Melt processing of chemically modified cellulosic fibres with only water as plasticiser: Effects of moisture content and processing temperature.

To replace petroleum-derived polymers with cellulose fibres, it is desirable to have the option of melt processing. However, upon heating, cellulose degradation typically starts before the material reaches its softening temperature. Alternatives to plastics should also, ideally, be recyclable via existing recycling streams.

Microscopic Insight into the Structure-Processing-Property Relationships of Core-Shell Structured Dialcohol Cellulose Nanoparticles.

In the quest to develop sustainable and environmentally friendly materials, cellulose is a promising alternative to synthetic polymers. However, native cellulose, in contrast to many synthetic polymers, cannot be melt-processed with traditional techniques because, upon heating, it degrades before it melts. One way to improve the thermoplasticity of cellulose, in the form of cellulose fibers, is through chemical modification, for example, to dialcohol cellulose fibers.

Enhancement of dissipated energy by large bending of an organic single crystal undergoing twinning deformation.

We demonstrate exceptional twinning deformation in a molecular crystal upon application of mechanical stress. Crystal integrity is preserved and the deformation is associated with a large bending angle (65.44°).

Versatile Ferroelastic Deformability in an Organic Single Crystal by Twinning about a Molecular Zone Axis.

Ferroelasticity involves the generation of spontaneous strain in a solid by the application of mechanical stress. The phenomenon has been well-studied in metal alloys but relatively neglected in organic solid-state chemistry. Herein we present multiple discrete modes of mechanical twinning and a mechanistic analysis of ferroelasticity in 1,4-diethoxybenzene.

Twinning ferroelasticity facilitated by the partial flipping of phenyl rings in single crystals of 4,4'-dicarboxydiphenyl ether.

Evidence of ferroelasticity in a non-planar organic molecular crystal is presented for 4,4'-dicarboxydiphenyl ether. Ferroelasticity has been demonstrated by the micro- and macroscopic mechanical characterization of single crystals, including recording of a full hysteretic stress-strain cycle. The underlying mechanism involves the partial flipping of phenyl rings.

Ferroelasticity in an Organic Crystal: A Macroscopic and Molecular Level Study.

Ferroelasticity has been relatively well-studied in mechanically robust inorganic atomic solids but poorly investigated in organic crystals, which are typically inherently fragile. The absence of precise methods for the mechanical analysis of small crystals has, no doubt, impeded research on organic ferroelasticity. The first example of ferroelasticity in an organic molecular crystal of 5-chloro-2-nitroaniline is presented, with thorough characterization by macro- and microscopic methods.

Activation-Dependent Breathing in a Flexible Metal-Organic Framework and the Effects of Repeated Sorption/Desorption Cycling.

A non-interpenetrated metal-organic framework with a paddle-wheel secondary building unit has been activated by direct thermal evacuation, guest exchange with a volatile solvent, and supercritical CO drying. Conventional thermal activation yields a mixture of crystalline phases and some amorphous content. Exchange with a volatile solvent prior to vacuum activation produces a pure breathing phase with high sorption capacity, selectivity for CO over N and CH , and substantial hysteresis.

A five-fold interpenetrated metal-organic framework showing a large variation in thermal expansion behaviour owing to dramatic structural transformation upon dehydration-rehydration.

A five-fold interpenetrated metal organic framework (MOF) has been shown to exhibit anomalous thermal expansion due to the combined effect of hinge-like motion and sliding of individual diamondoid networks. Upon dehydration, the MOF undergoes dramatic structural changes, thereby altering its thermal expansion behaviour to a large extent.

Uniaxial negative thermal expansion facilitated by weak host-guest interactions.

A nitromethane solvate of 18-crown-6 was investigated by means of variable-temperature single-crystal X-ray diffraction in response to a report of abnormal unit cell contraction. Exceptionally large positive thermal expansion in two axial directions and negative thermal expansion along the third was confirmed. The underlying mechanism relies exclusively on weak electrostatic interactions to yield a linear thermal expansion coefficient of -129 × 10(-6) K(-1), the largest negative value yet observed for an organic inclusion compound.

Reversible single-crystal to single-crystal polymorphic phase transformation of an organic crystal.

Two polymorphs of a substituted dihydroanthracene derivative were prepared by crystallization from different solvents. Each polymorph is reversibly interconvertible to the other by means of a single-crystal to single-crystal phase transformation.