To develop more economical and efficient heavy metal adsorbents, natural bentonite was employed as a raw material, and triethoxyvinylsilane served as a grafting agent to achieve the grafting bonding of sodium polyacrylate and bentonite. Structural alterations in the modified bentonite were analyzed through thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The adsorption and desorption characteristics of SAPAS-Bentonite and raw bentonite were compared and tested under various conditions, including time, temperature, pH, and lead ion concentration. The adsorption and desorption properties of sodium polyacrylate-grafted bentonite (SAPAS-Bentonite) were compared under various conditions (time, temperature, pH, and lead ion concentration). The results revealed that the modified method successfully achieved nano-scale coating of bentonite particles with sodium polyacrylate, leading to an increase in the maximum adsorption capacity of lead ions by 47.5%, reaching 165.73 mg g. A greater adsorption affinity for lead ions was exhibited by the outer sodium polycarboxylate portion of SAPAS-Bentonite compared with the inner bentonite. The adsorption of internal bentonite was limited by blocking when the adsorption of sodium polyacrylate did not reach the upper limit. The adsorption isotherm shifted from the Langmuir monolayer characteristic of the original bentonite to the S-shaped isotherm, reflecting the sodium polycarboxylate properties of SAPAS-Bentonite. Both bentonites demonstrated strong retention capacity for lead, with SAPAS-Bentonite surpassing raw bentonite in performance. This study provides valuable insights into the potential of SAPAS-Bentonite in the treatment of heavy metal pollution.

Control of the structure and morphology of clay crystals presents a challenge in the synthesis of materials for adsorption and catalysis. In the present study, direct crystallization of a phyllosilicate grafted with organosilyl (methylsilyl and phenylsilyl) groups on the surface of monodisperse spherical silica particles (2.6 μm) is reported. Methyl- and phenyltriethoxysilanes were allowed to react hydrothermally in a Teflon-lined autoclave with silica, MgCl2, and LiF in the presence of urea for 2 or 4 days. X-ray diffraction patterns revealed that the fine platy particles formed were a trioctahedral hectorite-like layered silicate. Greater temperature (150°C) was required to achieve homogeneous coverage of the original spherical silica particles with the hectorite-like particles. The diameter of the initial silica grains increased slightly to 3.0 μm after the hydrothermal reactions, while the original spherical shape and size distribution were maintained. Solid-state 29Si nuclear magnetic resonance analyses confirmed that the presence of resonances attributed to the RSi(OMg)(OSi)2 and RSi(OMg)(OH)(OSi) (R = methyl or phenyl) environments of the silicon proved the formation of covalent bonds between phyllosilicate sheets and the organic moieties. The crystallinity of the layered silicates increased when the reactions ran for a longer time (4 days).

Micron-grade natural vermiculite was modified by several physical and chemical treatments in order to increase the adsorption capacity of this material for B. A thermal exfoliation (T = 600°C) of pristine material, a chemical exfoliation through reaction with hydrogen peroxide (H2O2 35%), or grafting of a specific B complexant (i.e. N-methyl-D-glucamine: NMDG) led to an increase in the uptake of B at low initial concentrations of the aqueous solutions ([B] ≈ 5 mg L−1). The more efficient material is the NMDG-grafted clay, for which the adsorption uptake is four times greater than that of raw vermiculite, and reaches 0.04 mmol g−1. For all modified materials, the effect of the pH on B adsorption and the adsorption kinetics were studied and compared to raw vermiculite. Adsorption isotherms were also plotted and fitted well with the Freundlich equation.

The increased detection of pharmaceuticals in finished drinking water has become a growing cause of concern in recent years. The removal of atenolol, ranitidine, and carbamazepine by sepiolite, following functionalization of its surface by organosilane grafting, constituted the subject of this investigation. Silylated surfaces include octyl, γ-aminopropyl, 3-chloropropyl, and triphenyl moieties. The sorption of atenolol and ranitidine was higher on sepiolite functionalized with 3-chloropropyl, while carbamazepine showed a higher sorption on sepiolite with triphenyl groups. Filtration experiments of both ranitidine and carbamazepine on octyl- and triphenyl-sepiolite, respectively, showed a higher retention of ranitidine in comparison to carbamazepine, in spite of the fact that the number of sorption sites was lower due to its higher binding rate.

