[en] Highlights: • The physicochemical property of triflumizole was regulated using different anions. • TILs could protect triflumizole against degradation under UV irradiation. • The IL forms of triflumizole reduced the toxicity to zebrafish. • TILs showed a higher bioactivity against Botrytis cinerea. -- Abstract: Triflumizole, a broad-spectrum systemic fungicide, has been widely used for the management of fungal diseases in plants. However, rapid photolysis and high risk to the aquatic environment limit its application. Ionic liquid (IL) forms of active pharmaceutical ingredients are innovative and promising agents that can optimize the application of the starting chemicals through the selection, or functionalization of the counterions (cation or anion). In this study, triflumizole was paired with various natural organic acids to develop novel ILs for improving the physicochemical properties and reducing the toxicity to fish. The results showed that the obtained ILs had low surface tension and lipophilicity and could protect triflumizole against degradation under UV irradiation as well as exhibit more excellent biological activity against Botrytis cinerea than triflumizole. The IL forms of triflumizole reduced the dosage and frequency of this fungicide, accordingly minimized the negative effect on environment. The IL contained salicylic acid as anion decreased > 4-fold toxicity to adult zebrafish over TFM. The results reported here create new application possibilities for imidazole fungicides and offer some heuristic rules for the design of active pharmaceutical ingredients-ionic liquids.

[en] Highlights: • A novel dual-responsive delivery system of IBA-silica nanospheres (IBA-SNs) was prepared. • The delivery system could enhance the stability of IBA in different conditions. • IBA-SNs showed obvious released efficiency and well duration, thus promoted the growth of plant. - Abstract: Indole-3-butyric acid (IBA) is an efficient plant growth regulator for promoting germination and the formation of rooting of various plants. Since it is unstable and presents the low utilization ratio, there is a compelling need to design an environmentally friendly formulation for IBA, which can reduce the loss of degradation and improve its utilization. Nano-sized controlled-release formulations can provide better durability and penetrate through the plant epidermis to efficiently deliver the agrochemicals to the target tissues. In this work, a kind of novel nano controlled-release formulation was prepared by conjugating the IBA and 3-glycidoxypropyltrimethoxysilane (GPTMS) through a covalent cross-linking reaction, and subsequently hydrolyzation and polycondensation with tetraethoxysilane. The resulting nanospheres were characterized by Fourier transform infrared spectroscopy, ultraviolet spectrophotometry, scanning electron microscope, and thermal gravity analysis. The results showed that the obtained nanospheres had a remarkable loading efficiency of IBA (about 43% w/w). The formation of covalent between IBA and GPTMS enabled the nanospheres with a good chemical stability that could protect against photo-degradation effectively. The released rate of the IBA from nanospheres was related to the temperature, pH value. With increased temperature as well as acidity and alkality, the release of the IBA was sped up. The IBA could also be released effectively from IBA-silica nanospheres by esterase, and the sustainable release characteristics of IBA-silica nanospheres were in conformity with the Ritger and Peppas equation. The IBA-silica nanospheres displayed excellent dual stimuli-responsive properties under esterase and weak acid conditions, and could obviously promote the growth of root and bud of pea. Thus, the IBA silica nanospheres prepared by covalent cross-linking reaction have a good potential application as a controlled-release formulation and environmentally-friendly plant growth regulator.

[en] Highlights: • HPAIL@meso-ZIF-8 composite material as a rhodamine B adsorbent was successfully prepared at room temperature. • The ZIF-8 and its composite showed improved adsorption capacity toward rhodamine B with high efficiency and selectivity. • The great performance of obtained nanoparticles was attributed to the excellent structural properties. • This work provided a promising and eco-friendly strategy to enhance adsorption property of ZIFs toward pollutants. The massive release of rhodamine B (RhB) to water system is an emerging problem, which dramatically threaten environment and human health. The development of an adsorbent with enhanced removal efficiency for RhB is urgently needed. Herein, we report an environment-friendly synthesis of high quality zeolitic imidazolate framework-8 (ZIF-8) and functional ionic HPAIL@meso-ZIF-8 in water-based system without heat treatment for improving its adsorption property. Guanidinium ionic liquids (ILs) could not only act as greener agents instead of volatile bases and toxic surfactants to efficiently control the nucleation and growth rate of ZIF-8, but also were incorporated as shell material to add specific adsorption sites. The relationship between nanoparticle structure and adsorption performance for RhB was systematically investigated. Due to high surface area (1167 m² g⁻¹), high porosity (0.79 cm³ g⁻¹), high crystallinity, nano size (about 100 nm) and monodispersity, the as-obtained ZIF-8 showed improved adsorption capacity toward RhB (80% removal efficiency). Heteropolyanion-based guanidinium IL@meso-ZIF-8 (HPAIL@meso-ZIF-8) exhibited the high RhB uptake capacity of 278 mg g⁻¹ (higher than most of the reported adsorbents) and effectively removed 99% of RhB within 15 min. The results showed that the adsorption process of prepared materials fitted well with pseudo-second-order kinetics and Langmuir isotherm model. The existence of mesopores in ZIF-8 facilitated the diffusion of RhB and the incorporated guanidinium IL played a significant role in enhancing the adsorption affinity. Moreover, the reusability results revealed the HPAIL@meso-ZIF-8 as a highly efficient adsorbent for RhB removal with satisfactory performance and structural stability. Therefore, HPAIL@meso-ZIF-8 is one of the most promising adsorbents for organic dye removal from water.

