Potentialities of dandelion (Taraxacum mongolicum Hand.-Mazz.) flower extracts on gastric protection against Helicobacter pylori and characterization of its bioactive constituents.

OBJECTIVES: Dandelion has been shown to exert anti-inflammatory and anti-bacterial effects. Our study aimed to identify the effect and mechanism of dandelion flower extracts on H. pylori-induced gastritis and screen for novel antimicrobial substances. METHODS: Anti-H. pylori activities of water extracts(WEDF) and ethanol extracts (EEDF) of dandelion flowers were performed with disk diffusion method assay, MIC, and MBC. The H. pylori-induced model was constructed to examine the gastroprotective of EEDF using RUT, pathological analysis, and ELISA. RESULTS: EEDF exhibited better anti- H. pylori and urease inhibition activities than WEDF. In vivo studies, EEDF can reduce the adhesion of H. pylori to the gastric mucosa, alleviate gastric damage, and concurrently reduce the levels of TNF-α and IL-6 in gastric tissues. The six phenolic compounds showed urease inhibition effect (IC50: 2.99 ± 0.15 to 66.08 ± 6.46 mmol/mL). Among them, chlorogenic acid, caffeic acid, and luteolin also had anti-H. pylori activity (MIC: 64 - 256 µg/mL). CONCLUSION: EEDF exhibited anti-H. pylori, gastroprotective and anti-inflammatory effects. Chicoric acid and luteolin may be the main active compounds of dandelion flowers to exert anti-H. pylori, and worthy of further investigation.

Effect of passive versus active abdominal drainage on wound infection after pancreatectomy: A meta-analysis.

Following pancreatic resection, there may be a variety of complications, including wound infection, haemorrhage, and abdominal infection. The placement of drainage channels during operation may decrease the chances of postoperative complications. However, what kind of drainage can decrease the rate of postoperative complications is still a matter of debate. The purpose of this research is to evaluate the efficacy of both active and passive drainage for post-operation wound complications. From the beginning of the database until November 2023, EMBASE, the Cochrane Library and the Pubmed database have been searched. The two authors collected 2524 related studies from 3 data bases for importation into Endnote software, and 8 finished trials were screened against the exclusion criteria. Passive drainage can decrease the incidence of superficial wound infection in postoperative patients with pancreas operation (Odds Ratio [OR], 1.30; 95% CI, 1.06-1.60 p = 0.01); No statistically significant difference was found in the incidence of deep infections among the two groups (OR, 1.51; 95% CI, 0.68-3.36 p = 0.31); No statistical significance was found for the rate of haemorrhage after active drainage on the pancreas compared with that of passive drainage (OR, 0.72; 95% CI, 0.29-1.77 p = 0.47); No statistically significant difference was found in the rate of death after operation for patients who had received a pancreas operation in active or passive drainage (OR, 0.90; 95% CI, 0.57-1.42 p = 0.65); On the basis of existing evidence, the use of passive abdominal drainage reduces postoperative surface wound infections in patients. But there were no statistically significant differences in the risk of severe complications, haemorrhage after surgery, or mortality. However, because of the limited sample size of this meta-analysis, it is necessary to have more high-quality research with a large sample size to confirm the findings.

Transdermal administration of farnesol-ethosomes enhances the treatment of cutaneous candidiasis induced by Candida albicans in mice.