The objective of this study was to design new, functional, nanostructured materials from the abundant clay mineral kaolinite, in spite of development problems with the interlayer chemistry of kaolinite because of its non-swelling properties. A particular goal of this work was to graft, in a controlled way, alkylammonium groups onto the aluminol interlayer surfaces of kaolinite. This was successfully achieved by soft-chemical approaches, more specifically by the melting intercalation process of alkylammonium ionic liquids which were synthesized for this purpose. The resulting nanohybrid materials were characterized chemically and structurally by X-ray diffraction analysis, thermal analysis (TG/DTA), 13C cross polarization magic angle spinning nuclear magnetic resonance spectroscopy, and Fourier-transform infrared spectroscopy. The amount of grafted organic material was quantified from TGA results. Alkylammonium salts with a short alkyl chain were grafted directly using a melting reaction at 180°C under N2 involving the in situ displacement of dimethylsulfoxide (DMSO) from a DMSO-kaolinite pre-intercalate; for longer alkyl chains, the grafting was done in two steps. In the first step, the corresponding amino-alcohol was grafted into the kaolinite by displacement of DMSO from the interlayer space. The second step consisted of quaternarization of the grafted material by reaction with iodomethane or iodoethane.

Kaolinite is often used as a base for the synthesis of new organo-mineral nanomaterials designed for applications in industry and in environmental protection. To make the mineral structure more likely to interact with organic molecules, a kaolinite-methanol complex (KM) can be used. In the present study, different experimental procedures were tested to investigate the formation of the KM. The kaolinitedimethyl sulfoxide intercalation compound (KDS), either wet or dried, was used as a pre-intercalate. The samples obtained were characterized using X-ray diffraction, Fourier-transform infrared spectroscopy, CHNS elemental analysis, 13C CP-magic angle spinning nuclear magnetic resonance (MAS NMR), and 27Al and 29Si MAS NMR techniques. The method of density functional theory with dispersion corrections (DFT-D2) was used to explain the structure and to simulate the vibrational spectra of KM. Theoretical results were compared with experimental data. The most effective formation of the KM (d001 = 11.1 Å — wet; d001 = 8.7 Å — dried) was observed when the dried KDS precursor was used. In such conditions the degree of intercalation reached ~98% after 24 h of reaction time. As indicated by the CHNS elemental analysis, ~1/6 of the inner-surface OH groups were grafted by OCH3 groups. The esterification reaction was less efficient at higher temperatures or when wet KDS was used. In the latter case, the excess of very polar dimethyl sulfoxide molecules prevented intercalation of methanol and further grafting. Detailed analysis of the results of theoretical simulations revealed that the reaction of the KDS with methanol led to the formation of kaolinite with both grafted methoxy groups and intercalated methanol, and water molecules in the interlayer space. The spectra calculated revealed the contribution of individual vibrational modes into the complex bands, i.e. the energy of C-H vibrations was in the order: νasCHmet > νasCHmtx > νsCHmet > νsCHmtx.

The modification of halloysite nanotubes (HNTs) as fillers is very effective at improving the performance of polymers. A novel modification of HNTs through grafting dodecylamine onto their surfaces was conducted here. Owing to the improvement in dispersibility of HNTs in polytetrafluoroethylene (PTFE), the mechanical properties and wear resistance (in particular) of the dodecylamine-modified HNT-filled PTFE composite were enhanced significantly.

Grafting is a common technique used to impart desirable traits to a plant’s scion. Herbicide resistant rootstocks have the potential to confer non–genetically modified (non-GM) scions with herbicide tolerance while mitigating some societal concerns regarding GM crops and food. We examined the impacts of soybean cultivar and growth stage and environmental temperature on transference of glyphosate tolerance to conventional (CN) soybean scions when grafted to glyphosate-resistant (RR) rootstocks. Small CN/RR (scion/rootstock) plants (3-leaf stage) and medium-sized plants (6-leaf stage) were injured more than large plants (10-leaf stage) 34 d after treatment (DAT) with 0.84 and 1.68 kg ae ha−1 glyphosate. All CN/CN combinations died, and RR/RR were uninjured. The cultivar of the scion had a greater effect on glyphosate tolerance than the cultivar of the rootstock. CN scions 352 and 5418 were more tolerant than CN scion 5388 across all RR rootstocks 35 DAT when treated with 0.84 kg ha−1 glyphosate. CN/RR construct 5388/9392 was more sensitive to temperature compared with 352/9392. Less leaf regrowth of 5388/9392 was observed under the warmer temperature. Our experiments demonstrated that grafting imparted robust glyphosate tolerance across different plant sizes, environmental temperatures, and scion/rootstock cultivars.

