The research of copolymerization of ethylene with polar monomers catalyzed by group 4 metal complexes has gain substantial achievement, and the functional polyolefins, produced through the various structures of the catalysts and polar monomers, have already shown their unique applications in multiple fields. There are kinds of effective strategies to improve copolymerization activity and polar monomers incorporation: the structures of group 4 catalysts have been expanded from metallocenes to half-metallocenes and non-metallocenes; the new cocatalysts and catalytic systems have been developed; polar monomers are pretreated by masking agents; the functional groups of polar monomers have been largely enriched. In this review, the copolymerization of ethylene with polar monomers catalyzed by group 4 metal complexes are concluded and compared, and we are looking forward to summarizing the relationship between structure and reactivity of catalysts and providing advice for the design of catalysts. Moreover, the properties and potential applications of polar functionalized polyolefins are introduced.

Chitosan is cancer cytotoxic. It induces apoptosis/necrosis/autophagy and immuno-responses, and mitigates angiogenic and metastasis tendency of cancer cells. The lower molecular weight chitosan induces apoptosis, whereas the higher molecular weight chitosan exerts apoptosis and necrosis. Transforming chitosan into nanoparticles raises its anti-cancer efficacy with mode of cancer cell death governed by particle size to a greater extent than chitosan molecular weight. The larger nanoparticles tend to exert apoptosis. The smaller nanoparticles mediate necrosis. “Drug-free” small nanoparticles constituted of lower molecular weight chitosan are more cytotoxic than those of larger chitosan molecules/particles in vitro and in vivo, with no clear relationship between the deacetylation degree and zeta potential of nanoparticulate chitosan with anti-cancer activity. “Drug-free” chitosan nanoparticles are potentially as viable as the drug-loaded chitosan nanoparticles but with reduced systemic adverse effects. Their anti-cancer efficacy can be modulated through particle dose adjustment with lower risks of harmful effects than drugs and without processing hurdles faced in the development of drug-loaded chitosan nanoparticles such as low aqueous drug solubility, poor drug encapsulation, premature drug release and drug absorption, and drug instability with toxic metabolite formation.

Displays are an effective way for humans to recognize information instantly and intuitively without linguistic barriers. Electrical sensors detect diverse human and environmental changes through variations in electrical signals; these data are delivered to a display connected to a sensor via a microprocessor, facilitating human/machine interface technologies. The development of an innovative one-integrated platform with optimized architectures, where a sensor and a display are converged, is essential for achieving efficient and rapid information management with low power consumption. These integrated stimuli-adaptive and human-interactive sensing displays (HISDs) electrically detect external stimuli and display an optical visualization simultaneously. Among numerous materials suitable for stimuli-adaptive displays and HISDs, self-assembled photonic crystals (PCs) of block copolymers (BCPs) are promising because of their structural colors (SCs) resulting from constructive interference of incident light. This review provides a comprehensive overview of recent developments in stimuli-adaptive SC displays using self-assembled BCP PCs. The responses of BCP SC displays, operating in liquid cells and solid-type films, to various external stimuli are described. Furthermore, emerging HISDs based on BCP PCs are discussed wherein external stimuli are electrically detected and simultaneous visualization of stimuli-adaptive SCs occurs. A perspective on the development of next-generation stimuli-adaptive BCP SC displays and HISDs is also provided.

With the gradual deepening of the concept of sustainable development, the world is transitioning from an energy economy driven by fossil fuels to one that is supplied by more renewable and sustainable materials. Consequently, scientists, engineers, the public, and government agencies have increased their focus on the sustainable and renewable materials derived from natural resources. Terpenoids, a category of natural products existed in plants, microorganisms and marine animals, have numerous modification sites and diverse functions. It can be used to create sustainable materials, which is able to simplify the synthesis process of materials while also giving them a distinctive stereoscopic configuration, superior bioactivity, and biocompatibility, allowing for greater application in tissue engineering, surface coating, flexible electronic devices, and other applications. Depending on the different application fields of terpenoids, the focus of this review is to shed light on the recent advances in the preparation, properties, and development directions of sustainable and multifunctional materials from terpenoids, including 1) terpenoid-derived thermoplastics, 2) terpenoid-derived cross-linked polymers, and 3) terpenoid-derived supramolecular materials. This review aims to raise attention to natural terpenoids, promote their exploitation and utilization, and provide more alternatives for the advancement of sustainable functional materials.

Bio-based semicrystalline polylactide (PLA) has a growing value as a substitute for fossil-based polyesters in technical applications and as a biocompatible material in medicine. The complexity of the behavior of PLA, determined by the presence of different stereoisomers, the role of electrostatic interactions, and its slow crystallization rate, makes computer simulations an important tool to discover new approaches to control the properties of PLA-based materials. The goal of this review is to summarize the efforts to simulate PLA materials with different levels of detail, including the quantum mechanical approach, all-atom modeling, and coarse-grained particle models. We focus on the validation of the models and the ways to cross-check the results with other simulation and experimental data. Special attention is devoted to the simulations of PLA in the presence of water, which provide insights into molecular mechanisms of hydrolytic degradation of PLA, especially at the initial stage, when the structural changes can not yet be detected by experimental methods. Ultimately, the selection of the appropriate simulation methods can facilitate material design, by combining the throughput and level of detail necessary for the job.

