Cotton Effect Research Articles

Separation of chiral compounds using high performance liquid chromatography stationary phase based on covalent organic framework material TpPa-NH2-Glu

Covalent organic frameworks （COFs） are an emerging class of porous crystalline materials composed of multidentate organic units connected by covalent bonds. COFs have been demonstrated to exhibit great potential and research value in many fields， including gas storage and separation， photoelectric devices， fluorescence sensors， catalysis， drug delivery， dye and pollutant adsorption， and electronic devices， and so on. The COFs obtained by post-synthesis modification tend to exhibit high crystallinities and porosities， thereby rendering them suitable materials for use in the fields of chiral resolution， asymmetric catalysis， and chromatography. In this work， TpPa-NO2 was synthesized from 1，3，5-tricarbaldehyde phloroglucinol and 2-nitro-1，4-phenylenediamine， which was then reduced to TpPa-NH2. Subsequently， this material was modified with D-glucose via a post-synthesis modification strategy to obtain the TpPa-NH2-Glu. TpPa-NH2-Glu were characterized by nuclear magnetic resonance （NMR） spectroscopy， Fourier transform-infrared （FT-IR） spectroscopy， X-ray powder diffraction （XRD） analysis， etc. In the XRD pattern， the peaks observed at 4.7°， 8.1°， 11.1°， and 27° were attributed to the TpPa-NH2-Glu， and these peaks are consistent with previous reports， thereby confirming the successful synthesis of this derivative. In addition， circular dichroism experiments indicated that the TpPa-NH2-Glu exhibited a Cotton effect， further confirming the chiral COF was prepared. Subsequently， this material was immobilized on the surface of spherical silica gel particles via the net-wrapping method to prepare a stationary phase for high performance liquid chromatographic column. Using n-hexane-isopropanol （9∶1， v/v） or methanol-water （9∶1， v/v） as mobile phases at a flow rate of 0.5 mL/min， 16 racemates and two benzene-based positional isomers （o，m，p-nitroaniline and o，m，p-Iodoaniline） were successfully resolved by this chiral column. In addition， under methanol-water （9∶1， v/v） mobile phase conditions， five racemates were separated， among which propranolol hydrochloride， warfarin， and metoprolol reached baseline separation. Furthermore， under n-hexane-isopropanol （9∶1， v/v） mobile phase conditions， 11 racemates were resolved， among which ethyl 2-bromopropionate and 3-butyn-2-ol reached baseline separation. Meanwhile， the effect of temperature on the TpPa-NH2-Glu liquid chromatography column and the repeatability of the TpPa-NH2-Glu liquid chromatography column were also explored. The HPLC column prepared by TpPa-NH2-Glu had good repeatability， and its relative standard deviation （RSD） was 1.55% and 1.46%， respectively. It is demonstrated that the TpPa-NH2-Glu material has good resolution ability for chiral compounds.

Circularly polarized luminescence of helicenes: A data-informed insight.

Helicenes are an interesting scaffold for chiroptical properties and in particular circularly polarized luminescence (CPL). In this short review, we collect the luminescence (glum ) and absorption (gabs ) dissymmetry factors associated to the first Cotton effect of the electronic circular dichroism (ECD) spectrum. Considering the data for 170 [n]-helicenes (n= 4-11), overall we found reasonable correlations between glum and gabs . Despite a few notable exceptions, this would confirm a similarity in the stereochemistry of the ground and emitting excited states for most helicenes. These results may be useful in rationalizing chiroptical data and help chemists in designing new helicene structures with the desired CPL properties.

