Synthesis, Characteristics, Oil Adsorption, and Thermal Insulation Performance of Cellulosic Aerogel Derived fromWater Hyacinth

Abstract

Cellulosic aerogel from water hyacinth (WH) was synthesized to address the dual environmental issues of water hyacinth pollution and the production of a green material. Raw WH was treated with sodium hydroxide (NaOH) with microwave assistance and in combination with hydrogen peroxide (H 2 O 2 ). The results from X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, and scanning electron microscopy (SEM) showed that lignin and hemicellulose were markedly decreased after treatment, reducing from 24.02% hemicellulose and 5.67% lignin in raw WH to 8.32 and 1.92%, respectively. Cellulose aerogel from the pretreated WH had a high porosity of 98.8% with a density of 0.0162 g•cm −3 and a low thermal conductivity of 0.030 W•m −1 •K −1 . After modification with methyl trimethoxysilane (MTMS) to produce a highly hydrophobic material, WH aerogel exhibited high stability for oil absorption at a capacity of 43.3, 43.15, 40.40, and 41.88 (g•g −1 ) with diesel oil (DO), motor oil (MO), and their mixture with water (DO + W and MO + W), respectively. The adsorption remained stable after 10 cycles.

Insights into the effects of synthesis techniques and crosslinking agents on the characteristics of cellulosic aerogels from Water Hyacinth

“…The density of the aerogel cellulose samples was determined by eqn (1) : 20 where, D is the diameter (cm), H is the height (cm) and m is the mass of the sample (g).…”

“…While the porosity of aerogel materials ( P ) is determined by eqn (2) : 20 where, ρ is the density of the aerogel sample after drying (g cm −3 ) and ρ s is the density of the initial solid amount (g cm −3 ).…”

“…Then, the aerogel cellulose samples were lifted from the oil-filled beaker with a stainless steel mesh basket, air-dried for 30 seconds, and reweighed. The oil absorption capacity of the sample was calculated according to eqn (3) : 20 where, m o and m a are the mass of the aerogel cellulose sample before and after absorption. The same process was used to test the reusability and oil recovery of the aerogel cellulose materials for 10 cycles.…”

“…WH grows rapidly on the surface of rivers and canal systems, obscuring the water surface, and thus destroying water ecosystems as well as impeding water traffic. According to a previous study, 20 the cellulose content of WH is up to 50% of its raw weight. Therefore, it is considered to be a promising source for the preparation of aerogel cellulose and extracted materials, which could be applied in many different fields.…”

Invasive plants as biosorbents for environmental remediation: a review

“…For instance, the aquatic weed Eichhornia crassipes, commonly called water hyacinth, could flourish over 200 kg per ha each day (Huang et al 2021), and 125 tons per surface ha in half of a year (Istirokhatun et al 2015). Globally, its living form covered over 4 million hectares of wetlands, consequently, threatening the aquatic survival of other organisms and causing serious human issues such as mosquito-borne malaria, and the disturbance of the water transport network (Nguyen et al 2021e). Moreover, invasive plants are also associated with human well-being, including jeopardizing the integrity of agricultural systems, the balance of the economy, and public health.…”