Green poly(β-hydroxybutyrate)/starch nanocrystal composites: Tuning the nucleation and spherulite morphology through surface acetylation of starch nanocrystal

Gas-phase acylation of cellulose is an attractive method for modifying the surface properties of cellulosics. However, little is known concerning the regioselectivity of the chemistry, in terms of which cellulose positions are preferentially acylated and if acylation can be restricted to the surface, preserving crystallinities/morphologies. Consequently, we reexplore simple gas-phase acetylation of modern-day cellulosic building blocks – cellulose nanocrystals, pulps, regenerated fibre and aerogels. The gas-phase acetylation is shown to be highly regioselective for the C6-OH, is further supported with computational modelling. This contrasts with liquid-state acetylation, highlighting that the gas-phase chemistry is much more controllable, yet with similar kinetics to the uncatalyzed liquid-phase reactions. Furthermore, this method preserves both the native crystalline structure of cellulose and the supramolecular morphologies of even delicate cellulosic constructs (aerogel exhibiting retention of chiral cholesteric liquid crystalline phases). Therefore, we are convinced that this methodology will lead to more rapid adoption of precisely tailored and cellulosic materials

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Spherulite morphology in liquid crystals of polybenzylglutamates. Optical rotatory power and effect of magnetic field

Journal of Polymer Science Polymer Physics Edition ◽

10.1002/pol.1980.180180709 ◽

1980 ◽

Vol 18 (7) ◽

pp. 1599-1607 ◽

Cited By ~ 15

Author(s):

Dahyabhai L. Patel ◽

Donald B. Dupré

Keyword(s):

Magnetic Field ◽

Liquid Crystals ◽

Rotatory Power ◽

Optical Rotatory ◽

Spherulite Morphology ◽

Optical Rotatory Power

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Surface Acetylation of Polyamidoamine (PAMAM) Dendrimers Decreases Cytotoxicity while Maintaining Membrane Permeability

Bioconjugate Chemistry ◽

10.1021/bc0603889 ◽

2007 ◽

Vol 18 (6) ◽

pp. 2054-2060 ◽

Cited By ~ 198

Author(s):

Rohit B. Kolhatkar ◽

Kelly M. Kitchens ◽

Peter W. Swaan ◽

Hamidreza Ghandehari

Keyword(s):

Membrane Permeability ◽

Pamam Dendrimers ◽

Surface Acetylation

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Interfacial Effects on the Spherulitic Morphology of Isotactic Polystyrene Thin Films on Liquid Substrates

Advances in Materials Science and Engineering ◽

10.1155/2016/4849798 ◽

2016 ◽

Vol 2016 ◽

pp. 1-8

Author(s):

Takashi Sasaki ◽

Masaaki Nakagiri ◽

Satoshi Irie

Keyword(s):

Thin Films ◽

Nucleation Rate ◽

Silicone Oil ◽

Cold Crystallization ◽

Number Density ◽

Interfacial Effects ◽

Isotactic Polystyrene ◽

Primary Nucleation ◽

Atactic Polystyrene ◽

Spherulite Morphology

The influence of interfaces on the morphology of flat spherulites of isotactic polystyrene (iPS) grown in thin films on liquid substrates was investigated. Amorphous iPS thin films spin-cast from a solution were annealed for cold crystallization on glycerol and silicone oil (nonsolvents for iPS). The number density of grown spherulites was revealed to be higher on the glycerol substrate than on the silicone oil substrate. This implies that the primary nucleation rate of crystallization is greater at the iPS/glycerol interface than at the iPS/silicone oil interface. The results may be consistent with the previous findings that concern the molecular interaction between atactic polystyrene and nonsolvents at the interface. In some cases, holes were formed in the thin films during the cold crystallization due to dewetting, which also significantly affect the spherulite morphology via, for example, transcrystallization.

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An unusual spherulite morphology induced by nano-fillers from a concentrated cellulose/ionic liquid solution

RSC Advances ◽

10.1039/c5ra06740e ◽

2015 ◽

Vol 5 (55) ◽

pp. 44648-44651 ◽

Cited By ~ 9

Author(s):

Meichun Ding ◽

Jian Yu ◽

Jiasong He ◽

Jun Zhang

Keyword(s):

Ionic Liquid ◽

Liquid Solution ◽

Ionic Liquid Solution ◽

Spherulite Morphology

Unusual spherulites containing an eye-like region were induced by nano-fillers from concentrated cellulose solutions in a 1-allyl-3-methylimidazolium chloride ionic liquid.

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