The need for achieving sustainable technologies has encouraged research on renewable and biodegradable materials for novel products that are clean, green, and environmentally friendly. Nanocellulose (NC) has many attractive properties such as high mechanical strength and flexibility, large specific surface area, in addition to possessing good wet stability and resistance to tough chemical environments. NC has also been shown to easily integrate with other materials to form composites. By combining it with conductive and electroactive materials, many of the advantageous properties of NC can be transferred to the resulting composites. Conductive polymers, in particular poly(3,4-ethylenedioxythiophene:poly(styrene sulfonate) (PEDOT:PSS), have been successfully combined with cellulose derivatives where suspensions of NC particles and colloids of PEDOT:PSS are made to interact at a molecular level. Alternatively, different polymerization techniques have been used to coat the cellulose fibrils. When processed in liquid form, the resulting mixture can be used as a conductive ink. This review outlines the preparation of NC/PEDOT:PSS composites and their fabrication in the form of electronic nanopapers, filaments, and conductive aerogels. We also discuss the molecular interaction between NC and PEDOT:PSS and the factors that affect the bonding properties. Finally, we address their potential applications in energy storage and harvesting, sensors, actuators, and bioelectronics.

To date, numerous strategies have been developed to remove hazardous gaseous components like volatile organic compounds (VOCs) from the airstream. Adsorption technology has been used as an effective approach for the abatement of VOCs for over 30 years. Hyper-cross-linked polymers (HCPs) with permanent porosity, adjustable surface functional groups, and desired physical/chemical properties are recognized to have great potential for the adsorption of VOCs. In this review, the recent research advances achieved in the development of HCPs as adsorbents for the removal of VOCs are discussed with an emphasis on the following aspects: (1) properties of HCPs governing their adsorption performances, (2) removal mechanism of VOCs by HCPs, (3) advantages and shortcomings of HCPs for VOC adsorption, and (4) performance evaluation among HPCs (relative to other adsorption systems). Furthermore, the review was conducted to establish the “property-application” relationships to promote and encourage future research on the formulation of innovative HCP-based adsorptive materials for VOC removal.

The homopolymer of 2-isopropyl-2-oxazoline (iPrOx) and iPrOx copolymers are extensively studied in recent years, and the interest on them is still growing. Poly(2-isopropyl-2-oxazoline) (PiPrOx), known as thermoresponsive pseudopeptide, exhibits a phase transition in aqueous solution at a temperature near human body temperature and is nontoxic to many cell lines. These facts make this polymer potentially attractive for many bioapplications. PiPrOx is similar in chemical structure to poly(N-isopropylacrylamide) (PNIPAM) and is considered as the alternative to this so-called “gold standard” thermoresponsive polymer, however significant differences in properties of these two polymers are worth attention. To control the properties, that directly translate into application possibilities, iPrOx was copolymerized with a wide range of different monomers, and, optionally, the obtained copolymers have been variously modified. This review summarizes the few-years-back research accomplishments and progress in studies on PiPrOx and iPrOx-based copolymers. Considering the recent developments, the properties of iPrOx-based (co)polymers are shown, aiming at promoting their great potential in the biomedical field. Having gathered the information on modification possibilities, structure-property relationship and applications, especially in the biomedical field, a bit of speculation on the future prospects of iPrOx-based (co)polymers is given.

This manuscript summarizes the extensive research and new advancements on gelatin and gelatin-based nanocomposites. In the first part, various modifications including physical, chemical, and enzymatic modifications of gelatin were summarized, with an emphasis on the effect of these modifications on their structures and properties. Recently, many gelatin-based nanocomposites have been prepared and characterized. They found many important applications in various scientific fields namely drug controlled release, biosensor, food packaging, water treatment, cell imaging, cell proliferation, tissue engineering, and in disease and cancer diagnosis and treatment. Gelatin based nanocomposites have superior physico-chemical properties including tensile strength, conductivity, anti-microbial properties, anti-water permeation properties, barrier properties compared to gelatin alone. In the second part, we focus on the recent researches dealing with different aspects of gelatin-based nanocomposites, including their preparation, characterization, small and large deformation mechanical properties, and application.

Polyamides (PAs) are repeatedly exposed to environments of varying humidity throughout their service life. Due to their hygroscopic nature, moisture diffusion can alter the polymer properties, sometimes irreversibly. It has been previously found that the effect of transport of water on the structure, morphology, and physical properties of polymers is not negligibly small. In certain semi-crystalline polyamides, the diffusion coefficient has been shown to be governed by the local chain dynamics (β relaxation). The final molecular weight of PAs achieved after melt processing is a result of the equilibrium between the forward and reverse polycondensation depending on the water concentration. With the growing demand for unreinforced and reinforced polyamides as well as polyamide fibers in high-performance applications, it is critical to understand the physics of the interaction between water molecules and polymer or composite systems. This article reviews the existing literature about polyamide-water interactions with a focus on the governing physical laws of moisture transport within the polyamide matrix, drying kinetics, and dynamics of water in the polymer system. The implications of moisture on the processing and properties of the polyamides class of materials are also discussed, suggesting the need for best practices in instrumentation and control.