Low Thermal Resistance Research Articles

Numerical analysis of thermal and hydraulic characteristics of flow boiling in oblique interconnected microchannel heat sinks

The rising demand for efficient cooling solutions in high-performance electronics underscores the importance of microchannel heat sinks (MCHS) with interconnected channels for thermal management. Despite advancements, limited research has explored the influence of oblique interconnectors on flow distribution and their impact on optimizing thermal and hydraulic performance. This study addressed this gap by numerically investigating the hydrothermal behavior of interconnected MCHS with oblique interconnectors, using HFE-7100 as the working fluid. Six geometric configurations were compared to a baseline parallel microchannel design to determine the optimal interconnector size and orientation. The study employed the Lee mass transfer model and the Volume of Fluid (VOF) approach to capture phase-change dynamics and flow behavior under varying mass fluxes (280.4–1121.6 kg/m2s) and heat fluxes (40–60 W/cm2). The results revealed two distinct flow regimes: suction-induced flows that enhanced thermal performance and disruptive flows that impaired it. One particular design (Case 1) demonstrated superior performance with a ∼26 % higher heat transfer coefficient, ∼23 % lower thermal resistance, and a 12.45 K reduction in wall superheat relative to the baseline, though at the expense of a ∼14 % increase in pressure drop. These findings highlighted the critical role of interconnector orientation in balancing thermal and hydraulic performance, offering a design guideline for future innovations in microchannel heat sinks.

Numerical Investigation of Nanofluid-based Flow Behavior and Convective Heat Transfer Using Helical Screw

Numerous industrial and home users have made use of heat transfer devices for the purpose of heat conversion and recovery. For the past half-century, engineers have worked tirelessly to perfect a heat exchanger design that cuts down on power use without sacrificing performance. Most methods of improving heat transfer work by either increasing the effective heat transfer surface area or creating turbulence, which results in lower thermal resistance. In this study, CFD was used to simulate Al2O3 and CuO nanoparticles in the adsorber tube of a parabolic solar collector with N=1 and N=2 turbulators at Re=20000, 60000, and 100000, respectively, and a turbulence strength of 5%. The turbulence strength was calculated as 5% of the total energy of the particles. Heat conduction is improved by the presence of nanoparticles in the base fluid. Therefore, nanofluids are candidates for alternative methods of heat transfer. Torsional turbulator models with N=2 have a greater output temp than those with N=1 because N=2 models have a higher practical heat level. The intake temp is raised from 35 to 46 degrees Celsius thanks to the presence of CuO nanoparticles in the two turbulator adsorber tubes that are close to one another. The Reynolds number invariably makes the Nusselt number higher. In addition, the Nusselt number demonstrates that there are a greater number of CuO nanoparticle models than Al2O3 nanoparticle models. In addition, CuO nanoparticles are more effective than Al2O3 at lowering pressure. When compared to the N=2 dual-turbulator mode, the N=1 single-turbulator mode has 34% more conflict. PECs are greater for models with two turbulators. Over a wide range of Reynolds numbers, the thermal PEC for N=2 models were 12 percentage points higher than that of N=1 models. CuO nanofluid receivers are superior to Al2O3 ones in their ability to convert solar energy into thermal energy. The two-turbulator model with a Reynolds number of 100,000 that uses CuO nanoparticles achieves the maximum thermal efficiency.

Experimental study on stability and heat transfer characteristics of separated heat pipe with a compressible volume condenser