Kaolinite and synthetic γ-Al(OH)3 (gibbsite or hydrargillite) were reacted with phenylphosphonic, phenylphosphinic and 2-nitrophenol-4-arsonic acids. The products were studied by powder X-ray diffraction, transmission electron microscopy/selected area electron diffraction/ energy dispersive X-ray/Fourier transform infrared and simultaneous thermogravimetric/differential thermal analysis. The acids were not intercalated but, instead, easily destroyed the structure of the minerals. Lamellar Al phenylphosphonate and aluminium phenylphosphinate and phenylarsonate with polymeric linear-chain structures were formed from kaolinite. The reaction between gibbsite and the same acids yielded almost identical products. No evidence of formation of grafted kaolinite derivatives after the reaction with phenylphosphonic acid was found.

Several new interlayer-grafted derivatives of kaolinite were synthesized by esterification of inner-surface hydroxyl groups with alkanols, diols and glycol mono-ethers starting with the dimethyl sulphoxide intercalate. The derivatives were characterized by X-ray powder diffractometry, thermal analysis, Fourier transform infrared spectroscopy and transmission electron microscopy. The grafted molecules are arranged in monolayers between the kaolinite layers, with typical basal spacings of ~11.3 Å. Rheological studies of aqueous dispersions of the modified kaolinites revealed an exponential increase of the yield value and apparent viscosity with increasing alkyl chain length of the grafted molecules.

Kaolinite was intercalated with n-hexylamine, n-octadecylamine and n-docosanamine, using methanol-kaolinite as the precursor. The intercalation compound with n-docosanamine presented the largest basal spacing for a kaolinite derivative thus far reported (64.2 Å). Five grafted derivatives of kaolinite were directly intercalated with n-hexyl- and n-octadecylamine. During intercalation, the grafted molecules rearrange from parallel to perpendicular orientation to the kaolinite surface, in order to maximize the interaction with the amine and minimize the interlayer expansion needed. The octadecylamine intercalation compounds were delaminated in toluene, accompanied by the deintercalation of the amine molecules. Thin kaolinite particles rolled into a halloysite-like morphology, but forming much smaller tubes, some of which possibly consist of single kaolinite layers. The delamination was more efficient with the grafted kaolinites than with raw kaolinite.

Tomato grafting is practiced worldwide as an innovative approach to manage stress from drought, waterlogging, insects, and diseases. Metribuzin is a commonly used herbicide in tomato but has potential to cause injury after application if plants are under stress. The influence of metribuzin on grafted tomato under drought-stress has not been studied. Greenhouse experiments were conducted in Raleigh, NC to determine the tolerance of drought-stressed grafted and non-grafted tomato to metribuzin. The tomato cultivar ‘Amelia’ was used as the scion in grafted tomato, and for the non-grafted control. Two hybrid tomato ‘Beaufort’ and ‘Maxifort’ were used as rootstocks for grafted plants. Drought-stress treatments included: no drought-stress; 3 d of drought-stress before metribuzin application with no drought-stress after application (3 d DSB); and 3 d of drought-stress before metribuzin application with 3 d of drought-stress after application (3 d DSBA). Metribuzin was applied at 550 g ai ha−1. No difference in injury from metribuzin was observed in grafted and non-grafted plants. However, at 7 and 14 d after metribuzin treatment (DMT), less injury was observed on tomato in the 3 d DSBA treatment (5 and 2% injury, respectively) than on plants in the 3 d DSB treatment (15 and 8% injury, respectively) or those that were never drought-stressed (18 and 11% injury, respectively). Photosynthesis and stomatal conductance measured prior to metribuzin application were reduced similarly in grafted and non-grafted tomato subjected to drought-stress. Photosynthesis and stomatal conductance of grafted and non-grafted tomato at 7 DMT was not different among drought-stress treatments or metribuzin treatments. Grafted and non-grafted tomato plants under drought-stress exhibit similar tolerance to metribuzin. The risk of metribuzin injury to grafted tomato under drought-stress is similar to non-grafted tomato.

