Explore the vast range of titles available.

PBS, an acronym for poly (butylene succinate), is an aliphatic polyester that is attracting increasing attention due to the possibility of bio-based production, as well as its balanced properties, enhanced processability, and excellent biodegradability. This brief review has the aim to provide the status concerning the synthesis, production, thermal, morphological and mechanical properties underlying biodegradation ability, and major applications of PBS and its principal copolymers.

This work aimed to study the influence of the polybutylene succinate (PBS) content on the physical, thermal, mechanical, and chemical properties of the obtained polylactic acid (PLA)/PBS composite fibers. PLA/PBS blend fibers were prepared by a simple melt-blown process capable of yielding nanofibers. Morphological analysis revealed that the fiber size was irregular and discontinuous in length. Including PBS affected the fiber size distribution, and the fibers had a smoother surface with increased amounts of added PBS. Differential scanning calorimetry analysis (DSC) revealed that the crystallization temperature of the PLA sheet (105.8 °C) was decreased with increasing PBS addition levels down to 91.7 °C at 10 wt.% PBS. This suggests that the addition of PBS may affect PLA crystallization, which is consistent with the X-ray diffraction analysis that revealed that the crystallinity of PLA (19.2%) was increased with increasing PBS addition up to 28.1% at 10 wt% PBS. Moreover, adding PBS increased the tensile properties while the % elongation at break was significantly decreased.

Polylactide (PLA), poly(butylene succinate) (PBS) and blends thereof have been researched in the last two decades due to their commercial availability and the upcoming requirements for using bio-based chemical building blocks. Blends consisting of PLA and PBS offer specific material properties. However, their thermodynamically favored biphasic composition often restricts their applications. Many approaches have been taken to achieve better compatibility for tailored and improved material properties. This review focuses on the modification of PLA/PBS blends in the timeframe from 2007 to early 2019. Firstly, neat polymers of PLA and PBS are introduced in respect of their origin, their chemical structure, thermal and mechanical properties. Secondly, recent studies for improving blend properties are reviewed mainly under the focus of the toughness modification using methods including simple blending, plasticization, reactive compatibilization, and copolymerization. Thirdly, we follow up by reviewing the effect of PBS addition, stereocomplexation, nucleation, and processing parameters on the crystallization of PLA. Next, the biodegradation and disintegration of PLA/PBS blends are summarized regarding the European and International Standards, influencing factors, and degradation mechanisms. Furthermore, the recycling and application potential of the blends are outlined.

In this paper, the influence of the various degradation conditions, on the molecular and supramolecular structure of polybutylene succinate (PBS) and polybutylene succinate adipate (PBSA) copolymer during degradation is described. The experiment was carried out by the use of injection molded samples and normalized conditions of biodegradation in soil, composting and artificial weathering. Materials were studied by size-exclusion chromatography (SEC) coupled with multiangle laser light scattering (MALLS) detection and wide-angle X-ray diffraction (WAXD). Additionally, the physical and mechanical properties of the samples were determined. The performed experiments clearly show difference impacts of the selected degradation conditions on the macroscopic, supramolecular and molecular parameters of the studied aliphatic polyesters. The structural changes in PBS and PBSA explain the observed changes in the physical and mechanical properties of the obtained injection molded samples.

Compression molded biodegradable films based on poly(butylene succinate) (PBS) and poly(butylene adipate-co-terephthalate) (PBAT) at varying weights were prepared, and their relevant properties for packaging applications are here reported. The melt rheology of the blends was first studied, and the binary PBS/PBAT blends exhibited marked shear thinning and complex thermoreological behavior, due to the formation of a co-continuous morphology in the 50 wt% blend. The films were characterized by infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), mechanical tensile tests, scanning electron microscopy (SEM), and oxygen and water vapor permeability. PBS crystallization was inhibited in the blends with higher contents of PBAT, and FTIR and SEM analysis suggested that limited interactions occur between the two polymer phases. The films showed increasing stiffness as the PBS percentage increased; further, a sharp decrease in elongation at break was noticed for the films containing percentages of PBS greater than 25 wt%. Gas permeability decreased with increasing PBS content, indicating that the barrier properties of PBS can be tuned by blending with PBAT. The results obtained point out that the blend containing 25 wt% PBS is a good compromise between elastic modulus (135 MPa) and deformation at break (390%) values. Overall, PBS/PBAT blends represent an alternative for packaging films, as they combine biodegradability, good barrier properties and reasonable mechanical behavior.