A novel Separated Heat Pipe (SHP) system incorporating two magnetic spheres (SHPMS) was proposed for power generation (US Patent 11365653B2, 2022) using low-grade thermal energy, or offering both reliable emergency power and efficient heat transfer for spent fuel pools. This paper reports the experimental investigation on flow and heat transfer characteristics of the SHP, providing a foundation for the R&D of SHPMS. The SHP system features a unique shell-and-tube condenser structure, where the tube side serves as the cooling coil, while the shell side functions as the condenser chamber, with the dual roles of liquid storage and surge tank. The study researched the stability and heat transfer performance of the SHP under various parameters, including filling ratios ranging from 17 % to 98 %, cooling temperatures between 14 °C and 22 °C, and system pressures from 630 to 830 kPa. Analysis of instantaneous temperature, pressure, and flow patterns reveals the absence of high-frequency oscillations or alternating flow patterns, indicating that the condenser's condensing chamber may eliminate the instability in the SHP. Comparative analysis of the heat transfer coefficient and thermal resistance indicates that higher filling ratios and system pressures impair heat transfer performance, with optimal results at lower filling ratios (17 %–55 %) and pressure (630 kPa), where the higher heat transfer coefficient and lower thermal resistance were observed. Cooling temperatures showed little impact on heat transfer, allowing it to be chosen based on safety and energy efficiency needs. This study provides a new perspective on SHP systems with compressible volume condenser, offering a potential solution to address the instability challenges of SHP and the selection of operation parameters.

A study on the effect of channel structures on flow and heat transfer performance of cold plate with double-layer serpentine microchannel

As the power consumption of electronic components continues to rise, liquid cooling technology has become the mainstream solution for cooling electronic devices. This study designs a double-layer serpentine microchannel cold plate with a ribbed structure and firstly investigates the effects of the flow path on thermal–hydraulic performance of the cold plate. Through orthogonal numerical tests, the impact of rib height, number of rib truncations, rib truncation gap, and rib end deviation distance on thermal–hydraulic performance of cold plate is analyzed, along with their significance. Based on the results of the orthogonal test, the optimal rib structure parameters are determined. Results show that the parallel flow path has a more uniform flow distribution and approximately 2.5 % lower thermal resistance of the cold plate than the series flow path. Higher rib height leads to a higher convective heat transfer coefficient, more uniform internal flow distribution, and lower thermal resistance. When the rib height increases from 0.3 mm to 3 mm, the convective heat transfer coefficient increases 18 %, and the thermal resistance of the cold plate decreases 12 %. Compared to the initial structure, the optimized structure at the highest PEC has total thermal resistance and pressure drop reduced by 5.5 % and 7.4 %, respectively, while the structure with the lowest thermal resistance has a 7.9 % reduction in thermal resistance but a 27 % increase in pressure drop.

Single-Loop Triple-Diameter Pulsating Heat Pipes at Reduced Heat Input: A CFD Study on Inner Diameter Optimization

The geometric configuration, particularly the inner tube diameter, plays a significant role in the thermal performance of pulsating heat pipes (PHPs). Previous experimental research has demonstrated that single-loop triple-diameter PHPs (TD-PHPs) outperform single-loop single-diameter PHPs (SD-PHPs) and dual-diameter PHPs (DD-PHPs) in terms of thermal performance under moderate heating input powers ranging from 25 W to 75 W. However, a reduction in heat input from 75 W to 25 W leads to a diminished impact of TD-PHPs on the thermal performance. Therefore, to improve the overall performance of TD-PHPs, this study used two-dimensional transient computational fluid dynamics simulations to identify the optimal inner tube diameters for TD-PHPs at a low heat input by evaluating the thermal resistance of five TD-PHPs with various inner diameters. The findings reveal that the TD-PHP configuration exhibits minimum thermal resistance, with inner diameters of 4.5 mm for the upper arch (the condenser section), 4.0 mm for the wide branch, and 2.5 mm for the narrow branch, primarily due to its full circulation flow pattern. Furthermore, the overall heat transfer performance of the optimal TD-PHP was compared with that of an SD-PHP at low heat inputs (10 and 18 W), indicating that although the optimal TD-PHP shows lower thermal resistance, it does not significantly affect the start-up time.