Noncentrosymmetric Supramolecular Hydrogen-Bonded Assemblies Based on Achiral Pyrazine-Bridged Zinc(II) Coordination Polymers with Pyrazinedione Derivatives

Reaction of M(OAc)2·xH2O (M, x = Zn, 2 and Co, 4), 1,4-dihydro-5,6-dicyano-2,3-pyrazinedione (H2CN2pyzdione), and pyrazine (pyz) affords two compounds of the same molecular formula {[M(H2O)6][M(CN2pyzdione)2(pyz)]·6H2O}n (M = Zn for 1 and Co for 2) in which discrete units of [M(H2O)6]2+ are linked to one-dimensional chains of [M(CN2pyzdione)2(pyz)]2– via multiple O–H···O hydrogen-bonding interactions and M2+-bound H2O molecules in [M(H2O)6]2+ also serve as linkers of hydrogen-bonded interstitial H2O molecules. Remarkably, 1 crystallizes in the monoclinic crystal system, the similar crystal system and unit cell parameters as 2, but with a space group distinct from 1 and 2, i.e., 1 is the noncentrosymmetric space group C2, whereas 2 is the centrosymmetric space group C2/m. This polar structure for 1 is induced by the presence of alternating arrangements of distinguishable two axial Zn–N bonds within [Zn(CN2pyzdione)2(pyz)]2– chains. Indeed, solid-state circular dichroism spectra of 1 exhibit significant Cotton effects, as evidenced by the polar space group C2. Moreover, these Cotton effects show clear temperature-dependence depending on contents of H2O molecules of 1.

Helical Synthetic Nanographenes with Atomic Precision

ConspectusUnderstanding and harnessing the properties of nanoscale molecular entities are considered as new frontiers in basic chemistry. In this regard, synthetic nanographene with atomic precision has attracted much attention recently. For instance, taking advantage of the marvelous bonding capability of carbon, flat, curved, ribbon-type, or cone-shaped nanographenes have been prepared in highly controllable and elegant manner, allowing one to explore fascinating molecular architectures with intriguing optical, electrochemical, and magnetic characteristics. This stands in stark contrast to other carbon-rich nanomaterials, such as graphite oxides or carbon quantum dots, which preclude thorough investigations because of complicate structural defects. Undoubtedly, synthetic nanographene contributes strongly to modern aromatic chemistry and represents a vibrant field that may deliver transforming functional materials crucial for optoelectronics, nanotechnologies, and biomedicine.Nonetheless, in many cases, synthesis and characterization of nanographene compounds are highly demanding. Low solubility, high molecular strain, undesired selectivity, as well as incomplete or excessive C-C bond formation are common impediments, that require formidable efforts to control the molecular geometry, to modulate the edge structure, to achieve accurate doping, or to push the upper size boundary. These endeavors are indispensable for establishing structure-property relationships, and lay down foundation for exploring synthetic nanographenes at a high level of sophistications.In this Account, we summarize our contributions to this field by presenting a series of helical synthetic nanographenes, such as hexapole [7]helicene (H7H), nitrogen-doped H7H, hexapole [9]helicene (H9H), superhelicene, and supertwistacene. This kind of giant synthetic nanographene reaches the size domain of carbon quantum dots, albeit has precise atomic structure. It provides a unique platform to study aromatic chemistry and chirality at the nanoscale. We discuss synthetic methods and point out, in particular, the strengths and pitfalls of Scholl oxidation, which are expected to be valuable for making synthetic nanographenes in general. In addition, we illustrate their exciting electrochemical and photophysical performance, which include, but are not limited to, reversible multielectron redox chemistry, record high panchromatic absorption, impressive photothermal behavior, and extremely strong Cotton effect. These unusual characteristics are convincingly traced back to their three-dimensional conjugated architectures, highlighting the critical roles of π-electron delocalization, heteroatom-doping, substitution, and molecular symmetry in determining nanographenes' properties and functions. Lastly, we put forward our understanding on the challenges and opportunities that lies ahead and hope this Account will inspire ever more ambitious achievements from this attractive area of research.