Lead sulfide (PbS) presents large potential in thermoelectric application due to its earth‐abundant S element. However, its inferior average ZT (ZTave) value makes PbS less competitive with its analogs PbTe and PbSe. To promote its thermoelectric performance, this study implements strategies of continuous Se alloying and Cu interstitial doping to synergistically tune thermal and electrical transport properties in n‐type PbS. First, the lattice parameter of 5.93 Å in PbS is linearly expanded to 6.03 Å in PbS0.5Se0.5 with increasing Se alloying content. This expanded lattice in Se‐alloyed PbS not only intensifies phonon scattering but also facilitates the formation of Cu interstitials. Based on the PbS0.6Se0.4 content with the minimal lattice thermal conductivity, Cu interstitials are introduced to improve the electron density, thus boosting the peak power factor, from 3.88 μW cm−1 K−2 in PbS0.6Se0.4 to 20.58 μW cm−1 K−2 in PbS0.6Se0.4−1%Cu. Meanwhile, the lattice thermal conductivity in PbS0.6Se0.4−x%Cu (x = 0–2) is further suppressed due to the strong strain field caused by Cu interstitials. Finally, with the lowered thermal conductivity and high electrical transport properties, a peak ZT ~1.1 and ZTave ~0.82 can be achieved in PbS0.6Se0.4 − 1%Cu at 300–773K, which outperforms previously reported n‐type PbS. Cu interstitial doping is realized in n‐type PbS‐based thermoelectric material by expanding its lattice space, resulting in synergistically optimized carrier and phonon transport properties, thus contributing to a high ZTave value of 0.82 at 300–773 K.

Toward the end of the century, plastic waste treatment and recycling would be major issue to be addressed. Thus, to overcome the problem of polymer non-biodegradability, study and application of biodegradable polymers is important. Biodegradable polymers are those which can be broken down into smaller oligomers or monomers upon action of radiation, moisture, enzymes and chemicals. Poly(butylene) succinate (PBS) is one of the biodegradable polymers manufactured and studied for a long time. This review majorly focuses on its synthesis, blends, copolymers, composites, biodegradation studies, applications and processability. PBS copolymers are synthesized using multiple approaches such as monomer, polymer and application based. PBS blends are studied with PP, poly(propylene carbonate), Soy protein isolate and poly(lactic) acid. The PBS and its blends find its application in agricultural films, packaging, tableware, and biomedical applications. PBS composites were prepared using synthetic organic, inorganic fillers and bio-based fillers to improve its mechanical performance, flame retardancy, biodegradabilit,y etc., based on type of reinforcement. Biodegradability is one the property of PBS which will help in maintaining circular economy and sustainability. Graphical abstract

In this work, PbS and PbS/CdS core–shell quantum dots (QDs) were synthesized by a new photochemical approach. Prepared QDs were characterized by means of x-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive x-ray analysis (EDAX), UV–Vis, and Z-scan analyses. Synthesized QDs were in a cubic phase with a spherical morphology, and the crystallite sizes are estimated using the strain–size method. A uniform shift of Bragg diffraction peaks and quenching (200) Bragg plane are interpreted as the growth of the CdS shell. Linear optical properties were investigated using Urbach analysis and Tauc formula. It was found that the density of states of QD conduction and valence bands are three dimensional. The estimated sizes of PbS QDs and PbS/CdS using exciton absorption peaks at room temperature are 1.8 and 2.7 nm, respectively, which are in good agreement with the strain–size plot analysis. The growth of the CdS shell resulted in a considerable decrease in the nonlinearity refractive index and a significant increase in the nonlinear absorption.