Analytical generalized thermal resistance model for conductive heat transfer in pebble beds based on heat flux weighted temperature difference

A novel model for inter-particle contact thermal resistance based on analytical solutions is proposed. By applying the concept of heat flux weighted temperature difference in thermal resistance modeling for the first time, this model offers greater physical significance than traditional thermal resistance models. It effectively describes the dissipation in the heat transfer process and the influence of particle radius on thermal resistance, making it a generalized thermal resistance model suitable for multi-dimensional systems. The impact of applying different levels of uniform heat flux boundary conditions on thermal resistance is analyzed from the perspective of energy dissipation, revealing that a more uniform heat flux input results in lower thermal resistance. The effects of contact radius and particle size on the dimensionless generalized thermal resistance of inter-particle contact were studied, showing that the dimensionless resistance increases with larger particle contact radius and smaller particle size. Using the thermal discrete element method, the thermal resistance model with uniform heat flux density boundary conditions was applied to calculate the effective thermal conductivity of the pebble bed. Considering the distribution of contact radius, differences in effective thermal conductivity at various heights of the pebble bed due to different contact radii were examined and compared with the traditional fixed-coefficient contact resistance model. It was found that the difference between the two models decreases as the contact radius decreases. Finally, multiple sets of fixed contact radii were established under three different particle sizes, revealing that as the contact radius increases, the deviation between the new generalized resistance model and the traditional fixed-coefficient model rises from 8.18 % to 14.64 % for different particle radii.

Discussion on the thermal conductive network threshold of Al2O3/Co-continuous phase polymer composites

Achieving high thermal conductivity in polymer composites with micro or nanoparticle fillers are challenging. Typically, over 50 ​vol% filler loading is necessary to form a thermal conductive network. However, even with such a network in place, the increase in thermal conductivity may not be significant compared to that in electrically conductive composites. To clarify the ideal filler network structure, we endeavored to selectively disperse nano-sized Al₂O₃ nanoparticles at the interface of co-continuous SEBS/PA6 blends, with and without various filler surface modification methods. A thermal conductive network forms when all interface areas are fully covered by 2.56 ​vol% of Al2O3 nanoparticles (very close to theoretical loading content 2.29 ​vol%). In this case, the Al2O3 nanoparticle has the highest thermal conductive contribution (TCC). However, the absolute TCC values are extremely low because of the interfacial thermal resistance and it will decrease when the filler content exceeds 2.56 ​vol%, indicating that some nanoparticles are dispersed separately out of the existed thermal conductive network. These findings suggest that the construction of a connected thermal conductive network, relatively lower interfacial thermal resistance and the precise positioning of fillers within this network are essential for achieving high thermal conductivity composites.

Ultrasound combined with chemical hydrolysis as a pretreatment for microencapsulation of beetroot waste by spray and freeze drying

Sustainable and viable solutions are essential to reduce waste in the processing of agricultural products. In this study, ultrasound (US) pretreatments and chemical hydrolysis with alkaline hydrogen peroxide (AHP), both individually and combined (AHP+US), were applied to beetroot waste to assess their impact on microencapsulation by spray-drying (SD) and freeze-drying (FD). Process yield, functional and antioxidant characteristics, physical properties, thermal resistance, in vitro digestibility, as well as morphological and structural aspects of the particles under different conditions, were compared. Regardless of the pretreatment applied, the FD technique showed higher yields (83.56% - 89.15%) compared to SD (54.17%–57.88%). However, the combined pretreatment (AHP+US) provided the best results in terms of total phenolic content (TPC), betalains, and antioxidant capacity in both drying techniques, resulting in greater encapsulation efficiency (>90%) and improved bioaccessibility during in vitro digestion. Notable differences were also observed in the physical properties of the particles, with the SD samples showing lower moisture content (<4.3%) and higher water (>74.25%) and oil (>40.61%) retention capacity. However, these samples exhibited lower thermal resistance, with reductions in TPC content ranging from 10.10% to 33.70%. On the other hand, the FD process, due to its porous structure, provided greater thermal protection to the encapsulated compounds. The pretreatments also impacted the crystallinity index, increasing the amorphous zone of the material, which may favor certain industrial processes. Overall, the results of this study offer new perspectives for the application of US and AHP in the valorization of agro-industrial waste, highlighting the potential of these approaches for developing innovative and sustainable solutions in the management and reuse of food by-products, with possible applications in various other food matrices.