Soil Salinity Weakening and Soil Quality Enhancement after Long-Term Reclamation of Different Croplands in the Yellow River Delta

Saline soils are of great concern globally. Selecting the Yellow River Delta as a model site, the influence of reclamation on soil salinity and saline soil quality was investigated. Soil quality index (SQI) was applied to statistically analyze 210 soil profile samples collected at seven depth layers in 30 sampling sites among native saline soils and three croplands (peanut, cotton, and wheat) in May 2020. After reclamation, the soil salt content (SSC) reduced from 4.52 g/kg to 1.44 g/kg after reclamation, with the degree of soil salinity reducing from severe to slight. The nitrate nitrogen (NO3−-N) contents of peanut, cotton, and wheat croplands were 1.90, 2.02, and 4.29 times higher and the available phosphorus (AP) contents were 5.43, 3.57, and 8.77 mg/kg higher than that of the saline soils, respectively, while the soil ammonium nitrogen (NH4+-N) and available potassium (AK) contents were decreased. The NO3−-N, AN, and AP contents of the three croplands showed a significant surface aggregation at depth of 0–30 cm. SQI increased by 0.10, 0.09, and 0.02 after the reclamation with the enhancement effect of wheat and cotton was more pronounced. It was discovered that reclamation notably improved the soil quality as a result of crop growth and field management of fertilization and irrigation.

Balancing Compatibility and Gelability for High-Performance Cholesteric Liquid Crystalline Physical Gels

Liquid crystalline physical gels (LCPGs) have attracted increasing interest because of their mechanical properties and stimulus-response behaviors. However, due to their gelator properties such as thermal stability, gelation capability, and compatibility in liquid crystals, development of LCPGs with high performances still remains a huge challenging task. Herein, four novel gelators ((l)-PH, (d)-PH, (l)-P2H, and (d)-P2H) based on 1,4-benzenedicarboxamide phenylalanine derivatives containing one or two ethylene glycol groups have been designed and synthesized. It is found that the ethylene glycol group plays a significant role in improving the compatibility between the gelator and the liquid crystal. All of the prepared compounds can form stable LCPGs in P0616A. In particular, the storage modulus of LCPG with 9.0 wt % of (l)-PH with one ethylene glycol unit is higher than 106 Pa, which is similar to SmC gels and advantageous over previously reported nematic LCPGs. Furthermore, the prepared gels display a strong Cotton effect with hand-preferred twisted fiber networks and the self-assembled aggregates of (l)-PH can induce P0616A to form a cholesteric fingerprint structure. Thus, these low molecular weight gelators provide a strategy to construct high-performance cholesteric LCPGs for the realization of LC device applications.

Effect of Bt (Cry1Ac and Cry2Ab) and non-Bt cotton on the temporal variation of A. grandis and representatives of the Spodoptera complex in Tolima, Colombia

Transgenic cotton plants (Bacillus thuringiensis Berliner (Bt)) has significant influenced the integrated pest management around the world. In Colombia, Anthonomus grandis Boheman and Spodoptera complex are currently considered the main pests in cotton crops. Therefore, this study evaluated the effect of Bt (Cry1Ac and Cry2Ab) and non-Bt cotton on the population fluctuation during two years in Tolima region. A Pearson correlation matrix was carried out between the pest variables and yield, while climatic variables and insect populations were correlated in four phenological stages with Spearman rank correlations. Additionally, a factor analysis for mixed data was performed in order to compare the effect of genotypes on the population fluctuation of the insects. For A. grandis, no differences in their populations were presented. However, in yield non-Bt cotton plants showed a higher inverse correlation with the perforated bolls compared to Bt cotton. In relation to the Spodoptera complex, the Bt genotype had 67.4% fewer larvae compared to non-Bt cotton. Statistically significant differences were presented. However, there was not a total absence of the pest during the entire crop cycle. These results suggest that if refuge zones and pest management practices are not determined in the study area, Spodoptera complex could generate resistance to genetically modified plants.