Cutaneous candidiasis, caused by Candida albicans, is a severe and frustrating condition, and finding effective treatments can be challenging. Therefore, the development of farnesol-loaded nanoparticles is an exciting breakthrough. Ethosomes are a novel transdermal drug delivery carrier that incorporates a certain concentration (10-45%) of alcohols into lipid vesicles, resulting in improved permeability and encapsulation rates compared to conventional liposomes. Farnesol is a quorum-sensing molecule involved in morphogenesis regulation in C. albicans, and these ethosomes offer a promising new approach to treating this common fungal infection. This study develops the formulation of farnesol-loaded ethosomes (farnesol-ethosomes) and assesses applications in treating cutaneous candidiasis induced by C. albicans in vitro and in vivo. Farnesol-ethosomes were successfully developed by ethanol injection method. Therapeutic properties of farnesol-ethosomes, such as particle size, zeta potential, and morphology, were well characterized. According to the results, farnesol-ethosomes demonstrated an increased inhibition effect on cells' growth and biofilm formation in C. albicans. In Animal infection models, treating farnesol-ethosomes by transdermal administration effectively relieved symptoms caused by cutaneous candidiasis and reduced fungal burdens in quantity. We also observed that ethosomes significantly enhanced drug delivery efficacy in vitro and in vivo. These results indicate that farnesol-ethosomes can provide future promising roles in curing cutaneous candidiasis. IMPORTANCE: Cutaneous candidiasis attributed to Candida infection is a prevalent condition that impacts individuals of all age groups. As a type of microbial community, biofilms confer benefits to host infections and mitigate the clinical effects of antifungal treatments. In C. albicans, the yeast-to-hypha transition and biofilm formation are effectively suppressed by farnesol through its modulation of multiple signaling pathway. However, the characteristics of farnesol such as hydrophobicity, volatility, degradability, and instability in various conditions can impose limitations on its effectiveness. Nanotechnology holds the potential to enhance the efficiency and utilization of this molecule. Treatment of farnesol-ethosomes by transdermal administration demonstrated a very remarkable therapeutic effect against C. albicans in infection model of cutaneous candidiasis in mice. Many patients suffering fungal skin infection will benefit from this study.

SPOP negatively regulates mTORC1 activity by ubiquitinating Sec13.

The mammalian target of rapamycin complex1 (mTORC1) can response to amino acid to regulate metabolism and cell growth. GATOR2 act as important role in amino acid mediated mTORC1 signaling pathway by repressing GTPase activity (GAP) of GATOR1. However, it is still unclear how GATOR2 regulates mTORC1 signaling pathway. Here, we found that K63-ubiquitination of Sce13, one component of GATOR2, suppresses the mTORC1 activity by lessening the inter-interaction of GATOR2. Mechanistically, the ubiquitination of Sec13 was mediated by SPOP. Subsequently, the ubiquitination of Sec13 attenuated its interaction with the other component of GATOR2, thus suppressing the activity of mTORC1. Importantly, the deficiency of SPOP promoted the faster proliferation and migration of breast cancer cells, which was attenuated by knocking down of Sec13. Therefore, SPOP can act as a tumor suppressor gene by negatively regulating mTORC1 signaling pathway.

Highly Stretchable Conjugated Polymer/Elastomer Blend Films with Sandwich Structure.

The physical blending of high-mobility conjugated polymers with ductile elastomers provides a simple way to realize high-performance stretchable films. However, how to control the morphology of the conjugated polymer and elastomer blend film and its response to mechanical fracture processes during stretching are not well understood. Herein, a sandwich structure is constructed in the blend film based on a conjugated polymer poly[(5-fluoro-2,1,3-benzothiadiazole-4,7-diyl)(4,4-dihexadecyl-4H-cyclopenta[2,1-b:3,4-b″]dithiophene-2,6-diyl)(6-fluoro-2,1,3-benzothiadiazole-4,7-diyl)(4,4-dihexadecyl-4H-cyclopenta[2,1-b:3,4-b″]dithiophene-2,6-diyl)] (PCDTFBT) and an elastomer polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene (SEBS). The sandwich structure is composed of a PCDTFBT:SEBS mixed layer laminated with a PCDTFBT-rich layer at both the top and bottom surfaces. During stretching, the external strain energy can be effectively dissipated by the deformation of the crystalline PCDTFBT domains and amorphous SEBS phases and the recrystallization of the PCDTFBT chains. This endows the blend film with excellent ductility, with a large crack onset strain exceeding 1100%, and minimized the electrical degradation of the blend film at a large strain. This study indicates that the electrical and mechanical performance of conjugated polymer/elastomer blend films can be improved by manipulating their microstructure.