Enhanced Impact Resistance, Oxygen Barrier, and Thermal Dimensional Stability of Biaxially Processed Miscible Poly(Lactic Acid)/Poly(Butylene Succinate) Thin Films.

This study investigates the crystallization, microstructure, and performance of poly(lactic acid)/poly(butylene succinate) (PLA/PBS) thin films processed through blown film extrusion and biaxial orientation (BO) at various blend ratios. Succinic anhydride (SA) was used to enhance interfacial adhesion in PLA-rich blends, while blends near 50/50 formed co-continuous phases without SA. Biaxial stretching and annealing, adjusted according to the crystallization behavior of PLA and PBS, significantly influenced crystallinity, crystallite size, and molecular orientation. Biaxial stretching induced crystallization and ordered chain alignment, particularly at the cold crystallization temperature (Tcc), leading to a 70-80-fold increase in impact resistance compared to blown films. Annealing further enhanced crystallinity, especially at the Tcc of PLA, resulting in larger crystallite sizes. BO films demonstrated reduced thermal shrinkage due to improved PLA crystalline structure, whereas PLA-rich blown films showed higher shrinkage due to PLA's lower thermal resistance. The SA-miscibilized phase reduced oxygen transmission in blown films, while BO films exhibited higher permeability due to anisotropic crystal orientation. However, the annealing of BO films, especially at high temperature (Tcc of PLA), further lowered oxygen permeability by promoting the crystallization of both PLA and PBS phases. Overall, the combination of SA compatibilization, biaxial stretching, and annealing resulted in substantial improvements in mechanical strength, dimensional stability, and oxygen barrier properties, highlighting the potential of these films for packaging applications.

Poly(lactide)-Based Materials Modified with Biomolecules: A Review.

Poly(lactic acid) (PLA) is characterized by unique features, e.g., it is environmentally friendly, biocompatible, has good thermomechanical properties, and is readily available and biodegradable. Due to the increasing pollution of the environment, PLA is a promising alternative that can potentially replace petroleum-derived polymers. Different biodegradable polymers have numerous biomedical applications and are used as packaging materials. Because the pure form of PLA is delicate, brittle, and is characterized by a slow degradation rate and a low thermal resistance and crystallization rate, these disadvantages limit the range of applications of this polymer. However, the properties of PLA can be improved by chemical or physical modification, e.g., with biomolecules. The subject of this review is the modification of PLA properties with three classes of biomolecules: polysaccharides, proteins, and nucleic acids. A quite extensive description of the most promising strategies leading to improvement of the bioactivity of PLA, through modification with these biomolecules, is presented in this review. Thus, this article deals mainly with a presentation of the major developments and research results concerning PLA-based materials modified with different biomolecules (described in the world literature during the last decades), with a focus on such methods as blending, copolymerization, or composites fabrication. The biomedical and unique biological applications of PLA-based materials, especially modified with polysaccharides and proteins, are reviewed, taking into account the growing interest and great practical potential of these new biodegradable biomaterials.

4D Printing of Multifunctional and Biodegradable PLA-PBAT-Fe3O4 Nanocomposites with Supreme Mechanical and Shape Memory Properties.