The theoretical and experimental basis for calculating and justifying the parameters and regimes of the working areas of the cleaning zone of fibrous materials

In the article, there is the scheme and principle of the work of the cotton cleaner from small litter includes a composite pin drum with elastic elements and a vibrating mesh surface on elastic hinges. Theoretically, the torsional-vibrational motion of a two-mass system of a composite shoe drum has been studied, and the regularities of the dependence of changes in the parameters of the pin drum have been obtained. Based on the approximate analytical solution of the integro-differential equation, the law of angular vibrations of the net surface on the elastic supports of the cotton cleaner is studied. Experimental studies revealed regularities of loading and a change in the speed of rotation of the drum. The results of the full-factor experimental studies of the sample of the composite fluke drum are given. Based on the study of each of the three factors on the changes in the cleansing effect of cotton, the graphical dependencies of the parameters are postrene. The best values of the factors at which a high purifying effect of cotton from small weeds are achieved are recommended. Production tests revealed that the cleaning effect in comparison with the existing version of the drum spindle in the recommended increases by an average of 2.7%.

A sustainable approach to oil spill cleanup by kapok and waste cotton needle punched nonwoven blends

Natural materials that can absorb a large amount of oil have recently received a lot of interest as sorbents to clean up oil spills in seawater. In this work, kapok fibre was blended with different proportions of cotton fibres obtained as blow room waste from the textile industry to prepare nonwovens using carding and needle-punching techniques. The potential for oil sorption, oil retention, and water sorption of kapok/waste cotton nonwovens was investigated. FTIR, SEM, and surface contact angle of the fibres were determined since oil sorption depends on the fibres' physical and chemical properties. The effect of waste cotton and kapok fibre blend ratio on oil sorption and oil retention behaviour of kapok/cotton nonwoven was studied. The maximum oil sorption capacity of blended nonwoven (90/10, kapok/cotton) with areal density (150 GSM or g/m 2 ) was 45.36 g/g, 43.97 g/g, and 39.92 g/g for engine oil, vegetable oil, and diesel oil, respectively. Reusability test results suggest that after ten cycles, the oil absorbency of 150K/C 90/10 was 42.55 g/g, 40.61 g/g, and 36.45 g/g against engine oil, vegetable oil, and diesel oil, respectively. A comparison of the oil sorption capacity of kapok/waste cotton blends with other synthetic (Polypropylene) sorbents was also presented. According to our findings, kapok/waste cotton nonwovens could become an important sorbent for oil spill clean-up. • Sustainable oil sorbent was made from blends of kapok and waste cotton fibres. • The oil-to-pore volume occupied by fibre was explored for oil sorption capacity. • After ten cycles, K/C blend sorbents retained 76 % of engine oil. • The sorbents can be used as biofuel even after 10th cycle.

Assessment of Cry1Ac and Cry2Ab proteins in pollen of various transgenic cotton cultivars and effect on Apis mellifera L. colonies’ development

Assessment of Cry1Ac and Cry2Ab proteins in pollen of various transgenic cotton cultivars and effect on Apis mellifera L. colonies’ development

Decomposition and nitrogen mineralization of shredded cotton stalks and effect on soil microbes and succeeding sweet corn (Zea mays Saccharata L.)

Decomposition and nitrogen mineralization of shredded cotton stalks and effect on soil microbes and succeeding sweet corn (Zea mays Saccharata L.)

BINOL-like atropisomeric chiral nanographene.

Interest in making chiral polycyclic aromatic hydrocarbons (PAHs) or nanographenes (NGs) has greatly increased recently. To date, a majority of chiral nanocarbons have been designed based on helical chirality. Here, we describe a novel atropisomeric chiral oxa-NG 1 by the selective dimerization of naphthalene-containing, hexa-peri-hexabenzocoronene (HBC)-based PAH 6. The photophysical properties of the oxa-NG 1 and monomer 6 were investigated, including UV-vis absorption (λ max = 358 nm for 1 and 6), fluorescence emission (λ em = 475 nm for 1 and 6), fluorescence decay (15 vs. 16 ns), and fluorescence quantum yield, and it was found that the photophysical properties of the monomer are nearly maintained in the NG dimer due to its perpendicular conformation. Single-crystal X-ray diffraction analysis shows that both enantiomers cocrystallize in a single crystal, and the racemic mixture can be resolved by chiral high-performance liquid chromatography (HPLC). The circular dichroism (CD) spectra and circularly polarized luminescence (CPL) of the enantiomers of 1-S and 1-R were studied and the CD and CPL spectra exhibited opposite Cotton effects and fluorescence signals. Density functional theory (DFT) calculations and HPLC-based thermal isomerization results showed that the racemic barrier is as high as 35 kcal mol-1, suggesting a rigid chiral nanographene structure. Meanwhile, in vitro studies indicated that oxa-NG 1 is an efficient photosensitizer for white-light-induced singlet oxygen generation.