Aligned Conjugated Polymer Nanofiber Networks in an Elastomer Matrix for High-Performance Printed Stretchable Electronics.

Conjugated polymer films are promising in wearable X-ray detection. However, achieving optimal film microstructure possessing good electrical and detection performance under large deformation via scalable printing remains challenging. Herein, we report bar-coated high-performance stretchable films based on a conjugated polymer P(TDPP-Se) and elastomer SEBS blend by optimizing the solution-processing conditions. The moderate preaggregation in solution and prolonged growth dynamics from a solvent mixture with limited dissolving capacity is critical to forming aligned P(TDPP-Se) chains/crystalline nanofibers in the SEBS phase with enhanced π-π stacking for charge transport and stress dissipation. The film shows a large elongation at break of >400% and high mobilities of 5.29 cm2 V-1 s-1 at 0% strain and 1.66 cm2 V-1 s-1 over 500 stretch-release cycles at 50% strain, enabling good X-ray imaging with a high sensitivity of 1501.52 µC Gyair-1 cm-2. Our work provides a morphology control strategy toward high-performance conjugated polymer film-based stretchable electronics.

Microstructural Evolution of P(NDI2OD-T2) Films with Different Molecular Weight during Stretching Deformation.

Conjugated polymers exhibit excellent electrical and mechanical properties when their molecular weight (Mw ) is above the critical molecular weight (Mc ). The microstructural changes of polymers under strain are crucial to establish a structure-performance relationship. Herein, the tensile deformation of P(NDI2OD-T2) is visualized, and cracks are revealed either along the (100) crystal plane of side chain packing or along the main chain direction which depends on the Mw is below or above the Mc . When Mw < Mc , the film cracks along the (100) plane under small strains. When Mw > Mc , the polymer chains first undergo stretch-induced orientation and then fracture along the main chain direction at large strains. This is attributed to the fact that the low Mw film exhibits large crystalline domains and the absence of interdomain connectivity, which are vulnerable to mechanical stress. In contrast, the high Mw film displays a nearly amorphous morphology with adequate entanglements, the molecular chains can endure stresses in the stretching direction to release substantial strain energy under greater mechanical deformation. Therefore, the film with Mw > Mc exhibits the optimal electrical and mechanical performances simultaneously, i.e., the electron mobility is retained under 100% strain and after 100 stretching-releasing cycles.

Enhancing the Molecular Order and Vertical Component Distribution of the P3HT/O-IDTBR System during Layer-by-Layer Processing.

The molecular order and vertical component distribution are critical to enhance the charge transport in layer-by-layer (LbL) processed active layer. However, the excessive inter-diffusion between donor and acceptor layers during LbL processing irrepressibly reduces their ordered packing. Herein, a novel tactic to optimize the molecular order and vertical morphology of the active layer through suppressing the deep penetration of (5Z,5'Z)-5,5'-((7,7'-(4,4,9,9-tetraoctyl-4,9-dihydro-s-indaceno[1,2-b:5,6 -b']dithiophene-2,7-diyl)bis(benzo[c][1,2,5]thiadiazole-7,4-diyl))bis(methanylylidene)) bis(3-ethyl-2-thioxothiazolidin-4-one) (O-IDTBR) to poly(3-hexylthiophene) (P3HT) film during LbL processing is proposed. This is enabled by inducing the formation of P3HT nanofibers through ultraviolet (UV) irradiation and solution aging. During the LbL processing, these nanofibers with high crystallinity reduce the damage of O-IDTBR solution to P3HT film and restrict the penetration of O-IDTBR into P3HT matrix. As a result, the P3HT nanofibers are preserved and the degree of vertical phase separation is enlarged in the LbL-processed film. Meanwhile, the molecular order of both components is enhanced. The resulting morphology that featured as intertwined P3HT nanofibers/O-IDTBR network efficiently promotes charge transport and extraction, boosting the power conversion efficiency (PCE) of the devices from 6.70 ± 0.12% to 7.71 ± 0.10%.

