Don't try to do it like that: Do not concatenate strings to build a SQL command. It leaves you wide open to accidental or deliberate SQL Injection attack which can destroy your entire database. Use Parametrized queries instead.
string strSelect = @"SELECT * FROM essayT WHERE EsTittleF LIKE '%' + @SS + '%'";
using (SqlCommand cmd = new SqlCommand(strSelect, con))
{
cmd.Parameters.AddWithValue("@SS", Textbox1.Text);