Working Conditions of the cotton gin

This comprehensive analysis delves into the various stages of cotton cultivation, examining their effects on the health of cotton growers. Through meticulous research, the study investigates the main factors influencing agricultural production and their direct influence on the well-being of workers involved in cotton farming. Furthermore, hygienic measures are developed and discussed as crucial safeguards to protect the health of these workers. The findings underscore the pressing need for proactive measures to address the health risks associated with cotton cultivation, providing valuable insights for policymakers, researchers, and stakeholders seeking to enhance the sustainability and welfare of the global cotton industry.
 Highlights:
 
 The study focuses on the health implications of cotton cultivation, examining its impact on the well-being of cotton growers.
 Hygienic measures are developed and proposed to safeguard the health of workers engaged in cotton farming.
 The research highlights the importance of proactive interventions to address health risks in the cotton industry, contributing to the sustainability and welfare of cotton growers.
 
 Keywords: cotton cultivation, health effects, agricultural production, hygienic measures, worker protection

Biochar Amendment in Combination with Endophytic Bacteria Stimulates Photosynthetic Activity and Antioxidant Enzymes to Improve Soybean Yield Under Drought Stress

The beneficial effects of biochar (BC) and plant growth-promoting bacteria (PGPR) to increase crop yields under harsh environments have been widely reported. However, the knowledge on the synergistic effects of BC and PGPR to induce drought tolerance in oilseeds is scant. In the present study, the effects of cotton sticks derived BC together with PGPR strains (Paraburkholderia phytofirmans and Bacillus sp.) were examined in water-stressed soybean plants. Initially, the BC application rates (1% and 2%) for soybean were optimized in a pilot experiment (experiment I), and the most effective level (1%) was selected for further studies together with PGPR in the second experiment. The soybean plants were raised in pots under semi-controlled conditions and were subjected to drought stress (25–30% water holding capacity) at pod formation stage. In comparison with control, the drought-mediated decrease in photosynthetic pigments and gas exchange characteristics was markedly lower in BC and PGPR-treated plants. However, the maximum increase in photosynthetic (12–30%) and the enzymatic antioxidant activities (5–20%) was recorded in plants treated with BC + P. phytofirmans, whereas no further significant increase was observed in plants treated with combined BC and Bacillus sp. under water deficit conditions. Similarly, the combined BC and P. phytofirmans application considerably increased the grain yield (14%) under drought stress conditions. We conclude that the combined application of BC + P. phytofirmans could be utilized as an effective strategy to improve soybean yield in dry arid regions.

BEMISIA TABACI BIOLOGICAL AND LIFE TABLE PROPERTIES ARE AFFECTED BY BT AND NON-BT COTTON CULTIVARS (GENNADIUS)

Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae) is a common cotton pest that causes massive economic losses yearly, directly or indirectly. This study aimed to investigate the effects of Bt cotton on the biological and life table parameters of B. tabaci under controlled conditions.The incubation, nymphal, and pupal periods were recorded as shortest on Bt and longest on non-Bt cultivars. It completed immature stages within 27.8, 28.2, and 28.6 days on Bt, whereas it took 30.4 days on the non-Bt cultivars. Adult longevity increased in Bt cultivars while decreasing innon-Bt cultivars. The male lived for a shorter duration and was smaller than the female. Pre-oviposition was higher in non-Bt cultivars and lowered in Bt cultivars. Bt cultivars had longer oviposition periods than non-Bt cultivars. Fecundity was relatively higher on Bt (57.5, 55.1, and54.2 eggs/female) but reduced on non-Bt (48.2 eggs/female). The life table parameters were also modified using different cotton cultivars. Age-survivorship declined with age, and the highest mortality was recorded at the egg stage, with non-Bt having a longer life span than Bt cultivars. In the egg stages, life expectancy was similarly greater. The net reproductive rate (RO) was recorded as the highest, and the intrinsic rate of increase (rm) was the lowest on Bt cultivars. Non-Bt cultivars had the highest finite rate of increase, mean generation time, and population doubling time, while Bt cultivars had the lowest. The experimental findings showed that Bt was slightly more suitable for developing B. tabaci than non-Bt cultivars.

Preparation of superhydrophobic, antibacterial and photocatalytic cotton by the synergistic effect of dual nanoparticles of rGO-TiO2/QAS-SiO2

In this study, the cotton fabric was endowed with superhydrophobic, antibacterial, and photocatalytic properties by a simple and easily-operated coating method. The optimal dual-particle coating, firmly adhered to the textile surface using polydimethylsiloxane (PDMS) as a binder, was obtained with the mixture of reduced graphene oxide-added titanium dioxide (rGO-TiO 2 ) and quaternary ammonium-functionalized silica (QAS-SiO 2 ), under the most appropriate mass ratio. The experimental results reveal that the water contact angles (CAs) of the optimal-treated cotton fabric can reach up to154°, and the bactericidal effect against Escherichia coli and Staphylococcus aureus is over 99 %, with the degradation rate for methylene blue solution as high as 98 %. On top of the excellent self-cleaning and bacterial shielding capabilities of the coating, its enhanced performance mentioned above can be maintained well against repeated washing, continuously abrasion, strong acids/bases and UV rays. Meanwhile, the finding suggests that the coating does not affect the strength of the fabric, and can retain the original deformability of the fabric. Most notably, the application of the coating method can cover a wide range of materials, including a variety of textiles as well as nontextiles such as paper, stainless steel etc. In short, this novel coating method is eco-friendly and strongly feasible, which paves the solid way for great potential in a wide range of application. • Cotton was functionalized with nano-silica and nano-titanium dioxide particles. • The processed cotton fabric was endowed with super-hydrophobicity and excellent photocatalytic activity. • The bactericidal effect of cotton against Escherichia coli and Staphylococcus aureus is over 99 %. • The degradation rate of MB solution finally reached the maximum 98 %. • The functional finishing will not visibly affect other properties of cotton fabrics.

Influence of variants of grid bars and spiky cylinders on the cleaning effect of cotton on small waste

The article examines the use of grid bars and spiky cylinders in a small-grained cotton ginning machine. The results of the experimental tests were also compared with the results obtained in the existing structure, and the data are presented in the tables. When the recommended grid bars were installed on a hexagon (edge length 70.8 mm), the cleaning effect of the machine increased by 2.7%, and after cleaning, the amount of small waste in the raw cotton decreased to 0.07%.

Development and reproduction of Tetranychus cinnabarinus (Acari: Tetranychiae) on transgenic insect-resistant cotton plants

