Preparation and characterization of 1-naphthylacetic acid–silica conjugated nanospheres for enhancement of controlled-release performance

Abstract

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.

Synthesis of a novel nanopesticide and its potential toxic effect on soil microbial activity

“…Prado et al (2011) recently reported a method to modify hexagonal mesoporous silica with carboxyl acids to prepare a new kind of nanospheres which were subsequently used as a support for the controlled release of 2,4-D and picloram. And there are also three new formulations that have recently been proposed involving the use of silica (Ao et al 2013;Mei-Rong et al 2012) or calcium carbonate (Qian et al 2011) nanoparticles as carriers, for the slow release of pesticide. And different nanomaterials including nanocrystals (Rabinow 2004;Zhang et al 2010), nanosuspensions (Pathak et al 2004), nanocages (Martin and Kohli 2003), nanoencapsulates (Schneider et al 2000), and functionalized nanocarriers (Sershen et al 2000) have been applied to deliver some potential materials.…”

Pesticide Encapsulation at the Nanoscale Drives Changes to the Hydrophobic Partitioning and Toxicity of an Active Ingredient

“…This notion is supported by the observed increase in toxicity from the SF. If capsule leakage is the mechanism for release, small pesticide capsules would release active ingredients more rapidly than large capsules [33]. Our partitioning experiment did not suggest a difference in γ-cyhalothrin release rate between SF and LF, though enzymatic degradation of capsules in the gut of C. dubia could affect the capsule integrity.…”

Engineering of Peglayted Camptothecin Into Nanomicelles and Supramolecular Hydrogels for Pesticide Combination Control

“…Recently, nanotechnology represents a new impetus for sustainable agriculture development (Zhao et al, 2018), and it has been receiving increasing interest in the pesticide sector with the development of a range of nanopesticides (Khot et al, 2012;Kah et al, 2013;Melanie, 2015), since nano-pesticide formulations may offer benefits like increasing solubility and bioavailability, reducing the amount of active ingredients used and the development of resistance, as well as providing ingredient protection against premature degradation (Sasson et al, 2007;Kah et al, 2013;Kah and Hofmann, 2014). Polymeric nanospheres and nano-capsules, together with nanogels and nanofibers, even more complex nano-formulations, have been developed for the delivery of pesticides, and primarily aimed at increasing solubility or slow and controlled release profile of the active ingredients serving as protective reservoirs (Anton et al, 2008;Ao et al, 2012;Bhagat et al, 2013;Memarizadeh et al, 2014;Sharma et al, 2017). Furthermore, several nanocarriers, such as nanocapsules (Shen et al, 2010), micelles (Dong et al, 2012) and hydrogels (Ha et al, 2013) can deliver two different drugs for combination therapy.…”