Recent insights into important factors that govern the semicrystalline morphology of crystallizable polymers, but have received less systematic attention, are reviewed. This concerns the influence of intracrystalline chain motion and the effect of entanglements in the amorphous phase. New perspectives on the thermodynamic driving forces underlying the structure formation are provided by computer simulations.

Semicrystalline polymers with and without intracrystalline chain dynamics have been suggested to display different morphological characteristics. Combined nuclear magnetic resonance and small angle X-ray experiments measurements reveal that polybutylene succinate belongs to the class of crystal-fixed polymers without this dynamics and confirm the existence of the expected morphology.

Crystallographic studies by X-ray diffraction are performed on a series of long chain polyamides. Different polymorphic states formed in bulk samples are identified in temperature-dependent measurements. Well oriented fibers are produced successfully by drawing of ram extruded filaments. Differences in the crystalline state between samples crystallized from bulk and under external forces are highlighted and discussed.

Combined fast scanning calorimetry (FSC) and IR spectroscopy reveal for the first time the molecular signatures of the initial stages of enthalpy relaxation and crystal nucleation occurring much earlier before the start of crystallization in polyethylene terephthalate. During enthalpy relaxation, the far-reaching Coulomb interactions between the polar carbonyl (C═O) moieties are active while crystal nucleation is dominated by π–π interactions.

This perspective discusses recent achievements in the theoretical and experimental investigation of two phenomena of interface-induced crystallization in polymers – prefreezing and heterogeneous nucleation. Special attention is paid to the influence of substrate-material interactions on crystallization temperature, crystal orientation, and semicrystalline morphology.

Structure formation of two different stereoisomers such as atactic (at)- and isotactic (it)- poly(methacrylic acid) (PMAA) in thin films prepared by Langmuir/LB and suspension-cast methods is demonstrated. While the at-PMAA dissolved in the water surface, the it-PMAA forms Langmuir/LB films with amorphous nano-entities during compression. The crystallization is only identified in it-PMAA in suspension-cast films.

Crystallization in nanometer-sized polymer droplets is probed by a nano-dielectric spectroscopy setup. Spin-cast droplets down six chains each crystallize at reduced temperature according to classical nucleation theory. Aggregates, which are prepared via gold-nanoparticle deposition and a grafting-to reaction leading to a narrow volume distribution, consist of ten chains and exhibit no crystallization.

Using a recently devised binary-tree Monte Carlo method, simulations of long hard-sphere polymer chains with up to 10⁷ repeat units subject to free and periodic boundary conditions are reported in two to five dimensions. Scaling analyses of end-to-end distance, radius of gyration, and their ratio provide strong support of universality. For measuring entropy and its derivatives new methods are introduced.

Stochastic Approximation Monte Carlo simulations are used in combination with the intermediate resolution protein model PRIME20 to simulate systems of two Polyglutamine chains of different chain lengths. Analysis of the specific heat and structural observables reveals an aggregation and folding transition around room temperature. The hydrogen bond contact probabilities reveal a chain length dependent aggregation route.

Molecular dynamics simulations using the Slipids and CHARMM36 force fields generate different NMR order parameters for alkanes incorporated in lipid bilayers. The predicted NMR order parameters are highly sensitive to the 1–4 electrostatic interactions and suggest that a reduction of the alkyl partial charges in CHARMM36 results in better performance for the longer alkyl chains.

Thermoplasmonics, that is, the generation of heat with plasmonic nanostructures has recently found new applications in the manipulation of single macromolecules and protein aggregates. Recent developments are reviewed with a specific focus on thermophoretic trapping of single nano-objects and highlight the connection to temperature induced hydrodynamic effects providing new perspectives for the field.

The contact between phenylalanine 19 and leucine 34 in Aβ molecules is highly conserved suggesting a particular significance for Aβ misfolding and, in turn, for its neurotoxicity. Point mutations in Aβ peptides at the contact F19−L34 help understanding this importance. The amyloid structure of Aβ is very robust against many modifications, but the toxicity highly depends on the F19−L34 contact.

Nature is full of interfaces. Its physicochemical properties and biological activities control the function of biomolecules, such as peptides and proteins. In this review, the authors take a look at the influence of hard solid surfaces, nanoparticles, and soft matter interfaces, such as cell membranes, on peptide corona formation, peptide self-assembly and amyloid fibril formation.

Hybrid-vesicles (≈100 nm), bearing cholesterol-/glycerol- anchored poly(di(ethylene glycol)_macrylates)_n embedded in a 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) bilayer, inhibit amyloidic transformation of the Aβ_1-40 peptide by prolonging lag- (t_lag) and half times (t_1/2) of Aβ_1-40 fibrillation. The hybrid-vesicles promote the morphological transformation of Aβ_1-40 fibrils to either amorphous or lead to a full inhibition of their formation.

Macromolecular-crowded environments contrastively effect primary and secondary fibrillation pathways of the Alzheimer peptides. Occluded areas modify the rates of nucleation and growth revealing weak peptide-specific interactions of Aβ monomers and fibrils with the crowder molecules. Contrary, the entropic gain of the fibrillation process is mainly featured by primary nucleation processes.

Kinetic analysis of amyloid formation by the parathyroid hormone PTH₈₄ reveals an intriguing network of individual processes which depend on the peptide concentration. On the basis of various ThT detected fibrillation kinetics, a monomer-oligomer equilibrium is hypothesized to explain concentration dependent fibril formation and polymorphism, inhibition effects and the first case of a competition of primary with secondary nucleation.

The eye lens gets continuously exposed to UV-B light during human lifespan. As early damage of still soluble and globular γD-crystallin, a local unfolding of the aromatic cluster in the N-terminal domain around tyrosine 17 and 29 can be identified by NMR spectroscopy. Eye lens extracts of cataract patients reveal some remaining photoprotective capacity.

Coiled coils are key building blocks of self-assembled biogenic materials. Under load, coiled coils frequently undergo a structural transition from an α-helical structure to mechanically stronger β-sheets. This α-β transition is absent when shearing individual synthetic coiled coils with single-molecule force spectroscopy. Molecular dynamics simulations suggest that interchain sliding dominates over β-sheet formation on the chain separation pathway.

Poly(amino acids) allow to study the assembly and function of proteins. The folding and aggregation of oligo- and poly-glutamic acids, aspartic acids and α-aminoisobutyric acids and the impact of solvents and functional groups is reviewed. Embedded at the cross-section of protein fibrillation and supramolecular polymers, these molecules allow the future design of functional biomaterials, guiding further into amyloid fibrillation.