Highly Conductive Inkjet-Printed PEDOT:PSS Film under Cyclic Stretching.

Inkjet-printed conductive polymer PEDOT:PSS films have provided a new developing direction for realizing the stretchable transparent electrodes in optoelectronic devices. However, their conductivity and stretchability are limited as the presence of insulating PSS chains, rigid PEDOT conjugated backbone, and stronger inter-chain interactions in the pristine polymer, respectively. Here, we report a PEDOT:PSS film with preferable electrical and mechanical performances by inkjet-printing the formulated printable ink containing PEDOT:PSS, formamide (FA), d-sorbitol (SOR), sodium dodecyl benzene sulfonate (DBSS), and ethylene glycol (EG). The inkjet-printed uniform PEDOT:PSS film exhibits a high conductivity of 1050 S/cm and sheet resistance of less than 145 Ω/sq on both rigid and flexible substrates. Moreover, the resistance can remain stable after 200 cycles of stretching at 55% strain. The film also presents good stability during repetitive stretching-releasing cycles. The significantly enhanced conductivity of the film lies on the conformational transition of the backbone by secondary doping and post-treatment with FA as well as removing the excess PSS components after phase separation between PEDOT and PSS. Meanwhile, SOR serves as a plasticizer to break the original hydrogen bonds between PSSH chains and provides larger free volume for polymer chain extension, which gives the PEDOT:PSS film the ability to tolerant cyclic tension. This is one of the optimal performances currently reported for inkjet-printed stretchable PEDOT:PSS films. The inkjet-printed PEDOT:PSS film with high conductivity, stretching properties, as well as good biocompatibility exhibits promising prospects as anodes on optoelectronic devices.

An n-Type All-Fused-Ring Molecule with Photoresponse to 1000 nm for Highly Sensitive Near-Infrared Photodetector.

Most of all-fused-ring π-conjugated molecules have wide or medium bandgap and show photo response in the visible range. In this work, an all-fused-ring n-type molecule, which exhibits an ultrasmall optical bandgap of 1.22 eV and strong near-infrared (NIR) absorption with an onset absorption wavelength of 1013 nm is reported. The molecule consists of 14 aromatic rings and has electron donor-acceptor characteristics. It exhibits excellent n-type properties with low-lying HOMO/LUMO energy levels of -5.48 eV/-3.95 eV and high electron mobility of 7.0 × 10-4  cm2  V-1  s-1 . Most importantly, its thin film exhibits a low trap density of 5.55 × 1016  cm-3 because of the fixed molecular conformation and consequently low conformation disorder. As a result, organic photodetector (OPD) based on the compound exhibits a remarkably low dark current density (Jd ) of 2.01 × 10-10  A cm-2 at 0 V. The device shows a shot-noise-limited specific detectivity (Dsh *) of exceeding 1013  Jones at 400-1000 nm wavelength region with a peak specific detectivity of 4.65 × 1013  Jones at 880 nm. This performance is among the best reported for self-powered NIR OPDs.

An Amorphous n-Type Conjugated Polymer with an Ultra-Rigid Planar Backbone.

High charge carrier mobility polymer semiconductors are always semi-crystalline. Amorphous conjugated polymers represent another kind of polymer semiconductors with different charge transporting mechanism. Here we report the first near-amorphous n-type conjugated polymer with decent electron mobility, which features a remarkably rigid, straight and planar polymer backbone. The molecular design strategy is to copolymerize two fused-ring building blocks which are both electron-accepting, centrosymmetrical and planar. The polymer is the alternating copolymer of double B←N bridged bipyridine (BNBP) unit and benzobisthiazole (BBTz) unit. It shows a decent electron mobility of 0.34 cm2  V-1 s-1 in organic field-effect transistors. The excellent electron transporting property of the polymer is possibly due to the ultrahigh backbone stiffness, small π-π stacking distance, and high molecular weight.