The effects of two insect-resistant transgenic cotton strains (transgenic Bt pest-resistant cotton Zhongkangza 5 and Lumianyan 23, transgenic Bt+CpTI pest-resistant cotton sGK958 and Zhongmiansuo 45) on the growth and reproduction of Tetranychus cinnabarinus was examined in comparison with non-transgenic cotton (K836) at 70% relative humidity and 30±0.5 ℃. The results showed that T. cinnabarinus fed on transgenic Bt cotton and transgenic Bt+CpTI cotton differed significantly from those on conventional cotton in development time of various stages. Furthermore, the development times of mites on transgenic Bt cotton and transgenic Bt+CpTI cotton were the same, but the development times of T. cinnabarinus fed on transgenic Bt pest-resistant cotton Zhongkangza 5 and Lumianyan 23 were different, as well as the development times of T. cinnabarinus fed on transgenic Bt+CpTI pest-resistant cotton sGK958 and Zhongmiansuo 45. The pre-oviposition period, oviposition period and the female mite life span were longer (1.44 d, 12.71 d, and 14.11 d respectively) on non-transgenic cotton than on transgenic cotton. The maximum fecundity was 75.61 eggs per female on non-transgenic cotton and the minimum fecundity (54.68 eggs per female) was observed in mites fed on sGK958. The net reproductive rate (R0) was the highest (55.000) on non-transgenic cotton, but was the smallest (37.219) on Zhongkangza 5. The intrinsic rate of increase (rm) was the highest (0.454) on non-transgenic cotton, but was the smallest (0.246) on Zhongkangza 5. The finite rate of increase (λ) was the highest (1.575) on non-transgenic cotton, but was the smallest (1.278) on Zhongkangza 5. The population doubling time (DT) was the shortest (1.526 d) on non-transgenic cotton, but was the longest (2.823 d) on Zhongkangza 5. The results of this study indicated the negative effects of transgenic cotton on the development and reproduction of T. cinnabarinus was significant: the larvae had the lowest survival rate after feeding on five kinds of cotton, while deutonymphs had the highest survival rate; the hatching rate and deutonymph survival rate of T. cinnabarinus fed on CK were the highest, while the hatching rate and larval survival rate of the sGK958 were the lowest. Transgenic insect-resistant cotton basically showed significant effects on the development period of each stage and the whole generation of T. cinnabarinus, but there were no significant differences between univalent transgenic Bt cotton and bivalent transgenic Bt+CpTI cotton.

Charge‐Transfer Complex Doped Photothermal Hydrogels for Discriminating Circularly Polarized Near‐Infrared Light

AbstractHydrogels behave as potential candidates to investigate circularly polarized light (CP)‐matter interaction, which however suffer from small sensitivity towards circular polarization. Here we report a general protocol to build hydrogels from π‐conjugated amino acids with coassembled charge‐transfer (CT) complexes, covering a wide scope of donors and acceptors, which were incorporated into stable hydrogel matrices. CT complexes formed block coassemblies with gelators, induced the emergence of macroscopic chiral helices, where efficient chirality transfer occurs to realize tunable Cotton effects from visible light to NIR‐I region depending on the structures of CT pairs. The hybrid hydrogels showed tunable photothermal performances with excellent heating‐cooling cycling durability. Circularly polarized NIR light selectively triggered gel‐solution phase transition at different timescales. Left‐ and right‐CP illumination generates up to 2.5 folds difference in gel collapse time that allows for direct discrimination by naked eyes.

Chiral binol-[4]helicene hybrids: Strong solid-state organic emitters with aggregation-enhanced emission and chiroptical properties

Chiral organic fluorescent materials have attracted broad attention for their application in various chiroptical devices. Helicenes possess special helical structure and unique optical properties, and have been utilized to develop chiral organic fluorescent materials with excellent chiroptical performance. However, the low luminescence efficiency of helicene-based chiral fluorescent materials in solid state limits their practical applications. In this work, chiral organic fluorescent emitters with helicene moiety have been developed from binaphthanol structure. These BINOL [4]helicene compounds display aggregation-enhanced emission properties, and have strong blue emission in solid state with fluorescent quantum yield up to 0.67. The DFT calculation reveals that these compounds have highly twisted molecular structures. Thus, the excellent fluorescent properties in solid state could be aroused by the highly contorted molecular structures, which could limit the π-π stacking of adjacent molecules in solid state. The enantiomers of these compounds show strong Cotton effects in circular dichroism spectra, and the molecules with 4-methoxy phenyl moiety exhibit circularly polarized luminescence properties.