4D printing magneto-responsive shape memory polymers (SMPs) using biodegradable nanocomposites can overcome their low toughness and thermal resistance, and produce smart materials that can be controlled remotely without contact. This study presented the development of 3D/4D printable nanocomposites based on poly (lactic acid) (PLA)-poly (butylene adipate-co-terephthalate) (PBAT) blends and magnetite (Fe3O4) nanoparticles. The nanocomposites are prepared by melt mixing PLA-PBAT blends with different Fe3O4 contents (10, 15, and 20 wt%) and extruded into granules for material extrusion 3D printing. The morphology, dynamic mechanical thermal analysis (DMTA), mechanical properties, and shape memory behavior of the nanocomposites are investigated. The results indicated that the Fe3O4 nanoparticles are preferentially distributed in the PBAT phases, enhancing the storage modulus, thermal stability, strength, elongation, toughness, shape fixity, and recovery of the nanocomposites. The optimal Fe3O4 loading is found to be 10 wt%, as higher loadings led to nanoparticle agglomeration and reduced performance. The nanocomposites also exhibited fast shape memory response under thermal and magnetic activation due to the presence of Fe3O4 nanoparticles. The 3D/4D printable nanocomposites demonstrated multifunctional multi-trigger shape-memory capabilities and potential applications in contactless and safe actuation.

Extremely Low Thermal Resistance of β-Ga2O3 MOSFETs by Co-integrated Design of Substrate Engineering and Device Packaging.

Gallium oxide (Ga2O3) emerges as a promising ultrawide bandgap semiconductor, which is expected to surpass the performance of current wide bandgap materials, like GaN and SiC, in electronic devices. However, widespread application of Ga2O3 is hindered by its extremely low thermal conductivity and lack of effective device-level thermal management strategies. In this work, Ga2O3 metal-oxide-semiconductor field-effect transistors (MOSFETs) are fabricated by conducting co-integrated design of substrate engineering with layer transferring and device packaging. 3D Raman thermography is introduced as a novel method to analyze the temperature distribution within the device, which provides valuable insights into their thermal performances. A high-quality Ga2O3-SiC heterogeneous integrated material is successfully fabricated with an extremely low interface thermal resistance of 6.67 ± 2 m2·K/GW. Compared to the homoepitaxial Ga2O3 MOSFETs, the degradation of Ion/Ioff in Ga2O3-SiC MOSFETs is decreased by 1.5 orders of magnitude, and that of Ron is decreased by 31%, showing the great thermal stability of Ga2O3-SiC MOSFETs. With the additional device packaging, a significant one order-of-magnitude reduction in the thermal resistance of the Ga2O3-SiC MOSFET is achieved, reaching a record-low value of 4.45 K·mm/W in the reported Ga2O3 MOSFETs. This work demonstrates an efficient strategy for device-level thermal management in next-generation Ga2O3 power and RF applications.

Preparation and thermal conductivity properties of CF/SR composites with high orientation and low interfacial thermal resistance based on the synergistic effect of magnetic field, torsional vibration and Diels-Alder reaction

Preparation and thermal conductivity properties of CF/SR composites with high orientation and low interfacial thermal resistance based on the synergistic effect of magnetic field, torsional vibration and Diels-Alder reaction

Integrated Technologies for Anti-Deicing Functions and Structures of Aircraft: Current Status and Development Trends

With the increasing adoption of composite materials in aircraft construction, traditional anti-icing technologies face significant challenges due to the low thermal conductivity and heat resistance of composite resins. These limitations have spurred the development of lightweight, efficient, durable, and cost-effective integrated anti-icing technologies as a critical area of research. This paper begins with an overview of advancements in electrothermal anti-icing and de-icing technologies for aircraft. It then explores the configurations and applications of functional-structural integration technology for anti-icing and de-icing, emphasizing pivotal technologies and current challenges in this field. Finally, the study forecasts the development trends in the multifunctional integration of thermal conductivity/insulation, anti-icing, and electromagnetic wave transparency/wave-absorbing properties. These advancements are driven by the evolution of composite materialization in aircraft and the progression of multi-electrical/all-electrical technologies. The objective is to provide a comprehensive guide for technological development in anti-icing, aiding researchers and relevant departments to further enhance the application of anti-icing technology in composite material aircraft.