Improving the Molecular Packing Order and Vertical Phase Separation of the P3HT:O-IDTBR Blend by Extending the Crystallization Period of O-IDTBR.

The morphology with strong molecular packing order and gradient vertical composition distribution associated with efficient charge transport and collection is critical to achieve high performance in nonfullerene solar cells. However, the rapid solidification process of the active layer upon the fast removal of solvent usually results in a kinetically trapped state with undesired morphology. Herein, we proposed a strategy to extend the crystal growth time of the acceptor via a high-boiling-point additive that selectively dissolved the acceptor. This was enabled by adding dibenzyl ether (DBE) to the poly(3-hexylthiophene) (P3HT):O-IDTBR blend in chlorobenzene (CB) solution. The combination of the kinetic study by time-resolved ultraviolet-visible (UV-vis) absorption spectra and detailed morphological characterization allows us to correlate the crystallization kinetics with the microstructural transition. The results show that the crystal growth time of O-IDTBR increases from 3 to 60 s upon the addition of 0.75% DBE, leading to further evolution of the molecular order of O-IDTBR during the DBE-dominated drying period. Meanwhile, O-IDTBR has more time to migrate toward the substrate owing to the larger surface energy. In addition, the onset of the crystallization process of P3HT is brought forward from 8 to 6 s due to the reduced solvent quality, which favors P3HT to crystallize into a fibril network. As a result, an optimized morphology that features the enhanced molecular packing order of P3HT and O-IDTBR as well as the vertical compositional gradient of O-IDTBR is obtained. Devices based on the optimized blend show more balanced charge transport and suppressed bimolecular recombination, giving rise to an improved power conversion efficiency (PCE) from 4.29 ± 0.04 to 7.30 ± 0.12%.

Optimizing the Intercrystallite Connection of a Donor-Acceptor Conjugated Semiconductor Polymer by Controlling the Crystallization Rate via Temperature.

The charge carrier transport of conjugated polymer thin film is mainly decided by the crystalline domain and intercrystallite connection. High-density tie-chain can provide an effective bridge between crystalline domains. Herein, the tie-chain connection behavior is optimized by decreasing the crystal region length (lc ) and increasing the crystallization rate. Poly[4-(4,4-bis(2-octyldodecyl)-4H-cyclopenta[1,2-b:5,4-b']dithiophen-2-yl)-alt-[1,2,5]-thiadiazolo[3,4-c]pyridine] (PCDTPT-ODD) is dissolved in nonpolar solvent isooctane and high ordered rod-like aggregations are formed. As the temperature increases, the changes in solution state and crystallization behavior lead to three different chain arrangement morphologies in the films: 1) at 25 °C, large and separated crystal regions are formed; 2) at 55 °C, small and well-connected crystal regions are formed due to faster crystallization rate and smaller nucleus size; 3) at 90 °C, the amorphous film is formed. Further results show that the film prepared at 55 °C has a smaller crystal region length (lc , 7.6 nm) and higher tie-chains content. Thus, the film exhibits the best device mobility of 2.3 × 10-3 cm2 V-1 s-1 . This result shows the great influence of crystallization kinetics on the microstructure of conjugated polymer films and provides an effective way for the optimization of the intercrystallite tie-chain.

To Reveal the Importance of the Crystallization Sequence on Micro-Morphological Structures of All-Crystalline Polymer Blends by In Situ Investigation.

