Synthesis of hollow silica nanoparticles using poly (acrylic acid)-3,3’-diaminodipropylamine template

Abstract

Synthesis of hollow silica nanoparticles using poly (acrylic acid) (PAA)-amine aggregates as nano-sized template was proposed. The PAA-amine mixtures dissolve in water, but not in ethanol, therefore the mixtures can be a template for hollow particle in ethanol and can be removed from the core-shell particle by addition of water. In order to investigate effect of amines on hollow particle formation, four kinds of amines; ethylenediamine (EDA), N,N,N',N'-tetramethylethylenediamine (TED), 3,3'-diaminodipropylamine (DDA), triethylenetetramine (TTA), which interact with carboxylic acid of PAA were chosen. The PAA-each amine nanoparticles were formed with around 200 nm by dropping of PAA/amine mixtures in ethanol under the optimum conditions. Using the PAA-DDA template, hollow silica nanoparticles with spherical form were successfully prepared for the shortest reaction time in four hours. The primary amines and secondary amine of DDA work as not only cross-linker for PAA, but also sol-gel reacting catalyst. It can be clear from that the EDA with two primary amines also worked as sol-gel catalyst while the TED with two tertiary amines didn't. On the other hands, TTA with two primary and secondary amines also provided hollow silica nanoparticles, however, the silica shell of particles were mostly collapsed. It could be thought that the four amines of TTA promote sol-gel reaction, at the same time, high water content in the template induces molecular motion.

Rational Design of Waterborne Polyurethane Pressure Sensitive Adhesives for Different Working Temperatures

“…The further evidences are presented in the Supplementary Material . Recent works disclosed the strong interaction between the -COOH and -NH- or -NH 2 in ethanol at room temperature [ 29 ], and even the direct coupling formation of amide bond at room temperature from –COOH and -NH 2 on the graphene oxide surface [ 30 ] or on the Au (111) surface [ 31 ].…”

“…The further evidences are presented in the Supplementary Material. Recent works disclosed the strong interaction between the -COOH and -NH-or -NH 2 in ethanol at room temperature [29], and even the direct coupling formation of amide bond at room temperature from -COOH and -NH 2 on the graphene oxide surface [30] or on the Au (111) surface [31]. GPC was performed in the determination of the sol molecular weight of the four WPU-PSAs (Figure S7), while the molecular weights of the cross-linked parts of PSA2 and PSA3 could not be obtained by GPC [32,33].…”

Preparation of Hollow Silica Nanoparticles Using Fluorinated Surfactant and Fluorocarbon Solvents

“…Other hard templates are carbon [9], silica [10], and calcium carbonate particles [11,12]. The intermediate approach between soft and hard ISSN: 2734-9381 https://doi.org/10.51316/jst.149.etsd.2021.31.2.21 Received: February 11, 2020; accepted: July 22, 2020 templates is the nanoprecipitation of polymer to form nanoparticle templates for growing the hollow shells [13][14][15]. This nanoprecipitation is easy to be performed and a variety of polymers can be selected.…”

Effect of water soluble polymers on formation of Na2SO4 contained SiO2 microcapsules by W/O emulsion for latent heat storage

“…Na 2 SO 4 •10H 2 O is added in the water phase and SiO 2 shell is formed at W/O interface via sol-gel process. For the SiO 2 formation, the W/O interface should be ready for sol-gel reaction [7]. To trap Na 2 SO 4 •10H 2 O, five water soluble polymers with different functional groups were selected.…”