Heat transfer performance and startup characteristics of separated gravity heat pipe

Separated gravity heat pipes, with distinct arrangements of evaporating and condensing sections, offer low thermal resistance, high heat transfer efficiency, and a simple structure, making them suitable for passive cooling of spent fuel pools through gravity-driven processes. In this study, a steady-state, one-dimensional, two-phase flow model is developed to analyze phase change heat transfer in a separated gravity heat pipe. The research investigates the impact of liquid filling rate and vacuum level on heat pipe operation. The findings reveal a notable increase in pressure drop inside the tube with higher liquid filling rates, which diminishes the adaptability of the heat pipe as pressure rises, resulting in a narrower range of effective liquid filling rates. Specifically, the liquid filling rate of the heat pipe ranges from 38 % to 72 % at P = 13.75 kPa and from 44 % to 68 % at P = 15.75 kPa. Additionally, a startup prediction model is formulated based on a thermal resistance network model using the ideal gas assumption. Two startup states—namely, the initial startup state and the subsequent startup state—are proposed for large-scale separated gravity heat pipe arrays. The heat pipe achieves the large-temperature-difference initial startup state at a 50 % liquid filling rate within 7 min before transitioning to the subsequent startup state. The vapor mass, heat transfer coefficient, and working fluid temperature initially increase and then decrease over time, with varying peak times. As the liquid filling rate increases, the maximum vapor mass also increases. The heat transfer coefficient peaks at a 60 % liquid filling rate before subsequently declining. The optimal liquid filling rate of 60 % is identified based on startup time, heat transfer coefficient, and overall heat transfer efficiency.

Experimental study on the thermal performance of a novel vapor chamber manufactured by 3D-printing technology

Vapor chamber holds great application potential in the field of heat dissipation for high-power electronic devices. This study developed a novel vapor chamber using 3D-printing technology to enhance heat dissipation for compact electronic devices. The vapor chamber was constructed from aluminum alloy with a structural dimension of 60×60×30mm3. In this work, the extended condensation structure of the vapor chamber was combined with an external cooling structure, resulting in a 729 % increase in the external heat dissipation area compared to the evaporation area in a limited space. Extensive experiments were conducted using deionized water as the working fluid under various cooling conditions and heat loads. The results showed that the vapor chamber was capable of maintaining a low thermal resistance at high power and high heat flux conditions, with a minimum thermal resistance of 0.087 °C/W when the heat load was 1000 W. At a cooling water flow rate of 0.1 L/s, the vapor chamber demonstrated the capacity to withstand a critical heat load of up to 1600 W, with the heat flux of 326 W/cm2. Compared to conventional vapor chambers, this novel vapor chamber is better able to achieve stable and efficient heat dissipation under high power and high heat flux conditions, especially in a limited space.

DETERMINATION THERMAL AND MECHANICAL PROPERTIES OF NANO CARBON, GRAPHITE AND GRAPHENE REINFORCED RECYCLING POLYPROPYLENE COMPOSITE SAMPLES

Polymer-based plastic materials occupy a major place in daily life. However, due to the nature of polymer materials, low thermal resistance and mechanical properties of these products, the need for new and sustainable materials in the industry has increased. With the rapid technological developments in advanced manufacturing industries such as aviation, marine, motor sports and defence industry, lightweight and high-strength composite products have become even more important. In this context, in this study, 1% carbon, graphene and graphite particle reinforced Polypropylene (PP) composite material mixed in a twin-screw extruder and MA/G series injection moulding machine standard tensile test sample produced. Melt Flow Index (MFI), Heat Deformation Test (HDT), tensile test, Shore-D hardness measurement and density tests performed on these test samples. According to the results obtained from these tests, the mechanical and thermal properties of the test samples produced from different composite materials were determined. The best mechanical and thermal properties occurred in the graphene particle. It formed in graphite and carbon, respectively.