In crystalline/crystalline polymer blend systems, complex competition and coupling of crystallization and morphology usually happen due to the different crystal nucleation and growth processes of polymers, making the morphology and crystallization behavior difficult to control. Herein, we probe the crystallization sequence during the film formation process (crystallize simultaneously, component A crystallizes prior to B or inverse) to illustrate the micro-morphology evolution process in poly(3-hexylthiophene) (P3HT) and poly[[N,N-bis(2-octyldodecyl)-napthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]- alt-5, 5'-(2,2'-bithiophene)] (N2200) blend using in situ UV-vis absorption spectra and in situ two-dimensional grazing incidence X-ray diffraction (2D GIXRD). When P3HT and N2200 crystallize simultaneously, a large-sized morphology structure is formed. When strengthening the solution aggregation of P3HT by increasing the solvent-polymer interaction, P3HT crystallizes prior to N2200. A P3HT-based micro-morphology structure is obtained. As the molecular weight of N2200 increases to a critical value (72.0 kDa), the crystallization of N2200 dominates the film formation process. A N2200-based micro-morphology is formed guided by N2200 domains. The results confirm that the crystallization sequence is one of the most important factors to determine the micro-morphology structure in all-crystalline polymer blends.

Increasing N2200 Charge Transport Mobility to Improve Performance of All Polymer Solar Cells by Forming a Percolation Network Structure.

The poor electron transport ability of the polymer acceptor is one of the factors restricting the performance of all-polymer solar cells. The percolation network of conjugated polymers can promote its charge transfer. Hence, we aim to find out the critical molecular weight (MW) of N2200 on the forming of the percolation network and to improve its charge mobility and thus photovoltaic performance of J51:N2200 blend. Detailed measurements demonstrate that when the MW of N2200 is larger than 96k, a percolation network structure is formed due to the chain tangled and multi-chain aggregations. Analysis of kinetic experiments reveals that it is the memory of the N2200 long chain conformation and the extent of aggregation in solution are carried into cast films for the formation of the percolation network. Thus, the electron mobility increases from 5.58 × 10-6 cm2V-1s-1 (N220017k) to 9.03 × 10-5 cm2V-1s-1 when the MW of N2200 is >96k. It led to a balance between hole and electron mobility. The µh/µe decrease from 16.9 to 1.53, causing a significant enhancement in the PCEs, from 5.87 to 8.28% without additives.

Efficient Nonhalogenated Solvent-Processed Ternary All-Polymer Solar Cells with a Favorable Morphology Enabled by Two Well-Compatible Donors.

The rational design of the morphology of ternary all-polymer solar cells (all-PSCs) having broadened photon harvesting is crucial to achieve high device performance. However, multicomponent blends often illustrated an unfavorable morphology such as large-sized phase separation due to their complicated interaction. Herein, we proposed to solve these problems by employing two donors with good miscibility (J51 and PTB7-Th), which also have similar compatibility with the acceptor (N2200). The resultant ternary blend films of J51:PTB7-Th:N2200 feature a uniform phase separation morphology due to the reduced competitive effect of intermolecular interactions. As an additional polymer donor, PTB7-Th could not only enhance the absorption of the binary blend but also act as a crystallization regulator to boost the face-on orientation in ternary blends. Accordingly, the J51:PTB7-Th:N2200 ternary blends exhibited improved sunlight absorption and higher and well-balanced carrier mobility accompanied by enhanced carrier extraction. With the nonhalogenated cyclopentyl methyl ether as the processing solvent, the ternary all-PSCs showed outstanding power conversion efficiency (PCE) higher than 9% when varying the PTB7-Th weight ratio in donors from 20 to 50%. Due to the PTB7-Th content holding a 30% weight ratio in donors, the ternary all-PSCs demonstrated the optimal PCE of 9.60%, which perform better than those of binary all-PSCs (PCE = 7.58 or 5.63%).

Insight Into the Role of PC71BM on Enhancing the Photovoltaic Performance of Ternary Organic Solar Cells.

