological Study on Mechanical Deformation and Alkaline Hydrolysis of Solution-Grown Poly(l-lactide) Crystals

“…The strong intensity of electron reflection indicates that molecular packing is very tight. A similar crystal morphology was observed when l-PLA attached substrate was grown [6]. Figure 2 shows atomic force microscopic images of l-PLA SGC after alkaline hydrolysis at 0.1 N NaOH.…”

Oppositely Synchronized Lamellar Bending in Poly(l‐lactic acid) Versus Poly(d‐lactic acid) Blended with Poly(1,4‐butylene adipate)

“…PLLA has been reported to form single crystals either by solution‐growth or melt‐crystallization of ultrathin films . Two different shapes of PLLA single crystals have been identified: i) hexagonal and ii) lozenge crystals of either monolayer or multilayer lamellae. Mono‐lamellae of lozenge‐shaped and hexagon‐shaped crystals have a thickness of about 9–12 nm .…”

New biodegradable materials produced by ring opening polymerisation of poly(l-lactide) on porous silicon substrates

“…As thay degrade in vivo, they form lactic acid which is tolerated by the body as it is naturally produced during glycolysis [15][16][17][18][19][20]. These properties have made polylactides and their copolymers the focus of many research groups for the production of biomaterials for drug delivery and tissue engineering [21][22][23][24][25][26][27][28]. Some more recent examples of the use of poly(l-lactide) PLLA includes the work of Chen et al who functionalised multi-walled nanotubes with PLLA of various molecular weights using both a grafting-to [29] and a grafting-from [30] approach.…”