Experimental investigation on the heat transfer characteristics of loop thermosyphon with a micro-channel evaporator under low heat flux

Loop thermosyphon is an efficient heat transfer device increasingly used in solar energy applications. The heat flux offered by solar radition is relatively restricted, but the mechanism of heat and mass transfer in loop thermosyphon at low heat flux remains ambiguous. Hence, a low heat flux loop thermosyphon experimental test platform was proposed and constructed in this paper to investigate the influences of filling ratio, heat load and cooling water temperature on the start-up and operation characteristics of the system. The outcomes reveal that instances of local dry-out, temperature overshoot, and geyser boiling are witnessed throughout the experimental process. With an increase in the filling ratio, the occurrences of local dry-out and geyser boiling gradually decrease and disappear, while the temperature overshoot becomes more prominent. The system’s optimal filling ratio is found to be approximately 80 %, and the lowest thermal resistance is 0.0053 K/W. No heat leakage is observed from the bottom of the evaporator to the liquid line. Except for the 40 % filling ratio, the system’s heat transfer efficiency exceeds 94 % for all other filling ratios, and the heat transfer performance is outstanding. The research results will contribute to the enhanced application of loop thermosyphon in solar energy utilization, possessing practical engineering significance. Additionally, they can also enhance the heat and mass transfer mechanisms of loop thermosyphon, having certain academic significance.

MXene-based semi-circle with a thin wire-shaped resonator wideband polarization-insensitive solar absorber

Fossil fuels’ supply peaks, decreases, and shortages are determined by their proven reserves, research, and consumption rates. With a large upfront cost, renewable and alternative energy sources are essential to solving the twin issues of energy and climate change. Solar absorbers are an excellent way to use renewable energy from the environment. This paper suggested an MXene-based semi-circle with a thin wire-shaped resonator (MSCWTWSR) solar absorber where the resonator layer consists of MXene material and Fe is used as substrate layer and the resonator has semi-circle and thin wire geometry which effectively absorbs the sun radiation with wideband. This proposed MSCWTWSR solar absorber works at 200–3000 (nm) wavelength and has more than 93% average absorption. The first band bandwidth of this MSCWTWSR solar absorber is 400 (nm), the second band is 530 (nm), and the third band is 470 (nm). This structure got more than 93% absorption in the AM 1.5 solar irradiation configuration. The structure gives in the Transverse electric (TE) field and Transverse magnetic (TM) field and the structure has polarization for insensitive. Furthermore, there is also investigated different incidence angles. A suggested article includes sections on testing for electric and magnetic intensities with a comparison table. The suggested solar absorber is employed in a distinct thermal heating application since MXene has a low thermal resistance and good thermal stability.

The Development of Poly(lactic acid) (PLA)-Based Blends and Modification Strategies: Methods of Improving Key Properties towards Technical Applications-Review.

The widespread use of poly(lactic acid) (PLA) from packaging to engineering applications seems to follow the current global trend. The development of high-performance PLA-based blends has led to the commercial introduction of various PLA-based resins with excellent thermomechanical properties. The reason for this is the progress in the field of major PLA limitations such as low thermal resistance and poor impact strength. The main purpose of using biobased polymers in polymer blends is to increase the share of renewable raw materials in the final product rather than its possible biodegradation. However, in the case of engineering applications, the focus is on achieving the required properties rather than maximizing the percentage of biopolymer. The presented review article discusses the current strategies to optimize the balance of the key features such as stiffness, toughness, and heat resistance of PLA-based blends. Improving of these properties requires molecular structural changes, which together with morphology, crystallinity, and the influence of the processing conditions are the main subjects of this article. The latest research in this field clearly indicates the high potential of using PLA-based materials in highly demanding applications. In the case of impact strength modification, it is possible to obtain values close to 800 J/m, which is a value comparable to polycarbonate. Significant improvement can also be confirmed for thermal resistance results, where heat deflection temperatures for selected types of PLA blends can reach even 130 °C after modification. The modification strategies discussed in this article confirm that a properly conducted process of selecting the blend components and the conditions of the processing technique allows for revealing the potential of PLA as an engineering plastic.