Tomato rootstocks have been successfully used for eggplant production. However, the safety of herbicides registered in tomato has not been tested on grafted eggplant, which is a combination of tomato rootstock and eggplant scion. Greenhouse and field experiments were conducted to determine response of grafted eggplant on tomato rootstock to napropamide, metribuzin, halosulfuron, trifluralin, S-metolachlor, and fomesafen herbicides. In greenhouse experiments, herbicide treatments included pretransplant S-metolachlor (400 and 800 g ai ha−1), pre- or posttransplant metribuzin (140 and 280 g ai ha−1), and posttransplant halosulfuron (18 and 36 g ai ha−1). In field experiments, herbicide treatments included pretransplant fomesafen (280 and 420 g ai ha−1), halosulfuron (39 and 52 g ha−1), metribuzin (280 and 550 g ha−1), napropamide (1,120 and 2,240 g ai ha−1), S-metolachlor (800 and 1,060 g ha−1), and trifluralin (560 and 840 g ai ha−1). The eggplant cultivar ‘Santana' was used as the scion and nongrafted control, and two hybrid tomatoes ‘RST-04−106-T' and ‘Maxifort' were used as rootstocks for grafted plants. In both greenhouse and field experiments, there was no difference between grafted and nongrafted eggplant in terms of injury caused by herbicides. Metribuzin posttransplant at 140 and 280 g ha−1 caused 94 and 100% injury to grafted and nongrafted eggplant 4 wk after treatment. In field experiments, pretransplant fomesafen, napropamide, S-metolachlor, and trifluralin caused less than 10% injury and no yield reduction in grafted and nongrafted eggplant. However, metribuzin caused injury and yield reduction in both grafted and nongrafted eggplant. Metribuzin at 550 g ha−1 caused 60 and 81% plant stand loss in 2013 and 2014, respectively. Halosulfuron reduced yield 24% in both grafted and nongrafted eggplant compared to nontreated control in 2013 but did not reduce yield in 2014. The pretransplant S-metolachlor, napropamide, fomesafen, and trifluralin are safe to use on eggplant grafted onto tomato rootstock, and will be a valuable addition to the toolkit of eggplant growers.

Root-knot nematodes (RKNs), Meloidogyne spp., are considered, worldwide, as one of the main pathogens of solanaceous crops, including pepper (Capsicum spp.). Restrictions on the use of standard nematicides have motivated the development and use of resistant cultivars and rootstocks. Three genes in pepper, called Me1, Me3 and N, confer resistance to the three main RKN species (Meloidogyne incognita, Meloidogyne javanica and Meloidogyne arenaria). However, their effectiveness seems to be limited because nematode populations that have overcome the resistance have been found, leading to a search for new sources of resistance and strategies to preserve their effectiveness. In two greenhouses and over a 7-month growing period, we evaluated the resistance to M. incognita and the agronomic behaviour as rootstocks of nine pepper (Capsicum annuum) accessions – HDA330 (Me1 carrier), Serrano Criollo de Morelos, (Me3 carrier), Yolo Wonder (partially resistant) and another six accessions of unknown resistance originating from cultivars well adapted to the local growing conditions. The resistance conferred by the Me1 gene was more robust than that conferred by Me3. Resistance to M. incognita was found in four new accessions: P13, CTL, CT5, and P14. In P13, the level of resistance was similar to that of HDA330. The resistant accessions showed better agronomic behaviour than the susceptible accessions, which was most noticeable towards the final of the growing period. Some accessions constitute a potential resource for use in the genetic breeding of RKN-resistant rootstocks.

The distribution of the endemic threatened plant Camellia changii Ye (Family Theaceae) is restricted to a small area in southern China, and little else is known about its status in the wild. To provide information for the conservation of C. changii we investigated its distribution, population size and structure, and habitat, and assessed its conservation status. Surveys confirmed that the species grows in a narrow band along both sides of a 4 km long segment of a stream in Ehuangzhang Nature Reserve, under the discontinuous canopy of a secondary evergreen broadleaved forest on well-drained, acidic sandy loam soil. We found a total of 1,039 individuals of C. changii. The population has a high flowering rate but a low seed-setting rate. The population appears to be in decline because no seedlings and few young plants were evident. Our findings indicate that C. changii should be categorized as Critically Endangered on the IUCN Red List. We have recommended an integrated species-conservation plan for the species that includes patrolling the Ehuangzhang Nature Reserve to prevent plant removal, establishing an ex situ living collection that contains the entire wild genetic diversity (accomplished by grafting of short cuttings from all wild individuals), facilitating propagation for commercial use, and implementing reintroduction to augment the wild population.