[en] Chemical pesticides have been widely used to increase the yield and quality of agricultural products as they are efficient, effective, and easy to apply. However, the rapid degradation and low utilization ratio of conventional pesticides has led to environmental pollution and resource waste. Nano-sized controlled-release formulations (CRFs) can provide better penetration through the plant cuticle and deliver the active ingredients efficiently to the targeted tissue. In this paper we reported novel conjugated nanospheres derived from 1-naphthylacetic acid (NNA), 3-aminopropyltriethoxysilane (APTES) and tetraethyl orthosilicate and their application as a controlled-release plant growth regulator. The NNA and APTES conjugate was prepared through a covalent cross-linking reaction and subsequent hydrolyzation and polycondensation to synthesize NNA–silica nanospheres. The release data indicated that the release of NNA was by non-Fickian transport and increased as particle size decreased. It was also found that the acidity–alkalinity was enhanced and as the temperature increased, the release of the active ingredient was faster. The nanoconjugate displayed a better efficacy in promoting root formation than NNA technical. The present study provides a novel synthesis route for CRFs comprising a pesticide, with long-duration sustained-release performance and good environmental compatibility. This method may be extended to other pesticides that possess a carboxyl group. (paper)

[en] Highlights: • Five novel herbicidal ionic liquids (HILs) based on picloram were synthesized and characterized. • The HILs exhibited moderate adsorption capacity and low leaching characteristic. • The negative effects of picloram on the aquatic environment were reduced. • A lower use dosage of picloram was achieved by application of HIILs. As a widely used herbicide, picloram has been frequently detected in the aquatic environment due to its high leaching potential and low adsorption by soil. To reduce aquatic environmental risk of this herbicide caused by leaching and runoff, five herbicidal ionic liquids (HILs) based on picloram were prepared by pairing isopropylamine, octylamine, octadecylamine, 1-methylimidazole, 4-methylmorpholine respectively. Their physicochemical properties including water solubility, octanol-water partition coefficient, surface activity, leaching, as well as soil adsorption were compared. The results showed that these properties could be adjusted by appropriate selection of counter cations. The HILs with long alkyl chains in cations had low water solubility and leaching characteristics, good surface tension and lipophilicity, as well as high soil adsorption. Compared with currently used picloram in the forms of potassium salts, HIL3 had more excellent herbicidal activity against broadleaf weeds and may offer a lower use dosage. The HILs based on picloram can reduce its negative effects on the aquatic environment and can be used as a desirable alternative to commercial herbicidal formulations of picloram in future.

[en] Highlights: • The nanosilica copper complexes of amino acids had systematic activity in plants. • The prepared complexes had a satisfactory efficacy against phytopathogenic fungi. • The nanosilica copper complexes of amino acids promoted the growth of plant. • The toxicity of copper to plants was reduced by the prepared complexes. - Abstract: The frequent use of traditional copper-based microbicides has led to the growing risk of toxicity to non-target organisms in the environment. In this work, nanosilica was conjugated with copper(II) complexes of L-glutamate (or glycine) to develop novel copper-based microbicides with good microbicidal activity, systemicity and desired safety to plant, and the obtained nanosilica-L-glutamate copper complexes (Silica-Glu-Cu) and nanosilica-glycine copper complexes (Silica-Gly-Cu) were characterized and evaluated by FT-IR, SEM, TEM, and XPS. The results showed that Silica-Glu-Cu and Silica-Gly-Cu exhibited satisfactory activities and long effective periods against Phytophthora capsica and Botrytis cinereal and could move upward and downward freely in cucumber seedlings. Moreover, Silica-Glu-Cu increased the fresh weights of cucumber and wheat seedlings by 0.4–6.4% at the concentrations of 50–200 mg/L of copper. Thus, the novel copper-based microbicides can reduce the frequency of using copper-based bactericides and phytotoxicity to plants.

[en] Highlights: • pH-responsive MSNs coated with complexes of Cu ions and tannic acid was established. • The PYR@MSNs-TA-Cu nanoparticles could improve photostability of pyrazoxystrobin. • The complexes coating enhanced deposition efficiency and adhesion ability of pesticide. • The nanoparticles showed a better fungicidal activity and lower toxicity to fish. In this work, a pH-responsive pesticide delivery system using mesoporous silica nanoparticles (MSNs) as the porous carriers and coordination complexes of Cu ions and tannic acid (TA-Cu) as the capping agent was established for controlling pyraclostrobin (PYR) release. The results showed the loading capacity of PYR@MSNs-TA-Cu nanoparticles for pyraclostrobin was 15.7 ± 0.5% and the TA-Cu complexes deposited on the MSNs surface could protect pyraclostrobin against photodegradation effectively. The nanoparticles had excellent pH responsive release performance due to the decomposition of TA-Cu complexes under the acid condition, which showed 8.53 ± 0.37%, 82.38 ± 1.67% of the encapsulated pyraclostrobin were released at pH 7.4, pH 4.5 after 7 d respectively. The contact angle and adhesion work of PYR@MSNs-TA-Cu nanoparticles on rice foliage were 86.3° ± 2.7° and 75.8 ± 3.1 mJ/m² after 360 s respectively, indicating that TA on the surface of the nanoparticles could improve deposition efficiency and adhesion ability on crop foliage. The control effect of PYR@MSNs-TA-Cu nanoparticles against Rhizoctonia solani with 400 mg/L of pyraclostrobin was 85.82% after 7 d, while that of the same concentration of pyraclostrobin EC was 53.05%. The PYR@MSNs-TA-Cu nanoparticles did not show any phytotoxicity to the growth of rice plants. Meanwhile, the acute toxicity of PYR@MSNs-TA-Cu nanoparticles to zebrafish was decreased more than 9-fold compared with that of pyraclostrobin EC. Thus, pH-responsive PYR@MSNs-TA-Cu nanoparticles have great potential for enhancing targeting and environmental safety of the active ingredient.