Fabrication of heterostructures by merging two or more materials in a single object. The domains at the nanoscale represent a viable strategy to purposely address materials’ properties for applications in several fields such as catalysis, biomedicine, and energy conversion. In this case, solution-phase seeded growth and the hot-injection method are ingeniously combined to fabricate TiO2/PbS heterostructures. The interest in such hybrid nanostructures arises from their absorption properties that make them advantageous candidates as solar cell materials for more efficient solar light harvesting and improved light conversion. Due to the strong lattice mismatch between TiO2 and PbS, the yield of the hybrid structure and the control over its properties are challenging. In this study, a systematic investigation of the heterostructure synthesis as a function of the experimental conditions (such as seeds’ surface chemistry, reaction temperature, and precursor concentration), its topology, structural properties, and optical properties are carried out. The morphological and chemical characterizations confirm the formation of small dots of PbS by decorating the oleylamine surface capped TiO2 nanocrystals under temperature control. Remarkably, structural characterization points out that the formation of heterostructures is accompanied by modification of the crystallinity of the TiO2 domain, which is mainly ascribed to lattice distortion. This result is also confirmed by photoluminescence spectroscopy, which shows intense emission in the visible range. This originated from self-trapped excitons, defects, and trap emissive states.

Glomerella leaf spot (GLS), a fungal disease caused by Colletotrichum fructicola, is a major destructive disease of apples but research on control measures is limited. Melatonin (MT) is a phytohormone-like compound that affects plant growth and stress response but is prone to light-induced degradation, resulting in low stability and efficacy. Therefore, we developed a melatonin silicon-based nanomaterial (MT@SiO2) to enhance the stability of melatonin and increase its potential use on plants. Our results indicated that MT@SiO2 significantly enhanced apple leaf resistance to GLS. We demonstrated that MT@SiO2 at an optimal concentration of 50 μM significantly mitigated GLS infection in 'Gala' apples by elevating the level of salicylic acid. The core transcription factor gene MdNAC32 was identified in our transcriptome analysis and found to respond to both GLS infection and MT@SiO2 treatment. MdNAC32 directly activates the transcription of MdPBS1/2 which promotes the synthesis of SA. Transient overexpression and silencing experiments demonstrated that MdPBS1/2 positively regulates GLS resistance. In addition, we found that the MEK5-MAPK6 module can phosphorylate MdNAC32, which regulates MdPBS1/2 expression. Overall, our results indicate that MT@SiO2 enhances the activity of the MEK5-MAPK6-NAC32-MdPBS1/2 module by inducing SA accumulation, resulting in enhanced resistance in apples to GLS. The use of the melatonin-based nanomaterial improved the efficacy of MT and highlights the potential use of conjugated nanomaterials to modulate disease resistance in apples. Our study also provides new insights into the involvement of NAC and MAPK pathways in plant defense response to microbial pathogens.Glomerella leaf spot (GLS), a fungal disease caused by Colletotrichum fructicola, is a major destructive disease of apples but research on control measures is limited. Melatonin (MT) is a phytohormone-like compound that affects plant growth and stress response but is prone to light-induced degradation, resulting in low stability and efficacy. Therefore, we developed a melatonin silicon-based nanomaterial (MT@SiO2) to enhance the stability of melatonin and increase its potential use on plants. Our results indicated that MT@SiO2 significantly enhanced apple leaf resistance to GLS. We demonstrated that MT@SiO2 at an optimal concentration of 50 μM significantly mitigated GLS infection in 'Gala' apples by elevating the level of salicylic acid. The core transcription factor gene MdNAC32 was identified in our transcriptome analysis and found to respond to both GLS infection and MT@SiO2 treatment. MdNAC32 directly activates the transcription of MdPBS1/2 which promotes the synthesis of SA. Transient overexpression and silencing experiments demonstrated that MdPBS1/2 positively regulates GLS resistance. In addition, we found that the MEK5-MAPK6 module can phosphorylate MdNAC32, which regulates MdPBS1/2 expression. Overall, our results indicate that MT@SiO2 enhances the activity of the MEK5-MAPK6-NAC32-MdPBS1/2 module by inducing SA accumulation, resulting in enhanced resistance in apples to GLS. The use of the melatonin-based nanomaterial improved the efficacy of MT and highlights the potential use of conjugated nanomaterials to modulate disease resistance in apples. Our study also provides new insights into the involvement of NAC and MAPK pathways in plant defense response to microbial pathogens.