Study: Effects of Alginate Salts in Coatings

WEDNESDAY, FEBRUARY 16, 2022


In a recently published study, researchers from the University of Genoa evaluated the effect of different alginate salts on the rheological and tensile properties of water-based architectural coatings.

Reported to be a seaweed derivative, alginate is commonly used as a thickener in the food and biomedical industries. The material is most known for its gelling ability with divalent cations and can exist as salt of the alginic acid with different monovalent cations.

Waterborne Coatings Research

For the research, scientists reportedly used a basic formulation containing cellulose as a thickener, while three different salts of alginic acid—sodium, potassium and ammonium—were investigated as alternative thickeners.

To evaluate the different viscoelastic nature of the coatings, researchers used a strain sweep test. According to reports, this test is also useful in defining a coating’s storage stability.

Through these types of viscosity curve evaluations and an additional Three Interval Thixotropy Test (3ITT), the team was better equipped to predict application phases and possible surface defects. In collecting additional data on the coatings, researchers also tested brush application processes on gypsum board to verify the coatings behavior.

After analyzing the coating applications, tensile properties of dried films were also measured to evaluate the counterion effect in the solid state.

The results of the study revealed that alginate counterions slightly influence the properties of the formulations during the storage.

The greater influence, however, was discovered through the evidence collected from the 3ITT results, which foresaw their application. Finally, the dried samples showed different tensile properties mainly depending on the concentration of the alginates rather than their type.

The study has since been published in Progress in Organic Coatings, Volume 163, February 2022.

Similar Coatings Studies

At the end of 2021, Egypt’s National Institute of Oceanography and Fisheries utilized algae in study on the development of environmentally friendly, antifouling marine paints.

For the study, researchers utilized extracts from four different Egyptian marine macroalgae: Ulva fasciata, Cymodocea nodosa, Padina pavonia and Colpomenia sinusa.

The water-soluble polysaccharides (WSP), proteins and lipids were combined with paint into sixteen compositions, aiming to act as a biocide to create environmentally safe, antifouling marine paints. Each type of these algal extracts was mixed solely by 2% (w/w) for WSP and protein and 1% (w/w) for lipid with the prepared paint formulation.

These paints were applied to unprimed steel panels, hung on a steel frame alongside a control and submerged in the Eastern Harbour of Alexandria, Egypt. Researchers collected sea water samples to analyze during assessment, as well as visually inspected and photographed the panels.

The best results were reportedly with panels coated with the formulations containing WSP. Researchers also reported that the measured hydrographical parameters were within the normal range indicating that the paint compositions were environmentally safe.

On the building materials side of things, some years ago, a team of researchers and architects from Australia investigated how buildings could be constructed with algae, generating energy and oxygen.

The group was led by Sara Wilkinson, a professor at UTS’s School of the Built Environment, and Peter Ralph, a professor in the university’s Plant Functional Biology and Climate Change Cluster. The two professors worked with UTS’s Research Engagement Manager, Dr. Brenton Hamdorf, and Paul Stoller, of architectural firm Atelier Ten, to bring their algae panel idea out of the lab and into the city.

In the feasibility study (supported by a grant from the City of Sydney), the team said it learned about some of the unique Australian challenges it faces, and compared the algae bioreactor system to any other renewable energy project in terms of upfront cost and eventual savings and sustainability.

   

Tagged categories: Architectural coatings; Asia Pacific; Coating chemistry; Coating Materials; Coating Materials - Commercial; Coatings; Coatings Technology; Coatings Technology; Colleges and Universities; EMEA (Europe, Middle East and Africa); Latin America; North America; Research and development; Water-borne; Waterborne coatings; Z-Continents

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