The development of non-fullerene acceptor molecules have remarkably boosted power conversion efficiency (PCE) of polymer solar cells (PSCs) due to the improved spectral coverage and reduced energy loss. An introduction of fullerene molecules into the non-fullerene acceptor-based blend may further improve the photovoltaic performance of the resultant ternary PSCs. However, the underlying mechanism is still debatable. Herein, the ternary PSCs based on PBDB-T:ITIC:PC71BM blend were fabricated and its PCE was increased to 10.2% compared to 9.2% for the binary PBDB-T:ITIC devices and 8.1% for the PBDB-T:PC71BM PSCs. Systematic investigation was carried out to disclose the effect of PC71BM on the blend morphology and charge transport behavior. It is found that the PC71BM tends to intermix with the PBDB-T donor compared to the ITIC counterpart. A small amount of PC71BM in the ternary blend is helpful for ITIC to aggregate and form efficient electron-transport pathways. Accordingly, the electron mobility is increased and the density of electron traps is decreased in the ternary blend in comparison with the PBDB-T:ITIC blend. Finally, the suppressed bimolecular recombination and enhanced charge collection lead to high PCE for the ternary solar cells.

Balancing Crystal Size in Small-Molecule Nonfullerene Solar Cells through Fine-Tuning the Film-Forming Kinetics to Fabricate Interpenetrating Network.

The nanoscale interpenetrating network of active layer plays a key role in determining the exciton dissociation and charge transport in all small-molecule nonfullerene solar cells (AS-NFSCs). However, fabricating interpenetrating networks in all small-molecule blends remains a critical hurdle due to the uncontrolled crystallization behavior of small molecules. In this study, we proposed that the balanced crystal size between the donor and the acceptor is an essential prerequisite to construct optimal interpenetrating networks. We also provided a solvent additive strategy to reduce the gap of crystal size between the donor and the acceptor in S-TR:ITIC all small-molecule blend system through manipulating the solution state and film-forming kinetics. As a result, the crystal size of S-TR decreased and the crystal size of ITIC increased, leading to nanoscale interpenetrating networks. This optimized morphology improved the exciton dissociation efficiency and suppressed the bimolecular recombination, achieving almost double power conversion efficiency compared to the reference device. This work demonstrates that manipulation of the balanced crystal size of donor and acceptor may be a key to further boost the efficiency of AS-NFSCs.

Decreased domain size of p-DTS(FBTTh2)2/P(NDI2OD-T2) blend films due to their different solution aggregation behavior at different temperatures.

Nanoscale interpenetrating networks play a key role in determining the optoelectrical properties of functional blends. However, phase separated large domain sizes could probably be observed in pristine films composed of two crystalline components. For example, p-DTS(FBTTh2)2/P(NDI2OD-T2) 3/2 blend films with interpenetrating networks are obtained, however, large domain sizes are found when they are prepared from a 20 °C solution due to the simultaneous process of crystallization and phase separation during solvent evaporation. In this paper, we proposed to reduce the domain size of p-DTS(FBTTh2)2/P(NDI2OD-T2) blend films using their different solution aggregation behaviors at different temperatures. The aggregation of p-DTS(FBTTh2)2 molecules in chlorobenzene (CB) was insensitive to the solution temperature. However, the in situ absorption spectra of the neat P(NDI2OD-T2) solution from 80 °C to room temperature indicated that P(NDI2OD-T2) aggregation increased with decreasing temperature due to intrachain interactions. Therefore, in order to reduce the domain size, we employed a hot solution to prepare the blend films. During the solidification process, the majority of p-DTS(FBTTh2)2 molecules were confined in the P(NDI2OD-T2) networks prior to occurrence of severe p-DTS(FBTTh2)2 aggregation. Thus, the domain size of the p-DTS(FBTTh2)2 phase became smaller than that of the pristine films, leading to a decrease in the corresponding photoluminescence intensity of the blend films. In addition, the crystallinity of the blend films improved after thermal annealing, which resulted from the ordered alignment of p-DTS(FBTTh2)2 molecules facilitated by their enhanced diffusion ability. Based on the various morphologies, a possible phase diagram of the p-DTS(FBTTh2)2/P(NDI2OD-T2) blend system was depicted, which could be a guide to directly control the morphology of blend films.